A 1000-watt heater operating for one hour would provide 3412 BTU of heat. Burning a gallon of propane would provide about 91500 BTU of heat. You would have to operate the 1000-watt heater for 27 hours to get the heat produced by a gallon of propane. You would need 17 50-lb buckets of sand heated to 500 F to provide the same heat as a gallon of propane. Propane, natural gas, and the other fossil fuels are highly concentrated energy sources that can be readily used where and when energy is required. That is why the world gets roughly 80% of its energy from fossil fuels and why humanity began moving away from diffuse, intermittent energy sources like wind and solar as fast as we figured out how to obtain and use fossil fuels. It is also why intermittent wind and solar augmented by battery storage struggle to be more than a niche source of energy today.
You hit the nail on the head with your assessment of the sand battery. The one you built is just too small to store enough heat to make it worthwhile. 50 lbs of sand is only about 1/2 cubic foot.
You might be interested in this, but, in our home we have some off the shelf "sand batteries" installed. We have two units, about $1500 each, they are each about the size of an old school cast iron radiator, and each with approximately 300lbs of high density and high temp bricks inside. During the night during off-peak hours they heat up the 300lbs mass to an internal temp of around 2300F and then hold it, and are programmed on a schedule to release heat during on-peak hours (when we need it) by ducting air over the bricks. Between the two units we have something like 80kWh of heat storage, they can keep the house toasty for about 2 days here in the north. We have them wired in to our panel but they could easily be wired into solar to have a totally off-grid solution.
@@texasprepperprojects I think my comment got deleted because of the link, lookup "ECOMBI" or "ecombi north america", model ECO408, we got them installed through a local HVAC company. I miss-spoke on the total storage capacity, we actually have 40kWh total with 2 units. I remember the 40kWh figure from when we did our quote but for some reason thought it was PER unit, when it was in fact combined. But still, we've had them passively keep the house very comfortable during a 2 day power outage in 0 degree weather. They actually use some predictive software to "fully charge" themselves when bad weather is on the way so you've got emergency heat ready to go.
I have to call bs as im the only company in america with a actual product close for sales for heat battery storage everyone else is still a few years away over seas theres quite a few but here in america not many close to a product to sell so please name the company and the eco408 doesnt offer even close to 40kwh of heat storage not being rude and im not angry but the problem with the renewable energy push is its filled with false claims and fake products it angers people when there scammed and turns them away from good products and well designed systems that actually work
I'm planning a 50gallon drum of sand wrapped with 5" of rockwool. The heating coils will be powered from waste wind/solar and placed throughout the drum. The heat extraction will be via air through 2x 3/4" soft copper tubes coiled through the drum. I should be able to heat it to 400/500f safety, given the rockwool.
Rockwool EXCELLENT! Heater through a hole in the flat bottom to keep wiring cooler? And three inches of closed-cell foam outside the rockwool. Post results Please!
Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
Just think for a moment about your input, it is less heat than a 300 watt incandescent light bulb produces. Then think about the heat loss throughout the whole system. You lose heat from the uninsulated sand container, the perfect heat conductor uninsulated piping, and even the uninsulated cardboard box. It was a well thought out, good test but the heat lost to the ambient air really adds up. I think most people think that a small amount of sand can hold huge amounts of heat, but they really don't even heat the small amount of sand they have. I have seen them measure the core temperature, which will be the hottest point. The only way to arrive at a ballpark sand temperature is to have an average from taking readings from the center all the way to the outside and from bottom to top. Any way, I am glad you pointed out that real heat storage requires a lot of heat input to a lot of well insulated sand. Only then can you get real usable heat output.
Funny enough, the water heater element that I used in test 1 performed better than 2 stove elements, but regardless, the heat didn't 'transfer' into my test box very well. Sure, there are lots of places that I could have improved this test build but I can't imagine getting that much more 'gain' from it
@@texasprepperprojects The basic problem (as I understand it) is how much heat one gets from electricity (with no losses). For instance, 1000 W =3412.14 BTU/hr, assuming no loss. So to provide any substantial heat, one would need a much larger electrical input and enough well insulated sand to store a lot of heat. For instance, my house has a 36,000 btu heat pump. It uses 12,283.70 watts per hour. To provide the same heat I would have to put at least 12,283.70 watts per hour into quite a large amount of sand.
Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
@@texasprepperprojects Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
@@WayneBain That sounds a bit high. Senville has a 24K BTU Heat exchanger that uses 2,500 kW/hr max. The 12K BTU uses only 910 watts/hour. If that is what you are actually using, there is an issue, or it need replaced with something more efficient.
We've all learned from your experiment. So much pseudo-science in my experience with the word "prepper", but you are a man of integrity. Your honesty is appreciated.
It's easy to over complicate these things. 300W input for 5 hours, will give 1.0kW (a small heater) output for 1.5 hours. Or 150W for 10 hours. For the 19 dark hours it's just under the equivalent of a 100W bulb. That will happily warm a well insulated incubator but you probably wouldn't notice the extra heat in a room
One thing you need to keep in mind is the heat output will start really high and decay non-linearly, so some sort of temperature regulation would be needed. 100watts per hours is an average
Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
@@BillColemanI did some calculations for water tanks years ago. The idea being two tanks one you almost freeze using winter cold collectors to cool the house during summer and one that is heated all summer to heat during winter. It was based off of duplicating a furnaces output over the season (in zone 5). I don't remember exactly what was needed but I know it was over a million gallons and quickly ended the thought experiment. A BTU is a pound of water changed one degree F and a gallon of water is about 8 pounds. If you know how many BTUs you use or can estimate it the math is pretty straight forward. I did not consider the use of a heat pump to extract heat from the tanks though, it was long ago when thermal solar was in fashon and photovoltaics were horrendously expensive and cost more energy to produce than they could ever make. I gave up on the idea as economically crazy even if you can get the local bankrupt brewery's million gallon tanks for scrap value.
I'd say your experiment was a success in that you've closed off one path and left open other paths. Wet sand holds more heat than dry sand. You need lower temperatures of the sand by spreading out the heat more. I had thought of an experiment of using expanded metal, and wet sand or clay. Layer of sand, expanded metal, layer of sand, expanded metal, layer of sand expanded metal.... and so on. In-between theses alternating layers I'd install pex tubing. My goal is not 500 degree sand in a small spot but say 75 degree sand throughout the entire thing. Tie all the layers of expanded metal to positive and negitive on the solar panels. Fill the pex pipe with a liquid then hook the pex pipe up to a radiator. Add fan and thermostat. Then give it a go.
I would try all again with your bucket inside a cardboard box. If the box is big enough, put the other box and pipes, all inside as well. Do the same test. I believe that the result will be much better.
If you use wet sand then you will need a vent to allow the steam to escape or else you will get an expulsion. And if you allow the steam to escape then the sand dries out and would need to keep adding water cooling it back down. The only other thing you could do is to make the container a pressure chamber made to withstand high pressure and install a pressure relief valve.
Sand is an excellent insulator. It doesn't easily let go of its heat. I cast aluminum in dry sand and after digging out the aluminum, the sand is still too hot to stick my hand in, a few hours later. Like the other commenter suggested, you need way more heat input. Then to extract the heat, in my uneducated opinion, I'd say you would want a steel plate with a bunch of steel rods welded to the bottom of the plate that you would shove down into the sand. Then use one of those little fans that run off heat to pull the heat out of the steel.
In your last video i gave you exactly what i did for my house to legit be heatws by the sand what i failed to mention was that i get 20kwh out from sun and i usually plug it into the wall at 120v to get the rest of the 29kwh i need total pumped into the 55 gallon drum problem really is in tge fact my oil burner system uses 650 watts only so with sand i need 29kwh and with heating oil i have to spend $20 a day in oil but also the 16kwh in electric so is sand better for heating no unless charging it up to over 700°f everyday to last the whole day threw my house now is fully sand heated and i own a 3200sq ft home so it does work i used many layers of inulation to create about r60 insulation my pipe runs threw the middle of sand though not around or over that is the fail in system everyone designs i would love to collab with you to prove this does work and that yes $2200 is alot of investment but here in new england it works perfect and if i get enough likes or comments ill make videos to show how to build it but also make it work my house is well insulated but no nore then national standard
I've been experimenting with tent heaters for years. You would be surprised how many people don't take into consideration the 3 most important factors for effectively heating a tent. They are , INSULATION, INSULATION AND INSULATION. If your tent is insulated properly, even the lowest temperature candle heaters will do a good job because you are not letting your heat escape. In many cases your own body heat is sufficient if your tent very well insulated And if your insulation is poor, even the best propane heaters are a complete waste of money, because 90% of the heat you produce will be lost through the ceiling and sides of the tent. The easiest insulation to use are cheap, large, light weight blankets filled with white synthetic polly foam. The larger the better. Then tie a plastic tarp down over it to keep the rain off and blanket dry. And heavily insulate the floor. The cold ground will very easily cause heat loss. Step 2. Get some type of fan to circulate the heat and get it off of the ceiling and down to the floor. They have small battery powered ceiling fans you can hang from the ceiling of your tent to draw the heat down to the floor. Or your make your own Step 3. Heat up a mass to absorb and evenly radiate the heat. If that is done properly you don't even need a fan to circulate the heat. The best (free) mass to use are the granite rocks that line most railroad tracks all over the USA. They are heavy and dense, and are very high on the list for heat storage. Mixing a little sand and/or copper (wire, tubes or sheets) with granite rocks would be the best option because the sand and copper can quickly absorb the heat and transfer it to the rocks much faster than the the rocks can spread the heat to other rocks. One of the easiest and most effective tent heaters I made was a 5 gallon metal bucket lined with candles covering the bottom of the bucket. The buck had 2 holes, one 3" hole cut into the side of the bucket, near the bottom, for a oxygen intake hole. A 3" metal duct tube was connected to the oxygen intake hole to bring in fresh oxygen from the outside (the oxygen tube ran from outside through a slit in the door, to the hole in the bucket) The lid to the bucket also had a small 3" hole (To off gas CO2) with a exhaust tube attached that led back out side through the same slit in the door. I put granite rocks on the top of the lid to absorb some heat. That was one of the cheapest and easiest heaters I made. Note, if you are using candles in a 5 gallon metal bucket, use short fat candles. The first time I made that heater I used tall 8" dining candles, and only the top 30% of the metal bucket radiation heat. That's because the tall candle flames were very close to the lid, which meant no candle flames at bottom of the bucket, which meant the bottom half of the metal bucket was ICE COLD. When I used short candles that were only 3-4 inches tall, the entire bucket was hot to the touch and radiated heat Because all the flames were located near the bottom of the bucket.
Now having watched your two follow ups and hearing you empathize the goal, I have a much simpler idea for you. Heat the sand. In the tent, in the room of the house, make a trough for your sleeping bag lined with tarp. Pour out the sand and fold over the tarp and lay down the sleeping bag and go to sleep.
a VERRY OLD IDEA : dig a trough , lay out your cooking fire , after the fire dies out spread the hot Coles the length of the trough and cover with original dirt /or sand. Add a breathable layer of Pine branches and sleep WARM for many hours without having to tend to a live fire .
If the heat battery is a inside room you desire to heat, there is not much problem to not insulate, because it will radiate heat day and night. That said, there is science to it, thank you for shining light into this!
Part of the experimental process is learning what does NOT work. Gave you a thumbs up for presenting your experiments and the conclusion that small scale isn't effective for your purpose. (FYI, I was hoping it worked, but you saved me the trouble. Thanks.)
Thank you! I really do agree that you shouldn't be afraid to fail, or to post failures. Like you said, I saved people time and perhaps gave some hints as to what NOT to do.
Another item that might have increased your efficicency would be to stack the elements horizontally in the center of the crucible with 2 inches or more of sand seperating. That should allow a more even distribution of heat. Another would be a proper heat sink to collect the heat from the sand and translate it into the aluminum fins. Consider the heat sink in your computer; a wide base in contact with the heat source and multiple thin fins to allow for rapid heat extraction by the air blowing over them.
I'm sorry I didn't see this 6-months ago when I was looking into this stuff. I read about the industrial scale work by Polar Night and wondered how it could be scaled domestically but when I looked at the specific heat capacity & thermal conductivity along with the surface areas of tubing (with some dodgy maths for spirals) it didn't add up. I could barely get a tonne of sand to drive 2KW on paper and my gas heater is rated at around 7KW. I think the issue you're having is getting heat into the sand and back out with such a low surface area. After messing around with different concepts (maybe the Fins were using fins) I decided the best theoretical solution I could come up with was to swap sand for course-grade gravel and loop heated air through a simple 'maze' siphoning as required. I really appreciate these videos & the work you've done and please don't stop. It's guys like you who will crack this pragmatically & BTW - adding 10 degrees for 5 hours is no mean feat. We only need the rooms at 70 degrees F.
Thank you for the reply. I'll keep testing ideas and I have some plans for parabolic heat to get the sand up higher. But it's 115F in texas right now so it will have to wait for a while ;)
Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
@@BillColeman that was the original intent of Polar Night (the Finnish company) - to provide months of thermal storage for municipal heating over winter months but they needed 100 tons of sand for 8MWh. Scaling down seems a challenge but go for it Bill.
Hey small isn't easy but it can be done. I've played in sand for for years. I've worked past pushing. Electric to heat sand. It works but in order volume and cost of electric power no matter which what or how. Keep trying you'll figure it out like. I did. Good luck
Biochemist here. The surface area in the corogated pipe that the sand is poured onto is where the heat exchange, (frozen or above 300°F) happens. This won't work in a pup tent. I had a teacher in highschool who taught a survival class (1976). When he was in the army, he would put a candle in the dirt with a tiny trench. He would peal the netting off his helmet and set that over the candle. That worked in a puptent. A cylinder 3-4ft in diameter and 12 ft tall. Three 3 inch aluminum dryer tubes, 70 ft long. Connect the 3 tubes to plenum boxes for intake and exhaust. One intake with 3 tubes and one exhaust with the other end of the 3 tubes. To the outside. The tubes will be inside the cylinder and buried in granite sand. Heavily insulate the cylinder. Bottom as well before you start.
My expectation or hope is to use 4 to 6 bags worth of sand, 200 to 300 lbs of sand, to capture power from PV panels, for the purpose of raising the ambient temp by 10 degrees so that i can save a tiny bit on heat cost during winter. I don’t expect to have an 80 degrees house, 24/7, while the weather is 24f outside. I have 4 PV panels, 230w 36v. I can add 12 more
Sand batteries work best as a Heat Exchanger. The sand captures energy from a pre existing heat source, like a Wood Furnace. A sand battery connected yo your wood furnace will remain very hot long after the wood fuel is burned away. But a Sand battery can't be the stand alone heat/energy source ....it only improves the efficiency of the existing heat/energy source.
A design for survival would be a bed over a large insulated container of sand. It’s surviving cold nights that is the most serious issue. I’d love to see you test that idea.
i lived in northern arizona, i had built a solar heating setup using 200 gallons of water. i built 2 heating panels of patio door glass and copper collectors. i circulated antifreeze from the panels to the water storage (copper pipe wound thru the water storage)... it saved me alot of money but i still had to use electric heaters. i had rust problems even though i coated the water container with the correct epoxy and correct surface preparation... one MUST use stainless steel tanks with a water storage system, but that is expensive... im living in TX now, and our house has alot of trees which block the sun. its also cloudy alot... when i get settled i would like to experiment again with a larger tank and multiple methods to heat the tank (solar, wind, fireplace and anything else i can think of)... i was here for that big Texas freeze and it was no joke. it would be nice to have a huge heat storage system
A good use might be to keep your LifePo batteries warmed up and, of course, help in the greenhouse. I am thinking of doing this. Not full house heating. For that maybe geothermal. Cool stuff.
From school physics, the relationship between heat energy input/output (dQ) and storage ability is given by dQ = m x s x dT, where m is the mass of the substance, s is its specific heat and dT is its temperature change. The specific heat of water is 4182 Joules/kg deg C, whereas sand is only 830 Joules/kg deg C. This means that a given mass of sand will warm up and cool down more quickly than water (about a factor of 5), and will not hold as much heat as water. Sand is about twice as dense as water, so we have to adjust for the mass of sand compared with water in that equation. It suggests that a bucket of water will still hold about 2.5 times as much heat as the same bucket of sand for the same temperature change. The advantage of sand is that it doesn't spill as easily and can be heated to a higher temperature (water boils at 100 C), but for practical temperatures involved in living spaces, the calculations suggest that water is a better option if it can be contained. Of course, water expands when heated, whereas sand doesn't, so that's another problematic issue to design for. Corrosion is likely to be much more of an issue with water. A good option might be along the lines of a small, portable, immersion tank without external insulation in order to lose the stored heat energy in the living space where it is needed. If energy from solar panels can be wired into the tank from outside, then so much the better. But sand has its attraction for less corrosion, static volume and is easy to obtain.
I dont know.....that graph at the end shows some useful heat being released over a 10 hour period. Seems worthwhile. I suppose it depends on expectations.
Interesting project . Appreciate your methodology , very well thought out . SAND THERMAL BATTERYs are a little explored science that in the future might have a HUGE variety of implications . Possible Moon or Mars outposts , Home greenhouse gardens , Possibly built on a large scale as an augment to Nuclear power stations utilizing coolant water ? etc . . .Keep experimenting , Thanks for your efforts . Ontario Canada .
Small input wattage and mass seems to be the issue here. Let's say you're able to heat the tent with a 1KW electric heater for about 8 hours. During those 8 hours you consumed 8KWh. That's a lot of power. So then you need to "store" this amount of power inside the mass and the mass has to be large and dense enough to retain that amount of heat to be radiated later. Just my thoughts.
From what I’ve seen, sand heat batteries, require LOTS of mass. Small scale for sand battery, means less heat, maybe only enuf to heat a tent for a bit. If using a water tank w/a convective recirculating copper tube coil in sand…the water tank can be configured to use solid fuel, or solar water heating, or even geothermal. And, it’s no risk of melting wires in sand, or difficulty replacing elements later. If I want to heat a 200 s.f. house room, built to 1970s tract house specs, I need as little as 500 watts baseboard, thermostat controlled, to keep it at about 60*F. , when outdoors is as low as 17*F. I think, if I used a simple electric 10 gal water heater, tubed to a sand battery bigger than 50# of sand…maybe stacked buckets = 100 lbs…5 hrs solar PV could warm that sand, & radiate it into the room for at least a few hours. The water could have a splitter, to provide hat water for shower, via the sand battery. The electric water heater could plug into a modest battery box w/inverter, & charge the battery from solar, wind, even an adaptor from a running car. Versatility, & ease of replacing parts. -> Keep in mind, ANY blowing on hot air or water, will very quickly cool it…you lose about 75% of the BTUs you just “paid to heat”. That’s a huge problem long covered-up by industry. Get that? Bodies sense radiant heat, somewhere around 50%. Convection is sensed something around 30%. For Blown air, the heat source MUST be sized-up, &/or run more, to compensate for that big heat losses caused by blowing it. Strive to mainly use radiant heat, & convective. Avoid blowing heat. OTH, blowing works great for cooling!
Fantastic job using data to drive decisions. I have a couple of thoughts for you: It takes more energy to go from 70 to 80 than it would to go from 50 to 60. You are also losing a lot of heat through the conduits linking your sand battery to your test box. The air circulation is a great idea to make the heat stored in the battery usable, but ducting is one of the biggest loss points for heating systems. You might get a better result with a lower store temperature & more direct venting of the heat into your test environment. Something like a direct mount from the lid of the battery to the test box keeping the circulation fans as the interface between the two.
Thank you for the thoughtful reply. I do think that there is a lot of room to 'tighten' up the system, like insulating the bucket and sealing up the joints. But I don't think, even if I did all of that, that I'd be able to get the BTU's I want to really make the difference I was hoping for.
You lost a bunch of heat through the ducting outside of the experiment. That aluminum ducting sucked a bunch of stuff off. Put the bucket in the box and try again.
@@texasprepperprojects aluminum is very good at extracting heat. That's why it's used for heat sinks. Some knife builders even use it for tempering blades. I would like to see it retried with the bucket in the box. Wouldn't you have it in the tent with you?
Here’s an idea take your sand battery experiment and get yourself a metal jug a gallon or 2 gallon size fill it full of water put a fish tank heater in it and bury that up in sand if you got your fish tank heater dialed in for the 80° water temp it should eventually heat out 50 gallon drum of sand up to 80° that should be warm enough for any house?
Lol i found this video after the build video which was posted 7 months later.... It confirmed my suspicions that this isn't viable unless you have like 500kg of sand
Insulate the sand container, then the effects will be satisfactory. Most of the heat escapes through the sheet metal of the container to the outside, which is a very large loss of energy. Greetings from Poland :)
It looks like you used concrete to line the walls of your battery. From what I've researched, concrete can hold 4-5% water content after its cured and is a fairly good conductor of heat. Would those factors cause the sand to cool faster than if a more thermally insulating material was used to hold the sand heat in? say for example plaster of paris.
Could be. I thought that the mass of the concrete would hold in the heat.. I think that it DID, but not as well as other materials would have (like rockwool)
@@texasprepperprojects Your right! Rockwool would be much better. I love the idea of using a solar panel to make a passive heater but could this thing also be used as a fireless stove for camping too? If you put a copper stick onto the bottom of a pan and then stuck the pan/stick into the super hot sand, would it conduct enough heat from the sand to heat the pan up to cooking temps? That would be great for night time cooking without a fire.
You have major inefficiencies in the element, in your uninsulated vessel, in your heat capture. I’ve got two 400W panels, a custom-wound nichrome element, a 200L steel drum inside a construction plywood box filled with rock wool insulation. It gets to around 500C on the first day, by morning is still over 300C. Over the next week all the sand gets hotter further and further from the element and the air temps are controlled by variable-speed blower. Now it’s running 24/7 and inside house is ~18C constantly. It takes some days to reach full temp, but then is sustaining. The whole thing runs straight off the panels - no controller. I’m tapping off some to run the 12v fan and wireless temperature sensors (for monitoring)
@@texasprepperprojectsNah, I'm not much of a video guy. I'm building another solar heater right now - going to pick up some aluminium tubes this week for through-sand vents. I'll take pics and post a link. I'm not convinced 900W of solar is enough, but they are all I can fit in the area the heater is going to go. I should make a project page - especially the calcs for nichrome windings.
@@texasprepperprojectsother things - I am using ESP8266s with MAX31855 thermocouple amplifiers and K-type thermocouples for monitoring. K-types are good for around 1000C so will work deep in the sand. The 8266s give decent wifi performance and the k-type thermocouples are a screw mount, so just drill an 8mm hole and wind it in to the side of the drum. I am using three - one deep in the sand inside the ring of element, one mounted on the middle of the drum and one in the insulated HVAC pipe to give my variable-speed fan a source to work from. The fan is a basic H-gate DC speed controller and everything is run from the solar panels using a cheap Chinese solar controller with USB and 12V output to a battery.
@@texasprepperprojects because it's old as time... And it's a proven way to heat an entire home for twelve hours from a tiny amount of wood. They're amazingly simple but amazingly effective.
@@texasprepperprojects th-cam.com/video/fbRi8XROncM/w-d-xo.htmlsi=m5gy_af-6jlX97VH You can cook with it too, the best part is its radiant heat, typically there is not much temperature difference between being next to the heater or upstairs away from it. There are many more benefits to it too.
@@texasprepperprojects th-cam.com/video/kHeOd8iBu6Y/w-d-xo.htmlsi=gweQLAGbYIkRcRxT In most cases you only need to burn two small fires a day to heat your entire home in the middle of a freezing winter.
Nice job with data collecting and effort. I am just curious, if you didn't circulate air, cold air from box back to sand bucket, would it be more efficient? And just to punch a few small holew on bucket to have that circulation and avoiding vacuum from pulling out heat from bucket.. maybe that is why data was bad, since sand battery was cooled down with external air from box/tent...
I think the perception of a lot of the public is that the sand acts to give back the energy of equality to that energy put in... But realistically the sand only holds and slow releases heat, the sand is a storage and immediately releases once energy input stops supplying the sand mechanism, not an active participant as the term battery would suggest... The sand is an intermediary between power input, and heat output.. akin to an older electric fires bar.. the bars an intermediary, not under any streach is that electric fires bars a battery... Get my drift... ? .. Thom in Scotland.
Yes. What I learned out of all of this is that sand Battery storage only makes sense if the heat is 'free'. Meaning you have geothermal heat coming up into it. You have a fair amount of that in Europe but we don't really have that in North America. So if you live near a volcano or hot spring it makes more sense
@@texasprepperprojects .... Yes, Iceland , Reykavik ...geothermal heating and energy to drive turbines for electricity, and geothermal heated outside swimming no pools, even to heat exchanger sea water to produce some of the world's most expensive salt, it's endless, check this out... And thank you for your reply. Thom in Scotland..
I wonder if this would work with a stainless thermal cooker (thermos and pot with handle). Heat the sand in pot, put in thermos with a copper sheet in the sand. Attached a fan at top that operates on heat.
Ever experimented with the 12 volt 50 watt ptc heating elements, it seems you can create your own electric heater with them, but use far less energy, and run it/them from solar..
if youre cooking meat on an open fire, water or sand could be heated simultaneously but what about a 12v solar panel or car battery to power a heating element
I think you're missing the point. The purpose of a sand battery is to get a useful product out of PV panels that have become cheap & plentiful while batteries remain relatively expensive per watt & per watt hour stored. It's just "A way to store energy many times cheaper than a battery". Of course you're not going to get more energy out than you put in - that would be physically impossible. The heating capability of 50lbs of sand shifting up by 150F relative to ambient is going to be trivial compared to the heating capability of 50,000lbs of house shifting up and down by 10F relative to ambient. Using a space heater to heat a small quantity of sand to heat your house isn't going to do anything different (no better, no worse) than using a space heater to heat your house, if you're examining long term effects. You want scale partially for engineering reasons, and partially to be a meaningful contribution to your home's thermal mass. The benefits of using sand are that it's inert (electrically, chemically, and phase-wise) to relatively high temperatures and a moderate thermal insulator; Stick some pipes through it to remove energy and run current through them to add energy. You want tons, if not tens or hundreds of tons, of sand, because the ability to retain heat follows a square to cube law; Heat is lost via surface area, and maximum heat storage is by volume. On a normal tank of uniform storage media, 10x the dimensions is 100x the surface area (= heat loss) and 1000x the volume. The fact that the extra volume is extra insulator improves things further. Scale is key. There's nothing saying that you can't scale it up for a single residence, but you're looking at something the size of a closet for a practical unit, not the size of a water heater or the size of a rice cooker. Using sand instead of water assumes you're going for very hot sand, because water has a 5x greater specific heat but a much lower ceiling on temperature; You get 80C out of water (20->100) and can heat sand to whatever temperature your thermal exchange pipes can survive.
What if you combined a solar stove and a sand battery? Leave it out all day, bring in at night. Thinking about directed solar array and sand batteries in commercial models. The olden times I read they used rocks in pans to put underneath beds for warmth after having them in the fireplace. Another video stated to use 5 copper plates in the sand. Said was supposed to be more effective in longer heat release. Copper is an excellent conductor of electricity. I suppose a roll of thinner copper roll could be used in a circulated method in the bucket. Another idea I was thinking, cutting ceramic tile for insulation. Cut a round one and put on bottom, top and sides. Space shuttles had tiles on it. Just some thoughts for my experiments.
Here’s an idea what if you put copper tubing or a condenser in the sand then have the fan blower air through the pipe/ condenser that way sand heats up the air in the pipe.
It still won't matter. You can't 'create' more heat where there wasn't any. The only way to make this hotter is to put more energy INTO it. The amount of hot air is still going to equal the total heat in the sand.
How much head could be generated from a gravity battery? Drop a 100 pound weight from a height of 8-10 feet … connected to a flywheel… generator… then a coil of wire to create heat as the wire is resistive load. A controlled drop of the weight using a pendulum driving the flywheel. I’m in an area that is cold in the winter with little sun. The wind blows mightily but we are not allowed wind turbines in the city. I need to create heat that is reliable without burning fossil fuels. Gravity is always present. I can easily raise a 100 pound weight to a height by grabbing a rope attached to the weight and lift my feet off the ground.
I think it has more sens to Valorize _excess energy_ that is wasted otherwise . Why not to cast a thermal mass near the gas escape tube of the motor of your car, but unclipable so you can carry the otherwise loste heat for the motor to you house when you arrive ? Other way of storage are the same as you made, but using adapted electric water heater baloon (So you can also heat a part of the house, a pool, take a shower..) as a heat battery, when the electrochemical are already full. You can also use thermochemicals to store latent heat, with basic materials like zeolite, calcium chloride by drying them, or the same material as heat pads thas can be also bought as cheap bulk. The advandage ? Storing for very long time heat from the summer to the winter, not needing any insulation.
some comments though, heat rises and you put the heating elements to the side? you should put a measure of sand on the bottom (insulation) then the first heating element (flat in the sand) then another measure of sand, the second heating element, then top it up with sand, this will insure good insulation and good transfer of heat
Well you have a bunch of things put together that is letting all your heat go. I don't think you thought about the crucible holding your heat and how much heat it did let go of. Tubing is not good at all. Maybe why they stopped selling it in some states.
you mentioned a space heater. i bought one that's oil filled. on eco mode, it's at 70, uses 600 watts of power. we were able to use our eco flow generator, not sure of the size, takes two to carry, to heat up our bedroom, that's isnt small. we were able to stay warm over night. i'm guessing because it's oil filled, it hold it's temperature for a bit making it cut back on usage. i was hoping the sand battery was going to work.
so did I.. It's just not big enough. My electric blanket pulls 300 watt hours for an 8 hour period. Try that, just buy a good, thick fleece one for $70 ish
Thanks for sharing. I am thinking water solar heater with black abs pipe stored in a vented insulated IBC tote so no relief valve needed. Have the hot water push through coils in the sand under rv or house to build passive heat flowing to IBC tank storing in water for use with a water pump to a radiator and a fan inside to replace the big buddy. Cloudy days small wood fire can work to heat water. I'm thinking that may work
Check out 'pool heaters'. Lots of people are using long coils of black pipe and small pumps to circulate water in the sun to heat it. I saw a really good test where a guy tried to heat his hot tub with this method. Short version? He didn't get much out of it. A couple of gallons coming out of the hose are hot, but then dump that into several HUNDRED gallons? Just won't make a difference. In Florida, they use solar hot water heaters on the roof for hot tubs and hot water heaters, but they are pretty big and circulate all day long. I don't think your water pipes will get hot enough to get the sand hot enough. Just spend the $75 on a buddy heater
Sure it will work but a lot of work to do, but could work. Maybe put DIY heatpipes connected to a south-side wall and let the heated water go to the isolated IBC. If you have room you could isolate the IBC with strawbales. However in winter your system will freeze so you have to get your water out before it freezes. Good luck haha!
An easy way I came up with as a pressure relief valve is to simply put a pressurized cap on let's say a 1" pipe pointing up with a hinge. On top of the cap affix a rod or weld it. Needs to be sealed like a gasket and knife edge combo but the design I created uses weights that can be placed on top of the rod coming out of the cap. You can place as much weight as you need PSI to keep the vessel pressurized. For weights you could use barbel weights or something like it so of the opening is 1" and you need 1 psi, place 1 pound on the cap. Need 100psi, place 100 lbs on the cap etc. If made well it will not stick and risk explosions and even if it did stick a little bit, it would easily break free with a little extra pressure which you could engineer into the design.
@@texasprepperprojects It all comes down to "Dwell time". With a long coil of black poly pipe out in the sun with a solar powered water pump circulating all day and the poly pipe coiled around the inside of a, say, 10,000 litre poly water tank - after a few days the temps of the water will get quite warm - a big heat exchanger if you will.
you must go back to OLD SCHOOL, really old school.. Through out the ages people lived above their farm animals in the attic so as to be heated by their heat and fermented poop heat. A person gives off heat so put one in bed with you or get a big dog. To create heat in a person just fuel with chocolate or booze and if you are lucky you will be sweating up a storm in no time.
I had a brain spark, how about building a solar powered sand heater using an old freestanding enclosed log burner or gas heater. Wiring from the Solar panels could be dropped down the chimney and the fire filled with sand., a gas fire may even have a built in fan.
Hey buddy you're inspiring me, you know the old saying if it first you don't succeed try try again, that's how Edison succeeded, also one of your commenters has a good idea with the PEX piping and expanded metal, but I'm not fully convinced about the wet sand.✌
Please watch my follow up videos. I applaud you for wanting to experiment and encourage anyone to play around with this stuff! But after messing with it for a while, I really don't think that sand batteries make sense for a home/residential situation. Now, if your house sits on a geothermal vent, then maybe. But a normal situation, there just isn't a good way to get enough heat IN, hot enough, in large enough volume, to really do anything. But, give it a shot!!!! Science is fun!
For this type of application the sand battery needs to be inside the area you are trying to heat. In your setup you are loosing too much heat to your garage!
i want to use sand because i live in northern canda if water freezes it will break my container and make a mess if sand freezes its ok antifreeze is expensive sand is cheap
I think that is partly true. The real issues is the electric to heat conversion. But even a direct solar water heater needs to be VERY large to get any net gain. I lived in Florida for a while and rooftop solar hot water heaters were common, but not small. For this to really work well, you need a large external heat source like geo thermal. Look up the hundreds of people making 'solar hot water heaters' out of black pipe and getting no where trying to heat hot tubs.
mixing things there... but yes. using thermo solar panels of the same size would make much more sense to heat some water... but at the same time, the shadow cast by having the panel on your roof would affect too, hahahaha. - Best results for the money is improving house insulation.
@@texasprepperprojects Were they using full sized water heater tanks? I remember seeing some strong a while ago about putting a 3 set of full sized water heater tanks plumbed in series into a large black box with plate glass glazing. It would be massive if you’re talking about three 50 - 80 gallon tanks getting uniformly heated too 200 F since they were deliberately absorbing as much sun as possible over a large area.
I think people need to quit thinking about 5-gallon sized sand repositories and think more along the lines of small car sized, insulated buried systems....
without insulation it will not be a battery... 200w for a couple hours, with imaginary - PERFECT insulation, once you open up to heat out, will radiate just like a 200w space heater would for those same couple hours.... so nothing. IF you have a 10kw instalation, and rather than sell your excess electricity, you want to put it in an insulated container, a big one, ... then... ... maybe... you could do something with it.
It makes no difference. It’s not getting hot enough to matter what the material is. The best I’ve found is the dusty stuff left behind when they grind sand for builders mix. After I fill my vessel, with a vibrating motor I can get about 30% more mass by shaking it down. And it’s free. Ive tried different sands and gravels and the easiest is coarse stone chip with dusty sand to infill.
Why do people keep calling it a sand battery, though? That thing is not a battery. It is simply a heater. The term battery refers to a storage medium for electric energy!
@@texasprepperprojects they are paired with solar panels; generators that use solar power. Battery is to do with electric energy not just energy. I can imagine the heated sand being used to eventually deliver electricity through various conversions. However, that is not what is being referred when they say sand battery. This has just been a case of a false terminology sticking.
I just had a thought . Just make a U shape using Coke , or a local beer not bud. cans. place over the elements and cover with sand . Leaving the tube openings above the sand
I think the small scale would be excellent for a dog house. Ours is the top half of a water tote on a pallet with old yoga/foam camping mats and a cheap rug on the floor. Door faces the direction wind never blows here. Thoughts?
I don't think so. In my opinion the best option is electric blanket. You could set up a very small solar/battery/inverter system to run a headed dog bed. I think that will be better, easier and more effective than this science project
Had you used Peltier on your sand battery??? That Peltier is is a computer electric cooler it comes in different sizes it is Tech1-1206 that is computer standard size. It goes to Tech1-1215 had you used that on your sand battery???
What about using aircrete for insulation and using copper tubing in the sand and using a 12 volt pump to water through sand in to a small radiator such as one on some motorcycle with a computer fan to circulate air the radiator
What about it? Heat is heat is heat.. Using a fan to circulate heat isn't going to make the heat any hotter. Putting a bucket of hot sand INSIDE a tent will get you the same net heat as putting a bucket of sand inside a tent with a circulator. The total net BTU's is going to even out one way or another
@@texasprepperprojects if you haven't seen this guy's channel yet I highly recommend it. @sergiyyurko8668 You can make solar mass batteries out of a number of materials. You're not wrong in your thinking, you're just wrong in how to execute it. This is something I seriously want to try. There are small steam electric generators. You get a solar collector like in Sergi's videos, and plumb it into a solar mass battery in the ground, and have it go to a steam electric generator and whatever other systems you want. Think along the lines of having 1 of these "batteries" that powers an entire neighborhood Toss in some lithium batteries for each house, and you have an off grid system, or more a mini grid system, that works all year round, and doesn't need constant sunlight
Sand holds 0.18 BTU per Lb per degree. You would need to heat about 100 lbs of sand to 500 degrees to get 7000 btus of heat. I think the issue here is scale.
@@texasprepperprojects Concrete will take in 0.33 BUT per LB per degree and hold nearly double the BTU it can hold. A 96 lb bag of concrete costs about $10. So4 bags could hold 26k btu which is 7.7 Kw of energy. To your point you'd need more solar panels to get enough power. Signature Solar in sulphur springs has some affordable priced panels but you'd probably need 1 kw of panels to charge up something in sand or cement of this scale.
@@acidtalons Thanks for the math!! I am aware of signature solar. But for all that stuff, I keep coming back to an electric blanket.. I can do a LOT with 1kw of solar
@@texasprepperprojects Absolutely, all depends on what your plan is. On our rural property we heat with LP and furnace. I've setup a solar / battery setup which is backed up by the grid and can run the furnace in the event of the grid going down. Most heating in electric in Texas from what I understand though so not likely an option.
@@acidtalons it's a mix. I'm personally on gas heat, so i could power my blower fan with solar. But others are 100% electric. It all depends on where you live
@@texasprepperprojects Sure heat is heat. But it matters to efficiency of heat transfer. Also the systems that "Work" are getting to a thousand plus degrees. If they work at all as they still may be a scam. Was doing the math yesterday and the thermal mass is all wrong.
A watt is a watt. Other than safety....... What is the difference in heat output of an open flame candle VS a clay flower pot heater?. Using the same candle? Answer...... Nothing. Carter Canada
A hand truck would be an easy way to transport a much larger weight of sand in and out of the house. And to be really simple, maybe more of solar passive method like a non-glossy black painted 55 gal metal drum heated within a green house type box all day? ;-) I lay in bed brainstorming alt energy. lmao
I am not even going to watch this.. Going to be frank with the producer. If you are not thinking in terms of swimming pool scale and upwards... waste of time. Swimming pool upwards sized, insulated thermal batteries, using techniques like ferrocement protective shells sandwhiching a fat slice of insulative foamcrete... are far better than lithium tech when all variables are considered. :) We are at the edge of collapse, gotta evolve your knowledge a magnitude faster or you will perish
A 1000-watt heater operating for one hour would provide 3412 BTU of heat. Burning a gallon of propane would provide about 91500 BTU of heat. You would have to operate the 1000-watt heater for 27 hours to get the heat produced by a gallon of propane. You would need 17 50-lb buckets of sand heated to 500 F to provide the same heat as a gallon of propane.
Propane, natural gas, and the other fossil fuels are highly concentrated energy sources that can be readily used where and when energy is required. That is why the world gets roughly 80% of its energy from fossil fuels and why humanity began moving away from diffuse, intermittent energy sources like wind and solar as fast as we figured out how to obtain and use fossil fuels. It is also why intermittent wind and solar augmented by battery storage struggle to be more than a niche source of energy today.
agreed. but i tried.
@@texasprepperprojects For a home application, you might have a look at rocket-stove mass heater.
You hit the nail on the head with your assessment of the sand battery. The one you built is just too small to store enough heat to make it worthwhile. 50 lbs of sand is only about 1/2 cubic foot.
agreed!
You might be interested in this, but, in our home we have some off the shelf "sand batteries" installed. We have two units, about $1500 each, they are each about the size of an old school cast iron radiator, and each with approximately 300lbs of high density and high temp bricks inside. During the night during off-peak hours they heat up the 300lbs mass to an internal temp of around 2300F and then hold it, and are programmed on a schedule to release heat during on-peak hours (when we need it) by ducting air over the bricks. Between the two units we have something like 80kWh of heat storage, they can keep the house toasty for about 2 days here in the north. We have them wired in to our panel but they could easily be wired into solar to have a totally off-grid solution.
Can you send a website for them???
@@texasprepperprojects I think my comment got deleted because of the link, lookup "ECOMBI" or "ecombi north america", model ECO408, we got them installed through a local HVAC company. I miss-spoke on the total storage capacity, we actually have 40kWh total with 2 units. I remember the 40kWh figure from when we did our quote but for some reason thought it was PER unit, when it was in fact combined. But still, we've had them passively keep the house very comfortable during a 2 day power outage in 0 degree weather. They actually use some predictive software to "fully charge" themselves when bad weather is on the way so you've got emergency heat ready to go.
Awesome.
How do you heat the sand?
I have to call bs as im the only company in america with a actual product close for sales for heat battery storage everyone else is still a few years away over seas theres quite a few but here in america not many close to a product to sell so please name the company and the eco408 doesnt offer even close to 40kwh of heat storage not being rude and im not angry but the problem with the renewable energy push is its filled with false claims and fake products it angers people when there scammed and turns them away from good products and well designed systems that actually work
I'm planning a 50gallon drum of sand wrapped with 5" of rockwool. The heating coils will be powered from waste wind/solar and placed throughout the drum. The heat extraction will be via air through 2x 3/4" soft copper tubes coiled through the drum. I should be able to heat it to 400/500f safety, given the rockwool.
Post a video!
Rockwool EXCELLENT! Heater through a hole in the flat bottom to keep wiring cooler? And three inches of closed-cell foam outside the rockwool. Post results Please!
Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
follow up please
instead of rock wool what about high temperature concrete
Just think for a moment about your input, it is less heat than a 300 watt incandescent light bulb produces. Then think about the heat loss throughout the whole system. You lose heat from the uninsulated sand container, the perfect heat conductor uninsulated piping, and even the uninsulated cardboard box. It was a well thought out, good test but the heat lost to the ambient air really adds up. I think most people think that a small amount of sand can hold huge amounts of heat, but they really don't even heat the small amount of sand they have. I have seen them measure the core temperature, which will be the hottest point. The only way to arrive at a ballpark sand temperature is to have an average from taking readings from the center all the way to the outside and from bottom to top. Any way, I am glad you pointed out that real heat storage requires a lot of heat input to a lot of well insulated sand. Only then can you get real usable heat output.
Funny enough, the water heater element that I used in test 1 performed better than 2 stove elements, but regardless, the heat didn't 'transfer' into my test box very well. Sure, there are lots of places that I could have improved this test build but I can't imagine getting that much more 'gain' from it
@@texasprepperprojects The basic problem (as I understand it) is how much heat one gets from electricity (with no losses). For instance, 1000 W =3412.14 BTU/hr, assuming no loss. So to provide any substantial heat, one would need a much larger electrical input and enough well insulated sand to store a lot of heat. For instance, my house has a 36,000 btu heat pump. It uses 12,283.70 watts per hour. To provide the same heat I would have to put at least 12,283.70 watts per hour into quite a large amount of sand.
Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
@@texasprepperprojects Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
@@WayneBain That sounds a bit high. Senville has a 24K BTU Heat exchanger that uses 2,500 kW/hr max. The 12K BTU uses only 910 watts/hour. If that is what you are actually using, there is an issue, or it need replaced with something more efficient.
We've all learned from your experiment. So much pseudo-science in my experience with the word "prepper", but you are a man of integrity. Your honesty is appreciated.
Thank you!
It's easy to over complicate these things. 300W input for 5 hours, will give 1.0kW (a small heater) output for 1.5 hours. Or 150W for 10 hours. For the 19 dark hours it's just under the equivalent of a 100W bulb. That will happily warm a well insulated incubator but you probably wouldn't notice the extra heat in a room
Great info!
One thing you need to keep in mind is the heat output will start really high and decay non-linearly, so some sort of temperature regulation would be needed. 100watts per hours is an average
Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
@@BillColemanI did some calculations for water tanks years ago.
The idea being two tanks one you almost freeze using winter cold collectors to cool the house during summer and one that is heated all summer to heat during winter.
It was based off of duplicating a furnaces output over the season (in zone 5).
I don't remember exactly what was needed but I know it was over a million gallons and quickly ended the thought experiment.
A BTU is a pound of water changed one degree F and a gallon of water is about 8 pounds. If you know how many BTUs you use or can estimate it the math is pretty straight forward.
I did not consider the use of a heat pump to extract heat from the tanks though, it was long ago when thermal solar was in fashon and photovoltaics were horrendously expensive and cost more energy to produce than they could ever make.
I gave up on the idea as economically crazy even if you can get the local bankrupt brewery's million gallon tanks for scrap value.
19??? OK, DRUGGIE!!!
I'd say your experiment was a success in that you've closed off one path and left open other paths.
Wet sand holds more heat than dry sand.
You need lower temperatures of the sand by spreading out the heat more.
I had thought of an experiment of using expanded metal, and wet sand or clay.
Layer of sand, expanded metal, layer of sand, expanded metal, layer of sand expanded metal.... and so on.
In-between theses alternating layers I'd install pex tubing. My goal is not 500 degree sand in a small spot but say 75 degree sand throughout the entire thing.
Tie all the layers of expanded metal to positive and negitive on the solar panels.
Fill the pex pipe with a liquid then hook the pex pipe up to a radiator. Add fan and thermostat. Then give it a go.
I would try all again with your bucket inside a cardboard box. If the box is big enough, put the other box and pipes, all inside as well. Do the same test. I believe that the result will be much better.
Check video 2
Thanks!
If you use wet sand then you will need a vent to allow the steam to escape or else you will get an expulsion. And if you allow the steam to escape then the sand dries out and would need to keep adding water cooling it back down. The only other thing you could do is to make the container a pressure chamber made to withstand high pressure and install a pressure relief valve.
@@tonyhardy-kp4osso an old hot water heater
Sand is an excellent insulator. It doesn't easily let go of its heat. I cast aluminum in dry sand and after digging out the aluminum, the sand is still too hot to stick my hand in, a few hours later. Like the other commenter suggested, you need way more heat input. Then to extract the heat, in my uneducated opinion, I'd say you would want a steel plate with a bunch of steel rods welded to the bottom of the plate that you would shove down into the sand. Then use one of those little fans that run off heat to pull the heat out of the steel.
Check out my follow up videos
In your last video i gave you exactly what i did for my house to legit be heatws by the sand what i failed to mention was that i get 20kwh out from sun and i usually plug it into the wall at 120v to get the rest of the 29kwh i need total pumped into the 55 gallon drum problem really is in tge fact my oil burner system uses 650 watts only so with sand i need 29kwh and with heating oil i have to spend $20 a day in oil but also the 16kwh in electric so is sand better for heating no unless charging it up to over 700°f everyday to last the whole day threw my house now is fully sand heated and i own a 3200sq ft home so it does work i used many layers of inulation to create about r60 insulation my pipe runs threw the middle of sand though not around or over that is the fail in system everyone designs i would love to collab with you to prove this does work and that yes $2200 is alot of investment but here in new england it works perfect and if i get enough likes or comments ill make videos to show how to build it but also make it work my house is well insulated but no nore then national standard
thanks
I've been experimenting with tent heaters for years. You would be surprised how many people don't take into consideration the 3 most important factors for effectively heating a tent.
They are , INSULATION, INSULATION AND INSULATION. If your tent is insulated properly, even the lowest temperature candle heaters will do a good job because you are not letting your heat escape. In many cases your own body heat is sufficient if your tent very well insulated
And if your insulation is poor, even the best propane heaters are a complete waste of money, because 90% of the heat you produce will be lost through the ceiling and sides of the tent.
The easiest insulation to use are cheap, large, light weight blankets filled with white synthetic polly foam. The larger the better. Then tie a plastic tarp down over it to keep the rain off and blanket dry. And heavily insulate the floor. The cold ground will very easily cause heat loss.
Step 2. Get some type of fan to circulate the heat and get it off of the ceiling and down to the floor. They have small battery powered ceiling fans you can hang from the ceiling of your tent to draw the heat down to the floor. Or your make your own
Step 3. Heat up a mass to absorb and evenly radiate the heat. If that is done properly you don't even need a fan to circulate the heat.
The best (free) mass to use are the granite rocks that line most railroad tracks all over the USA. They are heavy and dense, and are very high on the list for heat storage. Mixing a little sand and/or copper (wire, tubes or sheets) with granite rocks would be the best option because the sand and copper can quickly absorb the heat and transfer it to the rocks much faster than the the rocks can spread the heat to other rocks.
One of the easiest and most effective tent heaters I made was a 5 gallon metal bucket lined with candles covering the bottom of the bucket. The buck had 2 holes, one 3" hole cut into the side of the bucket, near the bottom, for a oxygen intake hole. A 3" metal duct tube was connected to the oxygen intake hole to bring in fresh oxygen from the outside (the oxygen tube ran from outside through a slit in the door, to the hole in the bucket)
The lid to the bucket also had a small 3" hole (To off gas CO2) with a exhaust tube attached that led back out side through the same slit in the door. I put granite rocks on the top of the lid to absorb some heat. That was one of the cheapest and easiest heaters I made.
Note, if you are using candles in a 5 gallon metal bucket, use short fat candles. The first time I made that heater I used tall 8" dining candles, and only the top 30% of the metal bucket radiation heat. That's because the tall candle flames were very close to the lid, which meant no candle flames at bottom of the bucket, which meant the bottom half of the metal bucket was ICE COLD.
When I used short candles that were only 3-4 inches tall, the entire bucket was hot to the touch and radiated heat Because all the flames were located near the bottom of the bucket.
Neat! Good info!
Now having watched your two follow ups and hearing you empathize the goal, I have a much simpler idea for you. Heat the sand. In the tent, in the room of the house, make a trough for your sleeping bag lined with tarp. Pour out the sand and fold over the tarp and lay down the sleeping bag and go to sleep.
Interesting idea!
"Wasn't buried deep enough. Spotted it right off."
a VERRY OLD IDEA : dig a trough , lay out your cooking fire , after the fire dies out spread the hot Coles the length of the trough and cover with original dirt /or sand. Add a breathable layer of Pine branches and sleep WARM for many hours without having to tend to a live fire .
If the heat battery is a inside room you desire to heat, there is not much problem to not insulate, because it will radiate heat day and night. That said, there is science to it, thank you for shining light into this!
Exactly. Check out the latest video for a revised version
Part of the experimental process is learning what does NOT work. Gave you a thumbs up for presenting your experiments and the conclusion that small scale isn't effective for your purpose. (FYI, I was hoping it worked, but you saved me the trouble. Thanks.)
Thank you! I really do agree that you shouldn't be afraid to fail, or to post failures. Like you said, I saved people time and perhaps gave some hints as to what NOT to do.
Another item that might have increased your efficicency would be to stack the elements horizontally in the center of the crucible with 2 inches or more of sand seperating.
That should allow a more even distribution of heat. Another would be a proper heat sink to collect the heat from the sand and translate it into the aluminum fins.
Consider the heat sink in your computer; a wide base in contact with the heat source and multiple thin fins to allow for rapid heat extraction by the air blowing over them.
Yup!
I'm sorry I didn't see this 6-months ago when I was looking into this stuff. I read about the industrial scale work by Polar Night and wondered how it could be scaled domestically but when I looked at the specific heat capacity & thermal conductivity along with the surface areas of tubing (with some dodgy maths for spirals) it didn't add up. I could barely get a tonne of sand to drive 2KW on paper and my gas heater is rated at around 7KW.
I think the issue you're having is getting heat into the sand and back out with such a low surface area. After messing around with different concepts (maybe the Fins were using fins) I decided the best theoretical solution I could come up with was to swap sand for course-grade gravel and loop heated air through a simple 'maze' siphoning as required.
I really appreciate these videos & the work you've done and please don't stop. It's guys like you who will crack this pragmatically & BTW - adding 10 degrees for 5 hours is no mean feat. We only need the rooms at 70 degrees F.
Thank you for the reply. I'll keep testing ideas and I have some plans for parabolic heat to get the sand up higher. But it's 115F in texas right now so it will have to wait for a while ;)
@@texasprepperprojects so I hear, you'll get more inspiration in the winter I guess.
Wondering about the feasibility of seasonal input and storage. That is to say, heat the sand during the summer months and use the heat to supplement furnace during early winter.
@@BillColeman that was the original intent of Polar Night (the Finnish company) - to provide months of thermal storage for municipal heating over winter months but they needed 100 tons of sand for 8MWh.
Scaling down seems a challenge but go for it Bill.
@@BillColeman It's all about mass. And you need a LOT of it. Like, tons. Geothermal air heating makes a lot more sense. I wish I could try it
You could use cast iron, in which the heat would radiate more evenly
Check out video 3
Hey small isn't easy but it can be done. I've played in sand for for years. I've worked past pushing. Electric to heat sand. It works but in order volume and cost of electric power no matter which what or how. Keep trying you'll figure it out like. I did. Good luck
Right on
Evidence of an efficient system or it didn't happen ;)
Biochemist here. The surface area in the corogated pipe that the sand is poured onto is where the heat exchange, (frozen or above 300°F) happens.
This won't work in a pup tent.
I had a teacher in highschool who taught a survival class (1976). When he was in the army, he would put a candle in the dirt with a tiny trench. He would peal the netting off his helmet and set that over the candle. That worked in a puptent.
A cylinder 3-4ft in diameter and 12 ft tall. Three 3 inch aluminum dryer tubes, 70 ft long.
Connect the 3 tubes to plenum boxes for intake and exhaust. One intake with 3 tubes and one exhaust with the other end of the 3 tubes. To the outside.
The tubes will be inside the cylinder and buried in granite sand.
Heavily insulate the cylinder.
Bottom as well before you start.
Ever tried it?
My expectation or hope is to use 4 to 6 bags worth of sand, 200 to 300 lbs of sand, to capture power from PV panels, for the purpose of raising the ambient temp by 10 degrees so that i can save a tiny bit on heat cost during winter.
I don’t expect to have an 80 degrees house, 24/7, while the weather is 24f outside.
I have 4 PV panels, 230w 36v. I can add 12 more
Just please do the math on the resistance like I show in the other videos. Probably thr best thing is to link them all and get voltage up to 120v dc
Sand batteries work best as a Heat Exchanger. The sand captures energy from a pre existing heat source, like a Wood Furnace.
A sand battery connected yo your wood furnace will remain very hot long after the wood fuel is burned away. But a Sand battery can't be the stand alone heat/energy source ....it only improves the efficiency of the existing heat/energy source.
Or as a dump.load
A design for survival would be a bed over a large insulated container of sand. It’s surviving cold nights that is the most serious issue. I’d love to see you test that idea.
Check out all of my other sand battery vids
@@texasprepperprojects I will. Cheers
i lived in northern arizona, i had built a solar heating setup using 200 gallons of water. i built 2 heating panels of patio door glass and copper collectors. i circulated antifreeze from the panels to the water storage (copper pipe wound thru the water storage)... it saved me alot of money but i still had to use electric heaters. i had rust problems even though i coated the water container with the correct epoxy and correct surface preparation... one MUST use stainless steel tanks with a water storage system, but that is expensive... im living in TX now, and our house has alot of trees which block the sun. its also cloudy alot... when i get settled i would like to experiment again with a larger tank and multiple methods to heat the tank (solar, wind, fireplace and anything else i can think of)... i was here for that big Texas freeze and it was no joke. it would be nice to have a huge heat storage system
nice!
A good use might be to keep your LifePo batteries warmed up and, of course, help in the greenhouse. I am thinking of doing this. Not full house heating. For that maybe geothermal. Cool stuff.
Thanks!
From school physics, the relationship between heat energy input/output (dQ) and storage ability is given by dQ = m x s x dT, where m is the mass of the substance, s is its specific heat and dT is its temperature change. The specific heat of water is 4182 Joules/kg deg C, whereas sand is only 830 Joules/kg deg C. This means that a given mass of sand will warm up and cool down more quickly than water (about a factor of 5), and will not hold as much heat as water.
Sand is about twice as dense as water, so we have to adjust for the mass of sand compared with water in that equation. It suggests that a bucket of water will still hold about 2.5 times as much heat as the same bucket of sand for the same temperature change.
The advantage of sand is that it doesn't spill as easily and can be heated to a higher temperature (water boils at 100 C), but for practical temperatures involved in living spaces, the calculations suggest that water is a better option if it can be contained. Of course, water expands when heated, whereas sand doesn't, so that's another problematic issue to design for. Corrosion is likely to be much more of an issue with water.
A good option might be along the lines of a small, portable, immersion tank without external insulation in order to lose the stored heat energy in the living space where it is needed. If energy from solar panels can be wired into the tank from outside, then so much the better. But sand has its attraction for less corrosion, static volume and is easy to obtain.
Thanks
I dont know.....that graph at the end shows some useful heat being released over a 10 hour period. Seems worthwhile. I suppose it depends on expectations.
What you see at the tail end is the ambient air in the garage.
Interesting project . Appreciate your methodology , very well thought out . SAND THERMAL BATTERYs are a little explored science that in the future might have a HUGE variety of implications . Possible Moon or Mars outposts , Home greenhouse gardens , Possibly built on a large scale as an augment to Nuclear power stations utilizing coolant water ? etc . . .Keep experimenting , Thanks for your efforts . Ontario Canada .
Thank you!
Small input wattage and mass seems to be the issue here. Let's say you're able to heat the tent with a 1KW electric heater for about 8 hours. During those 8 hours you consumed 8KWh. That's a lot of power. So then you need to "store" this amount of power inside the mass and the mass has to be large and dense enough to retain that amount of heat to be radiated later. Just my thoughts.
Agreed. Fun experiment but not practical at small scales
From what I’ve seen, sand heat batteries, require LOTS of mass.
Small scale for sand battery, means less heat, maybe only enuf to heat a tent for a bit.
If using a water tank w/a convective recirculating copper tube coil in sand…the water tank can be configured to use solid fuel, or solar water heating, or even geothermal. And, it’s no risk of melting wires in sand, or difficulty replacing elements later.
If I want to heat a 200 s.f. house room, built to 1970s tract house specs, I need as little as 500 watts baseboard, thermostat controlled, to keep it at about 60*F. , when outdoors is as low as 17*F.
I think, if I used a simple electric 10 gal water heater, tubed to a sand battery bigger than 50# of sand…maybe stacked buckets = 100 lbs…5 hrs solar PV could warm that sand, & radiate it into the room for at least a few hours. The water could have a splitter, to provide hat water for shower, via the sand battery.
The electric water heater could plug into a modest battery box w/inverter, & charge the battery from solar, wind, even an adaptor from a running car. Versatility, & ease of replacing parts.
-> Keep in mind, ANY blowing on hot air or water, will very quickly cool it…you lose about 75% of the BTUs you just “paid to heat”. That’s a huge problem long covered-up by industry. Get that?
Bodies sense radiant heat, somewhere around 50%. Convection is sensed something around 30%. For Blown air, the heat source MUST be sized-up, &/or run more, to compensate for that big heat losses caused by blowing it.
Strive to mainly use radiant heat, & convective. Avoid blowing heat.
OTH, blowing works great for cooling!
Check my other videos for testing
Fantastic job using data to drive decisions. I have a couple of thoughts for you:
It takes more energy to go from 70 to 80 than it would to go from 50 to 60. You are also losing a lot of heat through the conduits linking your sand battery to your test box. The air circulation is a great idea to make the heat stored in the battery usable, but ducting is one of the biggest loss points for heating systems.
You might get a better result with a lower store temperature & more direct venting of the heat into your test environment. Something like a direct mount from the lid of the battery to the test box keeping the circulation fans as the interface between the two.
Thank you for the thoughtful reply. I do think that there is a lot of room to 'tighten' up the system, like insulating the bucket and sealing up the joints. But I don't think, even if I did all of that, that I'd be able to get the BTU's I want to really make the difference I was hoping for.
You lost a bunch of heat through the ducting outside of the experiment. That aluminum ducting sucked a bunch of stuff off. Put the bucket in the box and try again.
I don't think I lost that much from the duct.
@@texasprepperprojects aluminum is very good at extracting heat. That's why it's used for heat sinks. Some knife builders even use it for tempering blades. I would like to see it retried with the bucket in the box. Wouldn't you have it in the tent with you?
@@battleaxefabandmachine in a perfect world, yes
Thank you 🙏🏽
You are so welcome
اسعدك الله في الدنيا والآخرة..❤
Thanks
Here’s an idea take your sand battery experiment and get yourself a metal jug a gallon or 2 gallon size fill it full of water put a fish tank heater in it and bury that up in sand if you got your fish tank heater dialed in for the 80° water temp it should eventually heat out 50 gallon drum of sand up to 80° that should be warm enough for any house?
No it won't. The heater element i used gets far hotter than that
Lol i found this video after the build video which was posted 7 months later....
It confirmed my suspicions that this isn't viable unless you have like 500kg of sand
agreed
You need a lot more watts to make it work. I am test a sand battery today with 3500 watts of electricity using two waster heater elements.
I am running a tiny system here.
Have you considered powering the sand battery with the trapped heat from a greenhouse?
Nope
Insulate the sand container, then the effects will be satisfactory. Most of the heat escapes through the sheet metal of the container to the outside, which is a very large loss of energy. Greetings from Poland :)
The container had a concrete liner
It looks like you used concrete to line the walls of your battery. From what I've researched, concrete can hold 4-5% water content after its cured and is a fairly good conductor of heat. Would those factors cause the sand to cool faster than if a more thermally insulating material was used to hold the sand heat in? say for example plaster of paris.
Could be. I thought that the mass of the concrete would hold in the heat.. I think that it DID, but not as well as other materials would have (like rockwool)
@@texasprepperprojects Your right! Rockwool would be much better. I love the idea of using a solar panel to make a passive heater but could this thing also be used as a fireless stove for camping too? If you put a copper stick onto the bottom of a pan and then stuck the pan/stick into the super hot sand, would it conduct enough heat from the sand to heat the pan up to cooking temps? That would be great for night time cooking without a fire.
You have major inefficiencies in the element, in your uninsulated vessel, in your heat capture. I’ve got two 400W panels, a custom-wound nichrome element, a 200L steel drum inside a construction plywood box filled with rock wool insulation. It gets to around 500C on the first day, by morning is still over 300C. Over the next week all the sand gets hotter further and further from the element and the air temps are controlled by variable-speed blower. Now it’s running 24/7 and inside house is ~18C constantly. It takes some days to reach full temp, but then is sustaining. The whole thing runs straight off the panels - no controller. I’m tapping off some to run the 12v fan and wireless temperature sensors (for monitoring)
I sure do. Do you have a video showing your system??
@@texasprepperprojectsNah, I'm not much of a video guy. I'm building another solar heater right now - going to pick up some aluminium tubes this week for through-sand vents. I'll take pics and post a link. I'm not convinced 900W of solar is enough, but they are all I can fit in the area the heater is going to go. I should make a project page - especially the calcs for nichrome windings.
@@texasprepperprojectsother things - I am using ESP8266s with MAX31855 thermocouple amplifiers and K-type thermocouples for monitoring. K-types are good for around 1000C so will work deep in the sand. The 8266s give decent wifi performance and the k-type thermocouples are a screw mount, so just drill an 8mm hole and wind it in to the side of the drum. I am using three - one deep in the sand inside the ring of element, one mounted on the middle of the drum and one in the insulated HVAC pipe to give my variable-speed fan a source to work from. The fan is a basic H-gate DC speed controller and everything is run from the solar panels using a cheap Chinese solar controller with USB and 12V output to a battery.
Heat powered stove fan will do the trick once you heat up the sand.
how do you figure that?
@@texasprepperprojects Because other projects show it in action: heat powered fan sand, th-cam.com/video/n8emwEairpM/w-d-xo.html - as an example
The masonry heater is where it's at...
And why is that
@@texasprepperprojects because it's old as time... And it's a proven way to heat an entire home for twelve hours from a tiny amount of wood. They're amazingly simple but amazingly effective.
@@texasprepperprojects
th-cam.com/video/fbRi8XROncM/w-d-xo.htmlsi=m5gy_af-6jlX97VH
You can cook with it too, the best part is its radiant heat, typically there is not much temperature difference between being next to the heater or upstairs away from it. There are many more benefits to it too.
@@texasprepperprojects th-cam.com/video/kHeOd8iBu6Y/w-d-xo.htmlsi=gweQLAGbYIkRcRxT
In most cases you only need to burn two small fires a day to heat your entire home in the middle of a freezing winter.
sure@@MoonSpyStudios if you live in 500sq feet
Nice job with data collecting and effort. I am just curious, if you didn't circulate air, cold air from box back to sand bucket, would it be more efficient? And just to punch a few small holew on bucket to have that circulation and avoiding vacuum from pulling out heat from bucket.. maybe that is why data was bad, since sand battery was cooled down with external air from box/tent...
Eh could be. Check out my newest video for more specifics about the setup. It all depends on where your sand is, in relation to the air space
Cutting a round hole in cardboard? We used to run a hand power drill backward with a hole saw to put speakers in automobile doors.
neat idea!
I think the perception of a lot of the public is that the sand acts to give back the energy of equality to that energy put in... But realistically the sand only holds and slow releases heat, the sand is a storage and immediately releases once energy input stops supplying the sand mechanism, not an active participant as the term battery would suggest... The sand is an intermediary between power input, and heat output.. akin to an older electric fires bar.. the bars an intermediary, not under any streach is that electric fires bars a battery...
Get my drift... ? ..
Thom in Scotland.
Yes. What I learned out of all of this is that sand Battery storage only makes sense if the heat is 'free'. Meaning you have geothermal heat coming up into it. You have a fair amount of that in Europe but we don't really have that in North America. So if you live near a volcano or hot spring it makes more sense
@@texasprepperprojects .... Yes, Iceland , Reykavik ...geothermal heating and energy to drive turbines for electricity, and geothermal heated outside swimming no pools, even to heat exchanger sea water to produce some of the world's most expensive salt, it's endless, check this out... And thank you for your reply.
Thom in Scotland..
I wonder if this would work with a stainless thermal cooker (thermos and pot with handle). Heat the sand in pot, put in thermos with a copper sheet in the sand. Attached a fan at top that operates on heat.
K
Çast iron lid from a Dutch oven, maybe 🤔
Maybe. Check out video 3
Ever experimented with the 12 volt 50 watt ptc heating elements, it seems you can create your own electric heater with them, but use far less energy, and run it/them from solar..
That is literally not possible. A 50 watt ptc puts out the same heat as a 50w water heater element
if youre cooking meat on an open fire, water or sand could be heated simultaneously but what about a 12v solar panel or car battery to power a heating element
Not enough voltage. Watch the other videos in the series.
How about switching from air to water for heat transfer from sand using coper pipe coils
Won't matter. Heat is heat. You can't create extra heat from nothing. Check out my other videos in the series
use protection around all connection from the sand out. If possible,, element needs the bottom half of container.
Thanks
I think you're missing the point. The purpose of a sand battery is to get a useful product out of PV panels that have become cheap & plentiful while batteries remain relatively expensive per watt & per watt hour stored. It's just "A way to store energy many times cheaper than a battery". Of course you're not going to get more energy out than you put in - that would be physically impossible.
The heating capability of 50lbs of sand shifting up by 150F relative to ambient is going to be trivial compared to the heating capability of 50,000lbs of house shifting up and down by 10F relative to ambient. Using a space heater to heat a small quantity of sand to heat your house isn't going to do anything different (no better, no worse) than using a space heater to heat your house, if you're examining long term effects. You want scale partially for engineering reasons, and partially to be a meaningful contribution to your home's thermal mass.
The benefits of using sand are that it's inert (electrically, chemically, and phase-wise) to relatively high temperatures and a moderate thermal insulator; Stick some pipes through it to remove energy and run current through them to add energy. You want tons, if not tens or hundreds of tons, of sand, because the ability to retain heat follows a square to cube law; Heat is lost via surface area, and maximum heat storage is by volume. On a normal tank of uniform storage media, 10x the dimensions is 100x the surface area (= heat loss) and 1000x the volume. The fact that the extra volume is extra insulator improves things further. Scale is key. There's nothing saying that you can't scale it up for a single residence, but you're looking at something the size of a closet for a practical unit, not the size of a water heater or the size of a rice cooker.
Using sand instead of water assumes you're going for very hot sand, because water has a 5x greater specific heat but a much lower ceiling on temperature; You get 80C out of water (20->100) and can heat sand to whatever temperature your thermal exchange pipes can survive.
Check my other videos
What if you combined a solar stove and a sand battery? Leave it out all day, bring in at night. Thinking about directed solar array and sand batteries in commercial models. The olden times I read they used rocks in pans to put underneath beds for warmth after having them in the fireplace.
Another video stated to use 5 copper plates in the sand. Said was supposed to be more effective in longer heat release. Copper is an excellent conductor of electricity. I suppose a roll of thinner copper roll could be used in a circulated method in the bucket.
Another idea I was thinking, cutting ceramic tile for insulation. Cut a round one and put on bottom, top and sides. Space shuttles had tiles on it.
Just some thoughts for my experiments.
check my follow up videos for some of these ideas
Fossil fuel bonfires? How do you make those?
Wood
@@texasprepperprojects when did wood become a fossil fuel?
did you compare sand to water?
Yes look at my other videos
Here’s an idea what if you put copper tubing or a condenser in the sand then have the fan blower air through the pipe/ condenser that way sand heats up the air in the pipe.
It still won't matter. You can't 'create' more heat where there wasn't any. The only way to make this hotter is to put more energy INTO it. The amount of hot air is still going to equal the total heat in the sand.
How much head could be generated from a gravity battery? Drop a 100 pound weight from a height of 8-10 feet … connected to a flywheel… generator… then a coil of wire to create heat as the wire is resistive load. A controlled drop of the weight using a pendulum driving the flywheel. I’m in an area that is cold in the winter with little sun. The wind blows mightily but we are not allowed wind turbines in the city. I need to create heat that is reliable without burning fossil fuels. Gravity is always present. I can easily raise a 100 pound weight to a height by grabbing a rope attached to the weight and lift my feet off the ground.
Sounds a lot more complex than it's worth. Just use solar. A mechanical battery like that only makes sense if you have a mechanical way to lift it
I think it has more sens to Valorize _excess energy_ that is wasted otherwise . Why not to cast a thermal mass near the gas escape tube of the motor of your car, but unclipable so you can carry the otherwise loste heat for the motor to you house when you arrive ?
Other way of storage are the same as you made, but using adapted electric water heater baloon (So you can also heat a part of the house, a pool, take a shower..) as a heat battery, when the electrochemical are already full. You can also use thermochemicals to store latent heat, with basic materials like zeolite, calcium chloride by drying them, or the same material as heat pads thas can be also bought as cheap bulk. The advandage ? Storing for very long time heat from the summer to the winter, not needing any insulation.
perhaps
some comments though, heat rises and you put the heating elements to the side?
you should put a measure of sand on the bottom (insulation) then the first heating element (flat in the sand) then another measure of sand, the second heating element, then top it up with sand, this will insure good insulation and good transfer of heat
Thanks
Well you have a bunch of things put together that is letting all your heat go. I don't think you thought about the crucible holding your heat and how much heat it did let go of. Tubing is not good at all. Maybe why they stopped selling it in some states.
maybe
@@texasprepperprojects no maybe about it. Have a great day
It could be interesting just with a box big enough to put over the whole crucible.
could be@@phillipErskine-jk1jt
Good on you for having a go. Pity it didn't work out but it was very interesting to watch. 👍
Thanks 👍
you mentioned a space heater. i bought one that's oil filled. on eco mode, it's at 70, uses 600 watts of power. we were able to use our eco flow generator, not sure of the size, takes two to carry, to heat up our bedroom, that's isnt small. we were able to stay warm over night. i'm guessing because it's oil filled, it hold it's temperature for a bit making it cut back on usage. i was hoping the sand battery was going to work.
so did I.. It's just not big enough. My electric blanket pulls 300 watt hours for an 8 hour period. Try that, just buy a good, thick fleece one for $70 ish
Thanks for sharing. I am thinking water solar heater with black abs pipe stored in a vented insulated IBC tote so no relief valve needed. Have the hot water push through coils in the sand under rv or house to build passive heat flowing to IBC tank storing in water for use with a water pump to a radiator and a fan inside to replace the big buddy. Cloudy days small wood fire can work to heat water. I'm thinking that may work
Check out 'pool heaters'. Lots of people are using long coils of black pipe and small pumps to circulate water in the sun to heat it. I saw a really good test where a guy tried to heat his hot tub with this method. Short version? He didn't get much out of it. A couple of gallons coming out of the hose are hot, but then dump that into several HUNDRED gallons? Just won't make a difference. In Florida, they use solar hot water heaters on the roof for hot tubs and hot water heaters, but they are pretty big and circulate all day long. I don't think your water pipes will get hot enough to get the sand hot enough. Just spend the $75 on a buddy heater
Sure it will work but a lot of work to do, but could work. Maybe put DIY heatpipes connected to a south-side wall and let the heated water go to the isolated IBC. If you have room you could isolate the IBC with strawbales. However in winter your system will freeze so you have to get your water out before it freezes. Good luck haha!
An easy way I came up with as a pressure relief valve is to simply put a pressurized cap on let's say a 1" pipe pointing up with a hinge. On top of the cap affix a rod or weld it. Needs to be sealed like a gasket and knife edge combo but the design I created uses weights that can be placed on top of the rod coming out of the cap. You can place as much weight as you need PSI to keep the vessel pressurized. For weights you could use barbel weights or something like it so of the opening is 1" and you need 1 psi, place 1 pound on the cap. Need 100psi, place 100 lbs on the cap etc. If made well it will not stick and risk explosions and even if it did stick a little bit, it would easily break free with a little extra pressure which you could engineer into the design.
@@hansscholte5472 I mostly only get surface frost so if buried IBC is fine just make sure to drain rest of system to the tank. Thanks for your input.
@@texasprepperprojects It all comes down to "Dwell time". With a long coil of black poly pipe out in the sun with a solar powered water pump circulating all day and the poly pipe coiled around the inside of a, say, 10,000 litre poly water tank - after a few days the temps of the water will get quite warm - a big heat exchanger if you will.
you must go back to OLD SCHOOL, really old school.. Through out the ages people lived above their farm animals in the attic so as to be heated by their heat and fermented poop heat. A person gives off heat so put one in bed with you or get a big dog. To create heat in a person just fuel with chocolate or booze and if you are lucky you will be sweating up a storm in no time.
thanks
I had a brain spark, how about building a solar powered sand heater using an old freestanding enclosed log burner or gas heater. Wiring from the Solar panels could be dropped down the chimney and the fire filled with sand., a gas fire may even have a built in fan.
Check video 3. Still not going to cheat thermodynamics
Hey buddy you're inspiring me, you know the old saying if it first you don't succeed try try again, that's how Edison succeeded, also one of your commenters has a good idea with the PEX piping and expanded metal, but I'm not fully convinced about the wet sand.✌
Please watch my follow up videos. I applaud you for wanting to experiment and encourage anyone to play around with this stuff! But after messing with it for a while, I really don't think that sand batteries make sense for a home/residential situation. Now, if your house sits on a geothermal vent, then maybe. But a normal situation, there just isn't a good way to get enough heat IN, hot enough, in large enough volume, to really do anything. But, give it a shot!!!! Science is fun!
For this type of application the sand battery needs to be inside the area you are trying to heat. In your setup you are loosing too much heat to your garage!
Did you watch the video? It goes into a box
Thanks for showing everything you learned from all this work.
You are welcome
i want to use sand because i live in northern canda if water freezes it will break my container and make a mess if sand freezes its ok
antifreeze is expensive sand is cheap
Try it!
I think there is no escaping the fact that solar eletric is around 15 to 18% efficient where solar heaters for water is more than 50%.
I think that is partly true. The real issues is the electric to heat conversion. But even a direct solar water heater needs to be VERY large to get any net gain. I lived in Florida for a while and rooftop solar hot water heaters were common, but not small. For this to really work well, you need a large external heat source like geo thermal. Look up the hundreds of people making 'solar hot water heaters' out of black pipe and getting no where trying to heat hot tubs.
mixing things there... but yes. using thermo solar panels of the same size would make much more sense to heat some water... but at the same time, the shadow cast by having the panel on your roof would affect too, hahahaha. - Best results for the money is improving house insulation.
@@texasprepperprojects Were they using full sized water heater tanks?
I remember seeing some strong a while ago about putting a 3 set of full sized water heater tanks plumbed in series into a large black box with plate glass glazing. It would be massive if you’re talking about three 50 - 80 gallon tanks getting uniformly heated too 200 F since they were deliberately absorbing as much sun as possible over a large area.
I think people need to quit thinking about 5-gallon sized sand repositories and think more along the lines of small car sized, insulated buried systems....
without insulation it will not be a battery... 200w for a couple hours, with imaginary - PERFECT insulation, once you open up to heat out, will radiate just like a 200w space heater would for those same couple hours.... so nothing. IF you have a 10kw instalation, and rather than sell your excess electricity, you want to put it in an insulated container, a big one, ... then... ... maybe... you could do something with it.
agreed its not big enough to be worth it
I’m suggesting that it matters very much what the sand is made of. I believe it needs to be an extremely high quartz content
Cool
It makes no difference. It’s not getting hot enough to matter what the material is. The best I’ve found is the dusty stuff left behind when they grind sand for builders mix. After I fill my vessel, with a vibrating motor I can get about 30% more mass by shaking it down. And it’s free. Ive tried different sands and gravels and the easiest is coarse stone chip with dusty sand to infill.
Why do people keep calling it a sand battery, though? That thing is not a battery. It is simply a heater. The term battery refers to a storage medium for electric energy!
The Sand is 'storing' the heat...like...a...battery??
@@texasprepperprojects I know that's the intended reference but it is very misleading.
Why do people call power stations 'solar generators'?
@@texasprepperprojects they are paired with solar panels; generators that use solar power.
Battery is to do with electric energy not just energy. I can imagine the heated sand being used to eventually deliver electricity through various conversions. However, that is not what is being referred when they say sand battery.
This has just been a case of a false terminology sticking.
True
Try ceramic heating or heater storage bricks
Check out the other videos in the series
I just had a thought . Just make a U shape using Coke , or a local beer not bud. cans.
place over the elements and cover with sand . Leaving the tube openings above the sand
and what would the purpose be?
Sounds gay,
The purpose doesn’t matter, just enjoy drinking the beer 😃
Can you show how you wired up to the element. I now the solar panel are red positive and black negative.?
On the element it does not matter. Ac had no polarity
I think the small scale would be excellent for a dog house. Ours is the top half of a water tote on a pallet with old yoga/foam camping mats and a cheap rug on the floor. Door faces the direction wind never blows here. Thoughts?
I don't think so. In my opinion the best option is electric blanket. You could set up a very small solar/battery/inverter system to run a headed dog bed. I think that will be better, easier and more effective than this science project
Have you thought about a hybrid solar water + solar electric to create a passive system with other materials?
considered it. Stay tuned to an upcoming video on this topic......
Had you used Peltier on your sand battery??? That Peltier is is a computer electric cooler it comes in different sizes it is Tech1-1206 that is computer standard size. It goes to Tech1-1215 had you used that on your sand battery???
I was going to use a TEC to power the mini 12v dc fan.. if I'd had better results
What about using aircrete for insulation and using copper tubing in the sand and using a 12 volt pump to water through sand in to a small radiator such as one on some motorcycle with a computer fan to circulate air the radiator
What about it? Heat is heat is heat.. Using a fan to circulate heat isn't going to make the heat any hotter. Putting a bucket of hot sand INSIDE a tent will get you the same net heat as putting a bucket of sand inside a tent with a circulator. The total net BTU's is going to even out one way or another
Alcohol si fuel...transport, stable, ease to make...motor is the problem...
Ok
dude..... sand batteries need to be big. like metric tonnes of sand big
Agreed. I know better now
@@texasprepperprojects if you haven't seen this guy's channel yet I highly recommend it.
@sergiyyurko8668
You can make solar mass batteries out of a number of materials. You're not wrong in your thinking, you're just wrong in how to execute it.
This is something I seriously want to try. There are small steam electric generators.
You get a solar collector like in Sergi's videos, and plumb it into a solar mass battery in the ground, and have it go to a steam electric generator and whatever other systems you want.
Think along the lines of having 1 of these "batteries" that powers an entire neighborhood
Toss in some lithium batteries for each house, and you have an off grid system, or more a mini grid system, that works all year round, and doesn't need constant sunlight
Sand holds 0.18 BTU per Lb per degree. You would need to heat about 100 lbs of sand to 500 degrees to get 7000 btus of heat. I think the issue here is scale.
Good math!!
@@texasprepperprojects Concrete will take in 0.33 BUT per LB per degree and hold nearly double the BTU it can hold. A 96 lb bag of concrete costs about $10. So4 bags could hold 26k btu which is 7.7 Kw of energy. To your point you'd need more solar panels to get enough power. Signature Solar in sulphur springs has some affordable priced panels but you'd probably need 1 kw of panels to charge up something in sand or cement of this scale.
@@acidtalons Thanks for the math!! I am aware of signature solar. But for all that stuff, I keep coming back to an electric blanket.. I can do a LOT with 1kw of solar
@@texasprepperprojects Absolutely, all depends on what your plan is. On our rural property we heat with LP and furnace. I've setup a solar / battery setup which is backed up by the grid and can run the furnace in the event of the grid going down. Most heating in electric in Texas from what I understand though so not likely an option.
@@acidtalons it's a mix. I'm personally on gas heat, so i could power my blower fan with solar. But others are 100% electric. It all depends on where you live
What about a cast iron lid with cfm wood burning stove fans
Won't make a difference. Check out my follow up videos
This has a fatal flaw IMHO. How you are heating the sand is good. but the extraction is the problem. you need pipes in the sand to carry the heat out.
why does that matter? Heat is heat is heat.
@@texasprepperprojects Sure heat is heat. But it matters to efficiency of heat transfer. Also the systems that "Work" are getting to a thousand plus degrees. If they work at all as they still may be a scam. Was doing the math yesterday and the thermal mass is all wrong.
I noticed you were working in shorts and t shirt it must have worked
ah, Texas.
A watt is a watt. Other than safety....... What is the difference in heat output of an open flame candle VS a clay flower pot heater?. Using the same candle? Answer...... Nothing. Carter Canada
Correct which is why candle and clay pot heaters are a huge scam joke
What about wet sand ?
i dont know
A hand truck would be an easy way to transport a much larger weight of sand in and out of the house. And to be really simple, maybe more of solar passive method like a non-glossy black painted 55 gal metal drum heated within a green house type box all day? ;-) I lay in bed brainstorming alt energy. lmao
I'm going to try the sun heating once the sun comes out.. but I'm skeptical it will go up that much. Fun to try tho
I am not even going to watch this..
Going to be frank with the producer. If you are not thinking in terms of swimming pool scale and upwards... waste of time.
Swimming pool upwards sized, insulated thermal batteries, using techniques like ferrocement protective shells sandwhiching a fat slice of insulative foamcrete... are far better than lithium tech when all variables are considered. :)
We are at the edge of collapse, gotta evolve your knowledge a magnitude faster or you will perish
So helpful thanks
A lot of words
it is
Get a natural gas or propane STOVE.
thanks
"Free" energy. Really? Isaac Newton called, he wants his laws back.
Solar energy is free
Bravo mate, been looking into small greenhouse night battery radiant heat.
Thanks!