@judoyodan it is a dark inner surface with a vacuum around it. Vacuums do not transfer heat well, they are a vary good insulator. Sunlight penetrates the clear outer glass and heats the black coating delivering heat to the water. Heat can only escape through the top. This builds temperature fast. This is a typical glass thermos but clear on the outside vs silver.
@GREENPOWERSCIENCE this is the same principle as the solar farms that use a field of adjustable mirrors to superheat a collector to boil water for electricity production, just on a much much smaller and more practical scale. I like!
Dan ... Just thought of a couple of things ... 1. The Center hold down spar? You make it out of wood sooooo if you used a tensioned wire there.. say 12 Gauge Copper Wire? (no insulator) tensioned by by a bolt, two nuts, and two washers on the underside on the spar on the reverse side.. you could have less possible light lost and likely it would be cheaper as all the items I just mentioned can be sourced from objects that get thrown out everyday. 2. If you wanted to use this as a boiler for a steam turbine I would run a water inlet and outlet hole into the umm boiler unit... have a valve that allows the steam out for the outlet... through your turbine and then to your water tank to pressurize it to sort of force feed the boiler fresh water... also I would insulate the top length of the boiler unit as ummm while it is a vacuum thermos type deal.. it well honestly you are likely losing more heat out of the side not being hit by the concentrated solar.... 3. I think making a solar powered Train Steam Engine would be pretty cool to do ;) Keep up the good work Dan :) ~Jesse Mercury
Hey Dan how does the empty tube get destroyed when you leave it in the sun. I can understand if water hits it might shatter. Does the glass deform or something?
Another great vid. One of the things that makes your videos so enjoyable to watch is how frequently you anticipate what viewers may be thinking or reacting to. Great job as usual.
Yes, but they are white colored and the focal point is broad so they only get about 140f. The tube exterior is insulated and cool to the touch on the outside. So the ties work for a test. For long term usage a metal wire etc.
Hey Dan, I know how you could build this in less than 5 minutes :) What you need: 1 Sheet of the reflective metal. 2 - 5 foot sections of 3/8 " bolt rod 2 - 2 1/2 foot secitons of 3/8 bolt rod 1 - 3 foot secton of 3/8 " bolt rod 4 - 4 4 foot sections of bolt rood. Misc 3/8's Nuts and washers.... Instructions: 1. Drill a total of three holes lengthwise along one side of the metal sheeting that are 3/8 inch in diameter. One must be in the center on the edige legnthwise and the other tow at both ends. 2. Repeat step 1 for the opposite lengthwise side. 3. place 5 foot long bolt rods between matching holes lengthwise along both edeges at the ends with a nut and washer on the interior face and exterior face. 4. Tighten said buts to adjust initial curve shape. 5. run the two 2 1/2 foot bolts down through the center holes along either edge in the same fashion with nuts on both sides to adjust vertical tension and shape.... 6. Affix the two 3 foot sections perpendicular to the lengthwise rose in the same fashion to make the shape rigid. 7. Use the 4 foot bolt rods against the "top" lengthwise bolt rod at an angle and into the ground to adjust angle of mirror... Je suis fini!
See your equipment list. simpler suggestion follows. flexible mirror. string. drill 4 holes one per corner drill 2 more holes opposite each other on the proposed curved axis at the midpoint. make your preferred parabolic shape...then thread your string....and tie off the points so they become stable. If done right....you should get two isoceles triangles. by attatching a seperate piece of string to the midpoint of each string and running it to the axis...the whole structure can be held more stable.
2 types of panels lower wattage/power panels usually are thin film amorphous (black colored). However: If the lower wattage panel is a 36 cell configuration, then the cells are smaller. Even a small piece of a broken cell will produce 0.5 volts but proportionally less current. When 36 cells of any size are tabbed together in series they = 36 x 0.5 = 18 volts - 21 volts open no load. Larger cells produce more current but the same voltage.
Hi Jennifer, It does not help. The size of the Fresnel Lens, Parabolic Mirror or Parabolic Trough = surface area and they all "concentrate" sunlight vs "amplifying" sunlight. When one is focused on the other, the only thing that happens is a smaller focal pattern but higher temperatures are not achieved because the second receiving trough, mirror or lens absorbs some light at a sharp concentration factor. This results in whatever gain for a tighter spot being lost by the second element absorption. Here is a video I did with a secondary optical glass lens: th-cam.com/video/zuthle6k94A/w-d-xo.html Thank you for the question and please feel free to ask.
I notice that you bent your sheet along the long axis, creating a short, wide parabola. Could you bend it 90-degrees to the current axis, so you get a long, narrow parabola?
Love it, where did you get the mirror steel? Most plastic companies have mirror plexiglas. You could get up to 800 w per sq meter with insulation and tweeking, but if you orient horizontally and use through tubes instead of capped for your evacuated tubes you can bump surface area to 10-15 kw and use heated liquid to heat house in winter north of 40th parallel. Consult local industrial controller people for pump/temp controls. Also controller or radiator has to be added to avert from sun when fluid temp exceeds danger point, 180F for water, 500F for silicon oil. Pipe couplings above 200F then need to use high temp solder and 1000 to 10000 gallon heat storage tanks are needed. Also, some evac. tubes won't go above 300F, check specs.
Sailgoat I'd like to speak with you if you have a private contact method and are still current on the solar thermal game. Lots of wishy washy info out there in this space, yours is spot on.
Dan! Awesome videos on vacuum tubes and parabolic concentrators... but we will always get stuck on the solar tracking for those parabolic mirrors.. do you have any DIY videos on solar tracking? I ask because the parabolas will only work efficiently during some hours, on those examples you made.. or not? are they effective when they're in a fixed position?
Just brainstorming here, but... say you used a small solar fan (which I have) to force cooler air into a suspended metal tube at the focal point. Would there be enough reflective energy to warm the air noticeably from bottom to top, so that you could circulate the warm air back into something like a small shed or chicken coop? Maybe coil some black hose - like a phone chord - up through the metal tubing to keep it inside a bit longer? Just curious.
a heat exchanger or radiator from a car would work well. radiator would be a big project tho. get the warm air by pulling it through the hot radiator, like in a car. instead of using it to cool the radiator, you are instead using the radiator to heat the air.
I'm not sure if this is correct but I saw some chinese made evac tubes on ebay and the specs said 116 psi. not sure if thats right and if its enough pressure to directly use the steam to run an engine / generator
I’m planning on making a small wall garden on my kitchen porch. The wall faces east, and the plants would be inside the porch facing west. Would something like this allow them to get sufficient sun?
What about using a dowel to snug down the center of your catenary-parabola so it doesn't deform? This is cool. If you wanted to get the maximum heat from it would you not have to track the sun with it, and if you moved it around how much would it deform the mirror as you leave the 90-degree straight up point?
If it is stainless steel, one could use rare earth magnets to hold the sheet in place and even control the shape if needed. This would also allow you to keep a stronge degree of adjustability without blocking the reflective side at all.
Dan. I love you instructional videos. I have been use you platform for many ideas. How ever I am having a hard time finding the material that you show. IE the flexible Mirror. Rolled mirror tape. Can you please send me in the right direction as to where I can get these materials. Thank you Tinyson
An oddball thought. What about using this to make a circular mirror, where the focus point is quite dispersed, then using a small amount of solar panels along the centre. You'd have to be careful that the beam was sufficiently dispersed not to cook the panels, but it might be a way of getting high efficiency from a small area of solar cells by using the mirror to collect light from a wide area.
was wondering... with that trough setup, if instead of an evacuated tube and water... it was just a black steel pipe, or even rain gutter downspout... and then have a 12v fan (powered by solar of course) draw air through the pipe... could this application be used in heating in the winter?
Where do you get that stuff "Mirror" I found it online but its like 300 bucks for stainless steel mirror 60 inch by 24'' 22 gauge I just need something like in the video Thanks
@opaldragon75 I like your thought process but I doubt that it would work in this application. 400 series stainless is magnetic but just observing this on the video I would guess that it is 300 series which is nonmagnetic.
I've got an old 3m in dia satellite dish. Would like to use it to heat up water in a stainless steel 120l cooker that has a 30mm thick base welded to it. I wanted to place the cooker up higher so that the dish can be pointed from low level to the bottom of that plate. My question is: how do i do it so that i can archive a boiling water? Should i place the whole dish in oval mirrors that are secured on silicon or liquid nails to the dish, pointing to the middle point of the dish? I also have a small magnifying glass in metal frame that i can use in the middle instead of the old converter. Will that work? Please any advice or ideas Best regards and greetings from sunny Australia
@GREENPOWERSCIENCE, interesting. I wasn't aware that you could boil water without concentrating sunlight. Do you know the minimum light density to cause a boil?
Question: I want to make a parabolic trough to super heat a 1" black pipe fixed with a solar powered fan to pump a constant flow of warm/ hot air into my house in the winter. I have only seen water heaters using this method, but not moving air. I live in GA and we rarely see snow, and tend to get decent enough sunlight at my house most days. I'm aware that sunlight Ray's drop to nearly 10%, but moving air through an insulated pipe should yield "warm enough" temperatures to help offset my propane furnace consumption. Will this work? And if anyone has tried, what where your results? Thank you
@OSPFlyingwheel Thats why I commented. my new question is what the difference between the 300 & 400? There are many site that sell custom magnets. it is a tempting project for me to think about for next year.
what about doing solar distillation? I found a good price for 10 tubes and thinking about doing this instead of using $6 worth of electricity to generate distilled drinking water.
You need to check your math. Gravity will not create a parabolic trough, but rather a catenary. The depth of the catenary is the hyperbolic cosine. However, a parabola is a simple second degree equation created by squaring the independent variable. Even still a catenary will focus light to an extent, but not like a parabola..
Is that a true parabola or a catenary, or something else? A catenary is a U-shaped curve that an idealized hanging chain or cable assumes when supported only at its ends in a uniform gravitational field. It is similar in appearance to a parabola, but it is not. The word "catenary" comes from the Latin word catena, which means "chain" Here is a bit from some website talking about this: To determine when a catenary will reflect like a parabola, I modeled the problem mathematically on a computer. As expected, I found an aspect ratio where a catenary reflector almost matches a parabolic mirror at concentrating light: 1 high to 4 wide, for a symmetrical reflector. In other words, let the material hang down ¼ the distance between the posts. Following this formula, a couple of teenagers built an effective SCR cooker using hand tools in 20 minutes, under my guidance. Surprisingly, it turns out that a properly proportioned asymmetric catenary reflector (ACR), where one support is higher than the other, will do a good job at concentrating light that’s not exactly perpendicular to the axis of the curve. This means that within certain limits, an ACR can concentrate the light as the sun travels across the sky.
Imagine this along the front of a house facing south. The parabolic lens could be smaller and rotate around the tube to adjust for sun height during season change. The vaccum tubing could be an additional hot water supply for the home and could span the entire length of the home with mirrors the entire way. It could also be stacked in rows on top of one another to heat numerous pipes for larger households.
pls advise 48" standard steel mirror on trough can obtain what temperature for how much volume of water in day time I m in western India it is hot in general advise
+GREENPOWERSCIENCE, hello dan, just a thought. i understand that a vacuum is a good insulator, what i'm going to delve in is the inner workings of the tube..i'm thinking about going solar using this technology. and i have a 7 year background in hvac. my thoughts on this would be to make the inner tube out of a loop of copper tubing (maybe make the tubing using a straight drop out of hard copper and a spiral return around the drop from soft copper) hoping you understand what i'm saying, paint it flat black and using a parabola behind it, but i was thinking about, what to fill the heat exchanger with.. and it hit me. i want to fill the tube with freon. then run the freon in insulated tubing to a heavily "closed cell" foamed insulated reservoir tank above the panel. using convection as a passive pumping system. the only active pump used would be for the cold water feed to the tank. then send it to other sources of use. like radiant heat, running polybutylene tubing under the floors and and spray foam the flooring to seal in the wonderful warmth. if i can make enough heat from it, then i could cook with it. and use a tempering valve for the other household needs. what would be your thoughts on the use of freon as the thermal exchange media. i've even thought of using a underground thermal storage well using zeolite. and the well would be a 500 gal. to 1500 gal lined septic tank, with a coiled up soaker hose attached to the top, then extract the stored heat when needed. using 24 volts on a washing machine valve. and low voltage control signals coming from a Honeywell "three stage" thermostat. ok as i review this post i'll stop >here
Dan, how much water did you boil here? 14 minutes, approximately 1 sq m of sunlight, we can work out how many BTUs you got - very interesting datapoint to measure the efficiency of concentrated sunlight
I think the effective working volume of those tubes is 1L so using that I get a figure 1,354BTU/h or ~400W ~316BTU over the course of the 14 minute boiling time, all assuming a starting temp of 70F for the water. I've heard these tubes quoted as operating at ~80W without a reflector so that's pretty impressive.
@catfish4975 You'd better be aware that system efficiency is going to blow away a lot of the gathered energy, and you'll be lucky to collect more than 150W/M2 Thus the cost of your tracking mechanisms, pipes and seals will mount up It's is better to first ensure your house is properly insulated, with ventilation heat recovery, before investing in a large reflector assembly with a relatively small return. Where do you live?
36 solar cells provide 18 volt voltage. Why some of them has very high watts, like 150 watts, while others has low watts, like 5 watts? what's the difference between these cells?
@dallasgoldbug Ive noticed i can thumb someone up or down and refresh the page several hours later and they still have no thumbs or the thumb number hasn't changed, so i wonder if "radical" people are being censored other then comments, which would be too obvious.
Good bro I am required 25 kw Stirling engine generator for dish parabolic. I am searching for supplyer but I can't get . Please tell me how can I get Stirling solid generator. I am from Pakistan
if this mirror were say, at the bottom of a kiddie pool, would it heat the water from the sun passing through the water then reflecting back from the mirror?
To heat a pool, just place black objects at the bottom. Mirrors in the water reflect sunlight away. WHite pool bottoms or mirrored pool bottoms are ways of keeping water cooler vs warming. Water is clear so it does not absorb light well regardless of the bounce passes. Just make sure objects are removed before anyone swims. SIMILAR PROCESS; Fresnel Lens to heat a swimming pool with solar energy
Thanks Dan, great video. But somethings not matching up for me. Maybe I'm not calculating this correctly. The sun puts out 1000 watts/m2 on an average clear day. Looks like your parabolic trough is at least a square meter. Using your numbers above I estimate your putting 294 Joules of heat into the solar vacuum tube over 14 minutes, equaling 0.35 watts of power. But I've read parabolic troughs can be equivalent (around 15%) to solar cells. Doesn't seem like your system is coming close to this.
Very cool stuff indeed! I was wondering, can the concentrated sunlight be magnefied again somehow to multiply its ''heat'' so that it would cook faster? In other words, find the focal point and put another (perhaps thicker) lens to ''re-focus'' even more the power of the sun? It would be nice to see this tried. Keep up the good work, love all your videos!
Have you seen his electric bill, water bill, or the interior of his house? Do you have any data that suggests that he hasn't found a practical application for what he shows on TH-cam?
can you focus a full moon beam with this and see how much power you can get off a photo voltaic cell? .... How much can you focus on photo voltaic cell without burning it out?
Dan bro you made what i wanted and not the equations of a parabolic mirror. Nice work. Straight up. No left or right.
@judoyodan it is a dark inner surface with a vacuum around it. Vacuums do not transfer heat well, they are a vary good insulator. Sunlight penetrates the clear outer glass and heats the black coating delivering heat to the water. Heat can only escape through the top. This builds temperature fast. This is a typical glass thermos but clear on the outside vs silver.
@GREENPOWERSCIENCE this is the same principle as the solar farms that use a field of adjustable mirrors to superheat a collector to boil water for electricity production, just on a much much smaller and more practical scale. I like!
Dan ... Just thought of a couple of things ...
1. The Center hold down spar? You make it out of wood sooooo if you used a tensioned wire there.. say 12 Gauge Copper Wire? (no insulator) tensioned by by a bolt, two nuts, and two washers on the underside on the spar on the reverse side.. you could have less possible light lost and likely it would be cheaper as all the items I just mentioned can be sourced from objects that get thrown out everyday.
2. If you wanted to use this as a boiler for a steam turbine I would run a water inlet and outlet hole into the umm boiler unit... have a valve that allows the steam out for the outlet... through your turbine and then to your water tank to pressurize it to sort of force feed the boiler fresh water... also I would insulate the top length of the boiler unit as ummm while it is a vacuum thermos type deal.. it well honestly you are likely losing more heat out of the side not being hit by the concentrated solar....
3. I think making a solar powered Train Steam Engine would be pretty cool to do ;)
Keep up the good work Dan :)
~Jesse Mercury
This guy is AMAZING!! Bet he won a couple of science fair projects in school
Hey Dan how does the empty tube get destroyed when you leave it in the sun. I can understand if water hits it might shatter. Does the glass deform or something?
Another great vid. One of the things that makes your videos so enjoyable to watch is how frequently you anticipate what viewers may be thinking or reacting to.
Great job as usual.
Dan I love all of your videos, please don't stop.
Yes, but they are white colored and the focal point is broad so they only get about 140f. The tube exterior is insulated and cool to the touch on the outside. So the ties work for a test. For long term usage a metal wire etc.
Hey Dan, I know how you could build this in less than 5 minutes :)
What you need:
1 Sheet of the reflective metal.
2 - 5 foot sections of 3/8 " bolt rod
2 - 2 1/2 foot secitons of 3/8 bolt rod
1 - 3 foot secton of 3/8 " bolt rod
4 - 4 4 foot sections of bolt rood.
Misc 3/8's Nuts and washers....
Instructions:
1. Drill a total of three holes lengthwise along one side of the metal sheeting that are 3/8 inch in diameter. One must be in the center on the edige legnthwise and the other tow at both ends.
2. Repeat step 1 for the opposite lengthwise side.
3. place 5 foot long bolt rods between matching holes lengthwise along both edeges at the ends with a nut and washer on the interior face and exterior face.
4. Tighten said buts to adjust initial curve shape.
5. run the two 2 1/2 foot bolts down through the center holes along either edge in the same fashion with nuts on both sides to adjust vertical tension and shape....
6. Affix the two 3 foot sections perpendicular to the lengthwise rose in the same fashion to make the shape rigid.
7. Use the 4 foot bolt rods against the "top" lengthwise bolt rod at an angle and into the ground to adjust angle of mirror...
Je suis fini!
See your equipment list.
simpler suggestion follows.
flexible mirror.
string.
drill 4 holes one per corner
drill 2 more holes opposite each other on the proposed curved axis at the midpoint.
make your preferred parabolic shape...then thread your string....and tie off the points so they become stable.
If done right....you should get two isoceles triangles.
by attatching a seperate piece of string to the midpoint of each string and running it to the axis...the whole structure can be held more stable.
2 types of panels
lower wattage/power panels usually are thin film amorphous (black colored).
However:
If the lower wattage panel is a 36 cell configuration, then the cells are smaller. Even a small piece of a broken cell will produce 0.5 volts but proportionally less current. When 36 cells of any size are tabbed together in series they = 36 x 0.5 = 18 volts - 21 volts open no load. Larger cells produce more current but the same voltage.
Great sounds too!
Dan, is there any advantage to combining a fresnel lens with a parabolic trough? Will it achieve higher temperatures?
Hi Jennifer,
It does not help. The size of the Fresnel Lens, Parabolic Mirror or Parabolic Trough = surface area and they all "concentrate" sunlight vs "amplifying" sunlight. When one is focused on the other, the only thing that happens is a smaller focal pattern but higher temperatures are not achieved because the second receiving trough, mirror or lens absorbs some light at a sharp concentration factor. This results in whatever gain for a tighter spot being lost by the second element absorption. Here is a video I did with a secondary optical glass lens:
th-cam.com/video/zuthle6k94A/w-d-xo.html
Thank you for the question and please feel free to ask.
I notice that you bent your sheet along the long axis, creating a short, wide parabola. Could you bend it 90-degrees to the current axis, so you get a long, narrow parabola?
Okay; how about giving them more sunlight to concentrate? Flat mirrors on a heliostat putting more illumination on the back side of the fresnel?
What was the entire cost? Any chance of getting metric values in the future?
Love it, where did you get the mirror steel? Most plastic companies have mirror plexiglas. You could get up to 800 w per sq meter with insulation and tweeking, but if you orient horizontally and use through tubes instead of capped for your evacuated tubes you can bump surface area to 10-15 kw and use heated liquid to heat house in winter north of 40th parallel. Consult local industrial controller people for pump/temp controls. Also controller or radiator has to be added to avert from sun when fluid temp exceeds danger point, 180F for water, 500F for silicon oil. Pipe couplings above 200F then need to use high temp solder and 1000 to 10000 gallon heat storage tanks are needed. Also, some evac. tubes won't go above 300F, check specs.
Sailgoat I'd like to speak with you if you have a private contact method and are still current on the solar thermal game. Lots of wishy washy info out there in this space, yours is spot on.
I have interest in high efficiency > 95% reflecting
material / metal
How much does the metal cost and what is it's weight?
I like also the sounds of that mirror. Have to sample that and use in some experimental techno... :P
can I use a holes that is black inside a used old light tube, Charles
Dan! Awesome videos on vacuum tubes and parabolic concentrators... but we will always get stuck on the solar tracking for those parabolic mirrors.. do you have any DIY videos on solar tracking? I ask because the parabolas will only work efficiently during some hours, on those examples you made.. or not? are they effective when they're in a fixed position?
Just brainstorming here, but... say you used a small solar fan (which I have) to force cooler air into a suspended metal tube at the focal point. Would there be enough reflective energy to warm the air noticeably from bottom to top, so that you could circulate the warm air back into something like a small shed or chicken coop? Maybe coil some black hose - like a phone chord - up through the metal tubing to keep it inside a bit longer? Just curious.
a heat exchanger or radiator from a car would work well. radiator would be a big project tho.
get the warm air by pulling it through the hot radiator, like in a car. instead of using it to cool the radiator, you are instead using the radiator to heat the air.
How much did that SS Mirror cost - $200.00, $300.00?
I'm not sure if this is correct but I saw some chinese made evac tubes on ebay and the specs said 116 psi. not sure if thats right and if its enough pressure to directly use the steam to run an engine / generator
I’m planning on making a small wall garden on my kitchen porch. The wall faces east, and the plants would be inside the porch facing west. Would something like this allow them to get sufficient sun?
What about using a dowel to snug down the center of your catenary-parabola so it doesn't deform? This is cool.
If you wanted to get the maximum heat from it would you not have to track the sun with it, and if you moved it around how much would it deform the mirror as you leave the 90-degree straight up point?
If it is stainless steel, one could use rare earth magnets to hold the sheet in place and even control the shape if needed. This would also allow you to keep a stronge degree of adjustability without blocking the reflective side at all.
Dan. I love you instructional videos. I have been use you platform for many ideas. How ever I am having a hard time finding the material that you show. IE the flexible Mirror. Rolled mirror tape. Can you please send me in the right direction as to where I can get these materials. Thank you Tinyson
Que es el tubo que pones encima y de que material esta hecho, saludo y buen trabajo.
How could you make a box oven using the trough mirror?
Thanks for this quick reply. Large and single crystal cells produce the most power.
An oddball thought. What about using this to make a circular mirror, where the focus point is quite dispersed, then using a small amount of solar panels along the centre. You'd have to be careful that the beam was sufficiently dispersed not to cook the panels, but it might be a way of getting high efficiency from a small area of solar cells by using the mirror to collect light from a wide area.
...Yes but try only with the vacuum tube ( Without mirror and rack ), the oil inside the tube is heated up to 180 ° C
I did it .
Have a nice day.
was wondering... with that trough setup, if instead of an evacuated tube and water... it was just a black steel pipe, or even rain gutter downspout... and then have a 12v fan (powered by solar of course) draw air through the pipe... could this application be used in heating in the winter?
Yes. It would work.
But whether or not it would be financially feasible - is the real question.
Where do you get that stuff "Mirror" I found it online but its like 300 bucks for stainless steel mirror 60 inch by 24'' 22 gauge
I just need something like in the video
Thanks
@opaldragon75 I like your thought process but I doubt that it would work in this application. 400 series stainless is magnetic but just observing this on the video I would guess that it is 300 series which is nonmagnetic.
304
I've got an old 3m in dia satellite dish. Would like to use it to heat up water in a stainless steel 120l cooker that has a 30mm thick base welded to it. I wanted to place the cooker up higher so that the dish can be pointed from low level to the bottom of that plate.
My question is: how do i do it so that i can archive a boiling water? Should i place the whole dish in oval mirrors that are secured on silicon or liquid nails to the dish, pointing to the middle point of the dish? I also have a small magnifying glass in metal frame that i can use in the middle instead of the old converter.
Will that work?
Please any advice or ideas
Best regards and greetings from sunny Australia
How deep is the bottom to achieve the focal point to where it is in the video? Thanks.
What is the name of the is reflective metal and Wwere do you get it?
@GREENPOWERSCIENCE, interesting. I wasn't aware that you could boil water without concentrating sunlight. Do you know the minimum light density to cause a boil?
Question: I want to make a parabolic trough to super heat a 1" black pipe fixed with a solar powered fan to pump a constant flow of warm/ hot air into my house in the winter. I have only seen water heaters using this method, but not moving air. I live in GA and we rarely see snow, and tend to get decent enough sunlight at my house most days. I'm aware that sunlight Ray's drop to nearly 10%, but moving air through an insulated pipe should yield "warm enough" temperatures to help offset my propane furnace consumption. Will this work? And if anyone has tried, what where your results? Thank you
btw with what I suggested.... by adjusting the four sets os bolts? you can get a perfect parabolic shape.....
Is this non magnetic 304 S.S or 316L S.S. ? and where can you buy this from?
Free energy.. cool
@OSPFlyingwheel Thats why I commented. my new question is what the difference between the 300 & 400? There are many site that sell custom magnets.
it is a tempting project for me to think about for next year.
Simple and effective! Thanks for sharing.
hi, love your video's. your 30mill parabola inspiriring. why not spray crome on the visquin and dissolve plastic
?
Shiny side of Aluminium foil usable?
I know this is old, but what stopped the plastic zip ties from melting?
Cool. Practical application?
does the mirror come in many dimensions?
what about doing solar distillation? I found a good price for 10 tubes and thinking about doing this instead of using $6 worth of electricity to generate distilled drinking water.
You need to check your math. Gravity will not create a parabolic trough, but rather a catenary. The depth of the catenary is the hyperbolic cosine. However, a parabola is a simple second degree equation created by squaring the independent variable. Even still a catenary will focus light to an extent, but not like a parabola..
Xysix hi what shape or how can i set it up to create airheat with a large black pot for baking?
Xysix I don’t know what that means
Is that a true parabola or a catenary, or something else?
A catenary is a U-shaped curve that an idealized hanging chain or cable assumes when supported only at its ends in a uniform gravitational field. It is similar in appearance to a parabola, but it is not. The word "catenary" comes from the Latin word catena, which means "chain"
Here is a bit from some website talking about this:
To determine when a catenary will reflect like a parabola, I modeled the problem mathematically on a computer. As expected, I found an aspect ratio where a catenary reflector almost matches a parabolic mirror at concentrating light: 1 high to 4 wide, for a symmetrical reflector.
In other words, let the material hang down ¼ the distance between the posts. Following this formula, a couple of teenagers built an effective SCR cooker using hand tools in 20 minutes, under my guidance.
Surprisingly, it turns out that a properly proportioned asymmetric catenary reflector (ACR), where one support is higher than the other, will do a good job at concentrating light that’s not exactly perpendicular to the axis of the curve. This means that within certain limits, an ACR can concentrate the light as the sun travels across the sky.
Imagine this along the front of a house facing south. The parabolic lens could be smaller and rotate around the tube to adjust for sun height during season change. The vaccum tubing could be an additional hot water supply for the home and could span the entire length of the home with mirrors the entire way. It could also be stacked in rows on top of one another to heat numerous pipes for larger households.
@GREENPOWERSCIENCE Oh great thanks man. appreciate it. i forgot to mention, great work on the videos. I really do enjoy watching them.
I need highly reflective mirror for my project. Can you tell me what mirror is that. Is it Stainless Steel 430? Thanks!
SS 304
where did you get the metal from? is it just a simple mirror?
pls advise 48" standard steel mirror on trough can obtain what temperature for how much volume of water in day time
I m in western India it is hot in general
advise
How does that "tube" on it's own boil water?
How much does the SS sheetmetal cost per piece like this one?
hi sorry what are the properties of this
mirror
+GREENPOWERSCIENCE, hello dan,
just a thought. i understand that a vacuum is a good insulator, what i'm going to delve in is the inner workings of the tube..i'm thinking about going solar using this technology. and i have a 7 year background in hvac.
my thoughts on this would be to make the inner tube out of a loop of copper tubing (maybe make the tubing using a straight drop out of hard copper and a spiral return around the drop from soft copper) hoping you understand what i'm saying, paint it flat black and using a parabola behind it, but i was thinking about, what to fill the heat exchanger with.. and it hit me. i want to fill the tube with freon. then run the freon in insulated tubing to a heavily "closed cell" foamed insulated reservoir tank above the panel. using convection as a passive pumping system. the only active pump used would be for the cold water feed to the tank. then send it to other sources of use. like radiant heat, running polybutylene tubing under the floors and and spray foam the flooring to seal in the wonderful warmth. if i can make enough heat from it, then i could cook with it. and use a tempering valve for the other household needs. what would be your thoughts on the use of freon as the thermal exchange media. i've even thought of using a underground thermal storage well using zeolite. and the well would be a 500 gal. to 1500 gal lined septic tank, with a coiled up soaker hose attached to the top, then extract the stored heat when needed. using 24 volts on a washing machine valve. and low voltage control signals coming from a Honeywell "three stage" thermostat. ok as i review this post i'll stop >here
Interesting idea. Using Freon is out of my league, but would seem risky.
how do you make electric from steam ?
Great! This looks like it would make a great school science project for my granddaughter May I ask where you got the Stainless Steel sheet?
May i know what is the thickness of the stainless steel?
@cdltpx You might be able to get 50-100 watts out of it...You would need 25 of them to power your house.
It works for great for cooking though!
what about small wood clamps? You can hold the mirror with out damage and get the most out of the sun.
Imagine a vacation package where you stay and play inventor for a week with Dan Rojas. That would be a blast!
shouldn't the curve of this sheet be Catenary, instead of a parabola?
HI, where can i get that mirror and how much for it. Thanks
What precautions you take to prevent starting a house fire?
What precautions do you take to prevent cutting your fingers off when making food?
SImple and efficient! COngratulations!
Dan, how much water did you boil here? 14 minutes, approximately 1 sq m of sunlight, we can work out how many BTUs you got - very interesting datapoint to measure the efficiency of concentrated sunlight
Anders Haagen
muito bom essa experiência
I think the effective working volume of those tubes is 1L so using that I get a figure 1,354BTU/h or ~400W ~316BTU over the course of the 14 minute boiling time, all assuming a starting temp of 70F for the water. I've heard these tubes quoted as operating at ~80W without a reflector so that's pretty impressive.
Can this be used to run a steam engine driven generator?
You'd be better off with a sterling generator!
Throw a water tank in front of that thing and lets get another Denise taking a bath video! Just kidding (or am I?). Love the videos...Nice work Dan!
are those plastic zip ties? wouldn't they melt?
what are the dimensions of that cubic wooden box ?
How do you calculate the focal point of a parabolic mirror?
a parabola has two foci... they are fundamental to the nature of a parabola, a mathematical point similar to a 'circle that has two centers'
@catfish4975 You'd better be aware that system efficiency is going to blow away a lot of the gathered energy, and you'll be lucky to collect more than 150W/M2
Thus the cost of your tracking mechanisms, pipes and seals will mount up
It's is better to first ensure your house is properly insulated, with ventilation heat recovery, before investing in a large reflector assembly with a relatively small return. Where do you live?
I think you should paint that tube in black, nice vid. great ideas !
nice work dan
great mirror & video , some nice wobbly sound effects too. : )
Great stuff as usual. Thanks,
can you deliver this product in india?
@BeeRich33 Solar energy is free an abundant. But it has one fatal flaw, it only works during the day.
I made a smaller collector out of aluminum foil and a cardboard box. at less than 10 deg farenheit out, it still boiled in 30 minutes...
crashdown45 ï
crashdown45 are you serious? I'd like to see your set up. Seriously. Same method ? Just draping aluminum what did you do for a water holder?
@MTHKITEBOARDS There is a link in the info section :)
36 solar cells provide 18 volt voltage. Why some of them has very high watts, like 150 watts, while others has low watts, like 5 watts? what's the difference between these cells?
@dallasgoldbug Ive noticed i can thumb someone up or down and refresh the page several hours later and they still have no thumbs or the thumb number hasn't changed, so i wonder if "radical" people are being censored other then comments, which would be too obvious.
""radical""
Rioters probably get double like power for all I know tbh
Good bro
I am required 25 kw Stirling engine generator for dish parabolic.
I am searching for supplyer but I can't get . Please tell me how can I get Stirling solid generator.
I am from Pakistan
make something like this but longer and pump water trough it for shower
if this mirror were say, at the bottom of a kiddie pool, would it heat the water from the sun passing through the water then reflecting back from the mirror?
To heat a pool, just place black objects at the bottom. Mirrors in the water reflect sunlight away. WHite pool bottoms or mirrored pool bottoms are ways of keeping water cooler vs warming. Water is clear so it does not absorb light well regardless of the bounce passes. Just make sure objects are removed before anyone swims.
SIMILAR PROCESS;
Fresnel Lens to heat a swimming pool with solar energy
GREENPOWERSCIENCE
GREENPOWERSCIENCE
aaahh yes! and a catenary is a mix of sinh and cosh....so it isn't parabolic but it works so probably it's very similar
So if You used this set up and a water lens above it would it become more effective ?
ok.. where was Denise in this one??
Thanks Dan, great video. But somethings not matching up for me. Maybe I'm not calculating this correctly. The sun puts out 1000 watts/m2 on an average clear day. Looks like your parabolic trough is at least a square meter. Using your numbers above I estimate your putting 294 Joules of heat into the solar vacuum tube over 14 minutes, equaling 0.35 watts of power. But I've read parabolic troughs can be equivalent (around 15%) to solar cells. Doesn't seem like your system is coming close to this.
Very cool stuff indeed! I was wondering, can the concentrated sunlight be magnefied again somehow to multiply its ''heat'' so that it would cook faster? In other words, find the focal point and put another (perhaps thicker) lens to ''re-focus'' even more the power of the sun? It would be nice to see this tried. Keep up the good work, love all your videos!
By my figures, you were getting 225W out of that mirror. Probably a little more due to losses through the top. About right?
Excellent !! Thanx
Have you seen his electric bill, water bill, or the interior of his house? Do you have any data that suggests that he hasn't found a practical application for what he shows on TH-cam?
can you focus a full moon beam with this and see how much power you can get off a photo voltaic cell? .... How much can you focus on photo voltaic cell without burning it out?
moonlight is polarised light
if I may
wat
The pipe isn't worth it bro