The heated aluminium disc should be dark, black (but not catch fire) to use enough of the light that is focused on it (as it's well known, the darker the object, the better it heats up). And, I'm sure you've considered this, but just in case: of course each segment must be the shape of the corresponding part of a parabola, not of the parabola's centre.
If the focus point will be few centimetres above aluminium disk, trap for light could be made: second disk with small hole that will be few centimetres above main disk and aluminium wall between two disks. that way almost all light will get through the hole in the first disk and then rereflect many times inside our trap, heating everything up. This also will stop wind from cooling main disk. And of course all walls inside trap should be black - main disk heat resistant paint and other walls of the trap could be painted with black 3.0 to really boost performance.
Not necessarily, if all parabolic mirrors (and their respective focal points) are equidistant to the secondary mirror/heater plate. It's way cheaper and faster to have one mold for all mirrors.
3d Printing 6 different forms (as it's rotationally symmetrical, you should be able to reuse them) probbably isn't too much overhead, but I'm not certain it's worth it. In case of remoulding, a vacuum attatched to the negative mold might pull the plates into shape without damaging the mirrors finish by compressing them from the top. A more expensive option might be to get copper-clad plexiglass for the panels, form them and then electroplate them silver. The upside is you should be able to get a very eaven coat by placing the opposite electrode at the focal point of the mirror, so it's fairly equidistant from all points (minus the spherical/parabolic deviation) That would hopefully remove some of the waviness you have in your formed sections from the adhesive releasing and/or the film buckling.
Also needless to say, make sure if you paint the plate black, you use temeperature-resistant paint like the stuff the make to paint mufflers or barbecues. Probably need some sort of primer with it as well, although the more different layers you have the worse the thermal conductivity could possibly be.
Building all of this just to be hit with the reality that you live in the Netherlands is very relatable. It's like when me and me dad installed solar panel lights on our house and forgot we get an absurd amount of clouds, so we originally thought we bought defective lights XD
Send me a version for testing in SEA. I already have a neighbor with a similar set up who sells solar roasted chicken on the highway. I will send back a cut of the profits for further R&D.
Do you remember if they were the blue crystalline looking ones or the black ones with stripes? The blue ones have like 4 times the Amp output in relation to surface area but only in direct sunlight. The black ones will output under 4 inches of snow and clouds.
Since you're trying to catch the light on the big plate, the parabolic shape on your primary mirrors is unnecessary. Each petal or mirror segment can be flat and the secondary mirror can be flat; the parabolic effect will come from how each segment is focused on the secondary. Rather than throw a tiny hot spot onto the receiver, let it be bigger and heat the whole thing more-or-less evenly. Lower deltas are less lossy. Also: you really want a dark receiver. Shiny silver will reflect a lot of the incident energy, shiny black will absorb it without re-radiating it so readily. Your ideal surface should be black chrome.
If he wants to achieve a real focus, each mirror should be a section of a paraboloid. Mirrors at the same radius can have the same shape, but the mirrors should be different shapes at different radius values.
I did something like this with a 1.2m satellite dish and aluminium foil, and then a mylar sheet over the dish and partially evacuated the volume behind - it was scary efficient! I used candle soot to coat the bottom of a pan to absorb the energy. At night, I could point it to a clear sky and use it to freeze things!
JWST needs parabolic mirrors to create an image, you do not have the same requirement: you just need all the light from a mirror to reflect on the collector. A plane mirror illuminated by the sun creates a reflection of the same size at most, so the only requirement is to have a collector of the same size of the mirror.
This is a good point, I think a solid compromise that would be especially effective here, is set a reasonable focal goal for the curvatures, small enough to splash the majority of the target for good transfer.
Partially true, but one thing to consider is that the efficiency of a solar heat collector is proportional to the temperature difference you can achieve, and you can get a larger temperature difference for the same size collector by concentrating the light using parabolic mirrors.
Yes, focusing to a point is unnecessary unless you want to melt things - key is to collect energy as heat more efficiently, not concentrate it more than is necessary. The same energy can make a high temperature over a small area, or lower temperature over a larger area, and the latter may be more efficient by maximising heat transfer time to heat the fluid medium by the desired amount. There are a lot of things to consider. Coating the collector with soot from a candle will also increase absorption.
@ No, flat mirrors only fine if the collector is where all the reflections impinge on it on the end of the boom. There is no shape that can then reflect them all to the collector in the centre of the dish as they would all miss except one. In this case they would need to be partially focused to land on a parabolic convex reflector to then land on the collector in the dish, with a suitable radius to provide a temperature enough to heat the water to the desired temperature.
Color isn't really a good indicator for reflectance of infrared light. Actual gold like the stuff used on the telescope would reflect much more light, because the spray paint uses stuff that looks like gold, but isn't, it probably reflects much less light.
Lasers (IR CO2) use gold mirrors, they work well enough up to about 50W. The coating is rather fragile. They're reasonably cheap but small, only 20mm. Telescope dudes will sputter silver onto glass (say 300mm) easily enough, could probably point you towards someone who could do gold. These would have the coating on the front.
As someone who builds solar cookers I've never seen anyone at that level of engineering (except industrial projects). Very impressive and I also like the design👍Looking forward to part 2
One glaring thing that may be a problem... the heat collector is currently reflective. Spray it matt black with heat resistant (stove paint) paint as it will absorb heat much better than the shiny surface.
@@ConceptCraftedCreationsThe fact you're using aluminum gives you an option for making it black: There was research done stating that a simple candle's soot actually forms carbon nanotubes onto the aluminium surface. Simply put, just soot the aluminium disc with a candle and gently have something transparent to protect it from the elements. Used this for my solar space heater, works well, however haven't tested if simply painting it black has any difference. But theoretically the nanotubes would be perfect light capturers.
xD (I'm not American) My salary is less than $100 a month, however I recently allowed myself a set of 200 springs for $5 for the sake of 4 springs :) But the springs can really be replaced with alternatives, and the bearing is specific and very important, I guess it's just the man was choosing what to spend money on and what is not worth it
@@broniusale5987 Yeah, I don't understand what that was about either. Just looked at temu, searched for springs: springs galore for 10 to 20 ct a piece.
Instead of allowing the water to flow through the collection plate under acrylic, I would of put copper tubing and soldered it into place to make better contact. Better contact allows for more efficient transfer of thermal energy. Also, the water will get very hot and start to build up pressure which can cause the acrylic to start to flex under the pressure, plus the heat making it softer. On my single solar thermal collector I had on a 2ftx4ft panel, the water would start boiling before exiting the system, which led to a lot of a air locking keeping the water from flowing smoothly. The system *had* to run under pressure to keep the water from boiling so easily.
Yeah, that acrylic backplate is just begging for leaks. The mirror tests already show it can significantly flex at 100C, and there's going to be a lot of water/steam pressure in there.
Very good project. 1. Place the heat receiver on the rods, and not reflect the light twice, which only leads to double losses due to light reflection. 2. Paint it black or smoke it with soot. 3. It is possible to apply a reflective coating after forming the bend of the mirror, in order to avoid cracks when heated. 4. Add a protective layer on top of the reflective one, since it is difficult to maintain the integrity of the coating in the sun, wind and rain. Plus, the second layer can be polished with a car polishing machine. 5. Replace tracking by lighting level with a simple table of the sun's location by time of day (but then you need to add potentiometers or decoders to the rotary axes). 6. If you want to leave the installation outside for a long time, you need to add a protective function to avoid strong winds, add a wind sensor or simply take information from the local weather forecast (mirrors are just a big sail)
Gold paint ≠ gold reflectivity Silver paint ≠ silver reflectivity At least outside of the visible spectrum. Paint just looks the part -it's optical properties are totally different to precious metals and also different to whatever coating is on your plastic mirrors.
Yeah, I thought there was no way you could finish the whole project in only a 13 and a half minute video. Well, you are almost done. Can't wait for part two!
Issue, their is a maximum amount of energy a solar panel can convert, in fact as the solar panel heats up the conversion rate of the crystals drop. Layered solar panels with water cooling is now a better method to increasing the energy efficiency. So focusing on less solar panel material probably won't help much unless your in winter.
The only thing I would have done differently is just make one huge parabolic instead of segmented ones. I also would like to see how it's going to be used because I'm having trouble understanding how other than just heating water what use is it? granted heating water is pretty useful too.
Easier to replace a single failed mirror from an array, rather than having to replace the whole thing. Also easier to make small mirrors than big ones Also easier to correct for flaws etc with small mirrors than one big one. There are some advantages to a solid mirror. There are some advantages to a mirror array. 🤷♂️
If you point it at a solar panel you can get a lot of power out of it. Most aren't rated for that level of power though so for consumers a heat based generator might be more plausible
Did you apply the paint at the front of the acrylic panes? It wasn't clear to me, it would be best to apply it at the back like with any mirror. Then the aluminium core plate must be painted matte black of course, you do not want that to act as a mirror too. I expect some issues with boiling, tubes may burst or come off. You may need to control the water flow based on the plate's temperature, making sure it won't exceed 90 degrees Celcius or so. And using astronomical data tables for your date and location seems more effective than trying to figure out where the sun is in real time. This is how all trackers for solar panels work. Overall I am impressed once again.
Yeah, he's going to need a lot of water pumping through that block to keep the sink below boiling temperature, which means needing a constant use for the hot water. Recycling got water will also make it boil. Honeslty, being able to form the plexiglass mirrors at 100C means getting any where close to boiling will cause the seals around the plexiglass backplate to pop. The tempreature and constant water/steam pressure will warp it.
Paint the heat collector black, as silver reflects...no need for individual curved mirrors, as the current setup uses low reflectivity film. Rather user real flat mirrors and get all reflections from the flat mirrors to overlap on the heat collector. More smaller real mirrors may be the way to go.
I think you should create a solar tracker that only requires grid coordinates and a calendar to operate. With those two pieces of information, one should be able to create a platform for solar collectors that is 100% accurate without worrying about it being exposed to the sun.
Using windows tint should allow you to apply it to the curved acrylic AFTER shaping. There is a technique using heat guns that tint shops use to shape the film to curved surfaces. I believe this would allow for a cleaner/smoother surface finish, thereby a more efficient system.
Amazing project, choosing foil on Plexiglas with foil as reflectors....well its cost effective. The bigger problem i see is with using Plexiglas as the back cover for the heat collector. Years ago i tryed to build watercooling blocks from Plexiglas and found out it gets very soft around 60C already, making the seals leak because the skews loose pressure cuz they sink into the plexi.
I don't really understand the spherical/parabola difference in your application: why are you so concerned to focus the light into one point (parabola) instead of leaving it a bit spread out (spherical) if you use a gigantic solar collector (aluminium plate)? By the size of the collector the hexagonal patterns could even remain flat. Another thought: you should have just bought a satellite dish second hand and coat that one. Easy, no?
Great Idea! For the Parabolic Curve. . . You could just Keep the Mirrors Flat Since they already Follow a parabolic curve. Otherwise Each Mirror would have to Have the Individual Corresponding Curve for that Segment of the Overall Parabola of the Dish. Without that Exact Arrangement you will loose Light Density, I personally believe Flat Mirrors Arranged along the Parabolic Curve would Give an Overall Higher Density of Reflected Light though not 100 percent.
That's what I was thinking. I'm sure there are quite a few scientific journals on what's best. there's no need to reinvent the wheel with how much effort is being put into it.
try to cover the heat plate in something extremely dark. Maybe soot for a simple solution, or vantablack (or similar) if they can withstand the heat. That should absorb nearly all the light energy
Very good quality of video overall, no junk or filler. As for tilting mechanism, consider redesigning it. Main problem with current iteration is that it is relatively weak. It may hold light frame with reflectors, but then it'll need to be strong enough to withstand the winds. And winds will potentially double or tripple the loads.
@@ConceptCraftedCreations since it's pretty much pure carbon, it shouldn't burn, but should increase the amount of light energy being absorbed into the aluminum. You could also just hold the sun facing side of the aluminum over a campfire until it collects a good coating of soot.
Really interesting project. My thoughts. Gold paint and gold are obviously different but that’s not important as cost is a factor. You could try using aluminium foil or even “speed tape” (aluminium tape). I don’t think using parabolic mirrors is important if the overall shape is parabolic. You’re just trying to focus the light onto the central mirror and then onto the heat collector. The central mirror may need to be parabolic to focus the energy roughly onto the collector. Why not just stick small mirrors onto a TV dish and try that. Much cheaper especially if you get a scrap one. The dish and mounts are also designed to work in high winds but the weight will mean larger motors and you may need to use a counterbalance to help lessen the load on any motors.
I'm guessing the JWST used a gold coating because it is good at reflecting IR, because imagining in the IR spectrum is what the JWST's main mission is.
I would put the collector at the 1st focus and make it a sphere with a hole in the side to let the light in and stop any reflections from leaving. Imagine machining channels into a hollow sphere with a hole in the side, then coat the inside with candle soot. This way, you won't have to worry about machining a secondary mirror. The parabolic segments reflect just once through the hole in the sphere and everything is captured. I made a solar tracker using an Arduino, GPS module and two servos, (later two steppers) and some code to translate time of day and lat/long location into elevation and azimuth in degrees. Works even when overcast. Add an anemometer then set to elevation to 90° if wind exceeds a limit. Use a linear actuator for elevation - this can take a lot of load. Raise the dish and add a counterweight to reduce static torque. Servos are a pain - they want to slew suddenly to another position at power-on, and that can break things if they don't have a clutch mechanism!
So, you've made a solar concentrator that was invented over 2 millenia ago. There are even modern versions that use molten salts instead of aluminum. I think you should have done more investigation on what has already been done. There are even studies about the best materials to use as receivers. This is inventing in a bubble.
Sometimes if you invent 'in a bubble', you may come up with something new and better than what was done previously, that said examining what has gone before can be helpful and shortcut the design process. Pointless to reinvent the wheel but you could invent something that does the same job but better? Besides he did look at the JWST design for inspiration.
This is a cassegrain antenna design. The formulas are all over the antenna design websites. It is very critical though. and actually you usually want to focus in a single point but for this you should try for a focal point past the plate just where the cone of light would evenly cover the plate.
Anything I would have done? Not use gold and silver paint for one. When it comes to energy, paint is not the same as the actual materials; it's a case of pigment versus metallic elements. Sure, I get that neither one is cheap, but you can only go so far with just substitutes.
@@ConceptCraftedCreations Seemed accurate enough to me, so kudos on that. Seriously though, real silver mirrors will beat just about any substitute in this kind of situation.
@@ConceptCraftedCreations Gold paint, isnt the same color, nor reflectivity, of high purity Gold. For that test, you should use Gold-Leaf. Gold Leaf, is real gold.. just incredibly thin... making it semi-affordable, for coating things like Picture Frames.
You should get a light gray projection sheet or paper to put down on your table when you're using your projector like this, it'll increase contrast and color, as well as reducing reflectivity from the surface as it stands.
Black automotive paint on the heat collector would likely help a lot. Protects the part from weather and increase heat absorption. A rough finish would increase the surface area as well by the tiniest bit to collect as much as possible.
Tip. Have a look at a polar aligned equatorial wedge. You will find tracking easier as all the tracking for the day can be done with one motor running at 1/24 revolution per hour.(the earth is rotating not the sun moving) Why is the disk in the middle silver it will reflect heat & light, it should be the darkest matt black you could find.
id reccomend applying the reflective film after shaping if possible, a heat gun may help with this like applying a wrap to a car maybe? i would also recomend making the centre plate black so that absorbs the light energy rather than reflectibg it away, if you could give it a black anodising that could work great. Good luck!
First of all I would like to commend the meticulous work you have done. It's just fantastic problem solving ! I have few observations 1) the spherical mirrors should have been ok too because you are aiming for heating and non imaging application. The only requirement was that reflected sun rays must fall on aluminium collector and not miss it. 2) you need to apply some black absorbing material on aluminium having water pipes, which I guess you would be doing. 3) As I understand the acrylic mirrors have to direct and focus on some mirror which will reflect back that light to aluminum collector having water channel. Designing that will be more challenging as it is duplicate of your acrylic mirror design but with constraint of smaller dimension and more temperature capacity. 3) finally you need to keep appropriate flow rate in water channel to avoid steam formation. Goodluck to you However you must calculate the photo to thermal efficiency of your system and the benefit associated with it.
I have to say, it looks amazing :) I'm curious how effective it would be, but it seems like a great project and would want one for myself, so I think I'm going to steal your design when you're done :D Also, being a neighbor from the south, I feel your pain trying to test solar panels in the rain. much love from Belgium! you have my subscription
I enjoyed watching this very much. Many other comments have addressed my thought that each of your segments needed to be a different section of the parabolic curve (like on the JWST), but as many have said, this is only necessary to focus a sharp image. Looking forward to seeing video #2
awesome project. it's on my list for years now. 1. what if you molded the acrylic first and then put the silver foil on it? and did you check other foils, such as a rescue "blanket" or using real silver like they do for DIY telescope lenses? 2. the liquid for heating, I would have used oil as it goes easily to 300C without damaging or boiling. 3. what about a heat storage? a highly insulated barrel that stores all the energy and used when needed? 4. the solar tracking sensor: great! how did you solve that at the end of the day it goes back to the morning position? (otherwise it's impossible to find the sun when in evening position) 5. the aluminum disk you can easily ANODIZE in black. at home. that should last forever.
Some suggestions: Rather than try and bend the mirrors into shape, you could try Mylar and a vacuum to form a perfect parabola and focal point - no screws or heavy mirrors required. You could also make the mirrors a LOT larger. Mylar only reflects about 90% of light but making them larger (maybe to to the same weight) you''ll get a lot more overall energy. I presume the secondary mirror you mentioned (not shown) will be at the focal point and it's to reflect the light back to the heat exchanger. But that secondary mirror will need to handle about 7kw of energy - the same amount as the heat exchanger - it's going to get very hot, very quickly. A single reflector (array of articulated mirrors) will be easier to build and won't melt. So if you created an array of vacuum drum mylar mirrors each with 2 axis articulation and an adjustable vacuum - with some programming to relocate the focal point you will have a death ray.
I wish PCBway was located in a different country. I'm not allowed to do business with them. What a cool project. It would work well in my winter home in Paradise Valley Arizona.
a suggestion for building the mirrors: 1) 3d print a parabolic plate in plastic 2.a) spray it with a reflective paint 2.b) or tape aluminium length wise to cover the parabolic plate 3) cover it in epoxy resin to make it more durable a suggestion for the design: -instead of moving a huge and heavy mirror, focus smaller sized mirrors. (for example if the motor is reliable for 50 kg, instead of using a 75 kg mirror, use 4 smaller 40 kg mirrors) good luck and I hope this was useful
I love your project! I think the mirrors being identical and parabolic might not focus the sunlight as efficiently as possible. For a perfect focal point, the entire array might need a unique parabolic curvature across the structure, like the JWST design. That way, the mirrors would need to have 3 different types of curvatures instead of all being the same. Just a thought!
I would put the mirror foil on the smooth side *after* the molding phase, which doesn't have direct contact with the 3D-printed mold. You need to thinker more with the parameters for the "perfect" parameters of the mold, tiny deviatiations from the plexiglass contracting during cooldown will change the focal distance by a lot, you probably have to "overbend" them a little. I would also put the heating plate directly in front of the mirror array and run the water tubes inside 2 of the 3 pipes that would hold the plate in the focal point.
For your solar mirrors with the painted acrylic plates, I'd suggest using several layers of the paint, and then buffing the paint to give it a nice shine, then clear coat it to seal it. This would get around the dullness of the paint you showed in the video.
I'd use metal springs as well as mylar applied to the plexiglass after it has been shaped. If that aluminum plate is meant to heat the water then it should be painted, or better yet powder coated, matte black.
I would change a lot, but that would be complete rework Like investigating aluminum as mirror surface Using inflatable design pretty much balloon within balloon and could also use lift gas and attach everything with rope system But also had a lot of weight constraints, could get bigger for better lift of anything that's will get focused sun at
you can also take a plate of some sort, cover it with reflective plastic, and partially suck the air out from the plate which will create a vacuum and pull the plastic back a little leaving you with a perfect concave mirror
maybe a frame around each mirror that compresses each segment to a parabolic shape (it will need a back to hold shape) , this would remove the need for heating, also screws in the mirror face making the mirror a cleaner surface.
Pairing these "solar death rays" with a simple stirling heat engine, instead of needing a water pump and coolant lines going back and forth between energy generation and the death ray. Death Ray could instead be formulated to reflect light to the "hot end" of the Stirling engine which would directly translate heat energy to mechanical energy in the form of torque which could then be used to drive an electric generator.
You can use half of a large pipe cut along its length as a mirror. Then, you can place a copper pipe painted black, in the focal point of the large pipe, and just circulate water through it.
When making the solar water heater Try painting to black with "Mizzou black paint" and try to have it in a vacuum so it can't radiate the heat out I don't know if you can make a clear dome to use as the vacuum chamber... Actually I'm not sure if Mizzou black paint can we stand high temperatures... What you could do is get a candle and lighters and catch the soot coming off it to coat the disk or a glass pipe and put that inside a vacuum tube and find a glass worker to join the tubes, when it cools, it will have some vacuum not sure how much... Good luck
I'm certainly not an engineer. I'm a 3D artist in game development. But recently, at work, I needed to get acquainted with the design of large parabolic antennas for radio telescopes. I noticed that your mirror experiences a lot of shaking and jerky movements when lifting. It seems to me that this is due to the fact that its center of mass is located far from the axis of rotation of the lifting mechanism and lies somewhere in the center of the mirror. Because of this, the entire structure experiences uneven loads, which can affect the durability of the mirror adjustment mechanisms, as well as the motor and drive shaft of the lifting mechanism. Perhaps if you make a counterweight that would shift the center of mass of the mirror to the axis of rotation of the lifting mechanism, it will last longer and work more smoothly.
For better efficiency, you could do right now: - cover your aluminium dish with soot or with anything that is as black as possible (try avoiding thick coatings). I'm sure you know it yourself though, and you are just trying to invoke people leaving you comments :P for future: - another design for the light collector: if the light focusing is good enough, you could make the collector in a shape of a classic "black body" model, which is just a thermally insulated black-walled vessel with a lone hole for light input/output. In this case, you could minimize all three types of heat loss: conductivity, convection and thermal radiation - OR it's possible to use a clear/transparent thermos as a shell for your collector. This will prevent heat losses by air convection. This is also what Chinese use in their solar concentrators - those, which look like a row of glass pipes with a cylinder on top. - you can try to apply metallized film at the mirror face to increase reflectivity
10:50 you have shown that plexglass will deform under pressure at ~100C, so that backplate is certainly going to deform under the water/steam pressure at the temperatures this will run. You're going to have a ton of leaks, at least internally, pprobably externally too. Seeing the water circulationg is nice, but probably not economical unless you can use an acual glass sheet. Probably better to use aluminium or steel (or copper, see below) for the back plate. Aluminium also doesn't distribute heat well. While the recommendation to make the central collector black has been raised, I'd also reocmmend a copper cladding on the outer surface to distribute the heat evenly on the block to prevent local hotspots boiling your water. You can use computer thermal paste to get good thermal transfer to your aluminium block, and then paint the copper black (or just heat it up to 300C+ and let it oxidize in air - Copper II Oxide is matte black and temperature-stable). For the mirrors, you only need 6 different forms to make the whole mirror match one big parabolic mirror. Each of the 6 triangular sections of 6 panels can be rotated about the origin. For forming, vacuum presue may casue less problems with delmaination of the mylar then sandwich pressure. As an alternative, there are ways to electroplate platsics involving conductive paint, then plating copper, then silver. That might be possible post-forming, eliminating the stress cracking and buckling. Don't try to plate chrome, it's not worth your health despite being cheaper.
Don't know if it would work with spray paints, but back when I built and painted scale models and ttrpg figurines, you could buff and burnish metallic paints with fine cloth to get the surface a lot more reflective and looking like actual sheet metal.
Just finished the video I think the only thing that I would comment on is that for the mirrors if you need to get more reflective index we would use mylar sheets over the mirrors surface. My other concern is the aluminum heat plate, aluminum acts as a great heat sink so worry it may not be as efficient at keeping heat like steal would or another metal.
I assume that the aluminum heat plate should be coated in something like vanta black to better absorb light. Not sure if that particular pigment would withstand the temperature though, worth looking into to though
about the mirror, you shold FIRST bend the plexiglass and AFTER apply the mirror film, this avoid it to be damaged by hot of microwaves oven. anyway the project is amazing, i subscribed your channel!
3 points to make about this video. Gold or silver metal is something entirely different than spray paint. These panels aren't even fully reflective but partially trans-missive. No sun to measure with? So where does the end-shot come from?
I don't know but if you spray a 'clear' automotive coat on the gold and silver paint...this should reflect much more..! Nice build and research...Sir ~Regards and Namaste~
How many other mainland manufacturers have you tried apart from PCBway? A comparison would make for a great vid. As for the design, can you add a clockwork mechanism to replace the main motor please?
Great! what mirror film did you use? as it look transparent from behind. Did you try the mirror film used to grow weed indoor? may be it is more reflective. Impatient to see the efficiency measurements !
Cool project. Your collector is reflecting most of the light you worked so hard to dollect. You need to paint it plate mat black with a high temp paint. (Try automotive paint). This one change will probably 10x your efficiency.
3:24 Are those those metal probe temperature sensors? I bet they're going to reflect a good deal of the IR power. Pretty sure they're intended for conductive temperature sensing. You could insert them into some block of material that absorbs IR well like graphite or something. Oh, or maybe a layer of soot on it by holding it in a flame could work?
* If holding the probe in a flame doesn't break it that is. I think Robert Cowan has a video on a laser power tester that basically does this exact thing.
Great video, you mentioned that the heat is at the infrarred, do you have access to a thermal camera to confirm that? And I’m not just saying, I already did it and the result is shocking…
Your tracking system looks good and it's probably easy to do it digitally but it could actually all be done with a few op amps. One thing though about the heat collection. Your plate should be black to absorb as much heat as possible using black chrome or black nickel. And it should be a very heat conductive metal such as copper as well. Those tubes should be copper to transfer as much heat as possible. I even considered iron but that's not as good a heat conductor as copper or aluminum. I think it would be funny to grab an old iron frying pan (your plate looks about that size) and cut off the handle and braze the copper tubing to that. Solder might actually melt if your machine works. I've seen much smaller solar cookers and they get amazingly hot. A recessed collector or a semi-spherical collector is more efficient because it traps light and minimizes heat loss. Ask Chat GPT about this. I did and it gave me a lot more than I put here. Everything about this is subject to cost and ability to actually do it. I think since you already have an nice aluminum plate you should just keep that and coat it black and replace the tubing with copper. One thing that popped into my head is, how do you make aluminum black? Then it occurred to me that all you need is a cantle to coat it with soot. That's plenty black. Or paint it with black stove or BBQ paint.
I was thinking heat pipes, or evacuated solar collectors somewhere in the mix. Your set up is pretty awesome though and I love the reference to Webb. Regarding gold being a good IR reflector could you use polished brass? Oxidation could be avoided by spraying with transparent lacquer.
The sun at my Kalahari residence in South Africa will destroy the plastics within one summer! I'm thinking more in the lone of stainless steel mirrors and the rectangular parabolic mirrors.
Apply the reflective film after shaping the plastic....
Hard to apply flat sheet cleanly to a curved surface without creasing
@@taureviews if it's reflective tint, use a heat gun and soapy water, I promise it works.
Dido
@@taureviews People do it every day wrapping cars.
Its not you are wrong @taureviews
The heated aluminium disc should be dark, black (but not catch fire) to use enough of the light that is focused on it (as it's well known, the darker the object, the better it heats up).
And, I'm sure you've considered this, but just in case: of course each segment must be the shape of the corresponding part of a parabola, not of the parabola's centre.
If the focus point will be few centimetres above aluminium disk, trap for light could be made: second disk with small hole that will be few centimetres above main disk and aluminium wall between two disks. that way almost all light will get through the hole in the first disk and then rereflect many times inside our trap, heating everything up. This also will stop wind from cooling main disk. And of course all walls inside trap should be black - main disk heat resistant paint and other walls of the trap could be painted with black 3.0 to really boost performance.
@@MrMpakobec Поддерживаю
Not necessarily, if all parabolic mirrors (and their respective focal points) are equidistant to the secondary mirror/heater plate. It's way cheaper and faster to have one mold for all mirrors.
3d Printing 6 different forms (as it's rotationally symmetrical, you should be able to reuse them) probbably isn't too much overhead, but I'm not certain it's worth it. In case of remoulding, a vacuum attatched to the negative mold might pull the plates into shape without damaging the mirrors finish by compressing them from the top.
A more expensive option might be to get copper-clad plexiglass for the panels, form them and then electroplate them silver. The upside is you should be able to get a very eaven coat by placing the opposite electrode at the focal point of the mirror, so it's fairly equidistant from all points (minus the spherical/parabolic deviation) That would hopefully remove some of the waviness you have in your formed sections from the adhesive releasing and/or the film buckling.
Also needless to say, make sure if you paint the plate black, you use temeperature-resistant paint like the stuff the make to paint mufflers or barbecues. Probably need some sort of primer with it as well, although the more different layers you have the worse the thermal conductivity could possibly be.
Building all of this just to be hit with the reality that you live in the Netherlands is very relatable. It's like when me and me dad installed solar panel lights on our house and forgot we get an absurd amount of clouds, so we originally thought we bought defective lights XD
Send me a version for testing in SEA. I already have a neighbor with a similar set up who sells solar roasted chicken on the highway. I will send back a cut of the profits for further R&D.
Do you remember if they were the blue crystalline looking ones or the black ones with stripes? The blue ones have like 4 times the Amp output in relation to surface area but only in direct sunlight. The black ones will output under 4 inches of snow and clouds.
You need an optimisation for diffuse Licht ut would help
Since you're trying to catch the light on the big plate, the parabolic shape on your primary mirrors is unnecessary. Each petal or mirror segment can be flat and the secondary mirror can be flat; the parabolic effect will come from how each segment is focused on the secondary. Rather than throw a tiny hot spot onto the receiver, let it be bigger and heat the whole thing more-or-less evenly. Lower deltas are less lossy.
Also: you really want a dark receiver. Shiny silver will reflect a lot of the incident energy, shiny black will absorb it without re-radiating it so readily. Your ideal surface should be black chrome.
If he wants to achieve a real focus, each mirror should be a section of a paraboloid. Mirrors at the same radius can have the same shape, but the mirrors should be different shapes at different radius values.
I did something like this with a 1.2m satellite dish and aluminium foil, and then a mylar sheet over the dish and partially evacuated the volume behind - it was scary efficient!
I used candle soot to coat the bottom of a pan to absorb the energy.
At night, I could point it to a clear sky and use it to freeze things!
Yeah! The aluminum plate needs to be as black as possible. And not gloss black. Matte black
JWST needs parabolic mirrors to create an image, you do not have the same requirement: you just need all the light from a mirror to reflect on the collector. A plane mirror illuminated by the sun creates a reflection of the same size at most, so the only requirement is to have a collector of the same size of the mirror.
This is a good point, I think a solid compromise that would be especially effective here, is set a reasonable focal goal for the curvatures, small enough to splash the majority of the target for good transfer.
Partially true, but one thing to consider is that the efficiency of a solar heat collector is proportional to the temperature difference you can achieve, and you can get a larger temperature difference for the same size collector by concentrating the light using parabolic mirrors.
Yes, focusing to a point is unnecessary unless you want to melt things - key is to collect energy as heat more efficiently, not concentrate it more than is necessary.
The same energy can make a high temperature over a small area, or lower temperature over a larger area, and the latter may be more efficient by maximising heat transfer time to heat the fluid medium by the desired amount. There are a lot of things to consider.
Coating the collector with soot from a candle will also increase absorption.
I agree, I think for a V1 flat mirrors are fine. Parabolic mirrors should be an improvement as an upgrade for more efficiency.
@ No, flat mirrors only fine if the collector is where all the reflections impinge on it on the end of the boom.
There is no shape that can then reflect them all to the collector in the centre of the dish as they would all miss except one.
In this case they would need to be partially focused to land on a parabolic convex reflector to then land on the collector in the dish, with a suitable radius to provide a temperature enough to heat the water to the desired temperature.
Color isn't really a good indicator for reflectance of infrared light. Actual gold like the stuff used on the telescope would reflect much more light, because the spray paint uses stuff that looks like gold, but isn't, it probably reflects much less light.
Lasers (IR CO2) use gold mirrors, they work well enough up to about 50W. The coating is rather fragile. They're reasonably cheap but small, only 20mm.
Telescope dudes will sputter silver onto glass (say 300mm) easily enough, could probably point you towards someone who could do gold. These would have the coating on the front.
As someone who builds solar cookers I've never seen anyone at that level of engineering (except industrial projects). Very impressive and I also like the design👍Looking forward to part 2
Nah, he overcomplicates it. Keep it simple, that's the recipe of a good solar cooker :D
@@Sekir80 I agree, but it's always nice to see a different approach.
One glaring thing that may be a problem... the heat collector is currently reflective. Spray it matt black with heat resistant (stove paint) paint as it will absorb heat much better than the shiny surface.
Good one!👌
@@ConceptCraftedCreations dimple the surface like a golf ball before you paint it for more surface area.
@@ConceptCraftedCreationsThe fact you're using aluminum gives you an option for making it black:
There was research done stating that a simple candle's soot actually forms carbon nanotubes onto the aluminium surface.
Simply put, just soot the aluminium disc with a candle and gently have something transparent to protect it from the elements.
Used this for my solar space heater, works well, however haven't tested if simply painting it black has any difference. But theoretically the nanotubes would be perfect light capturers.
Maybe consider painting the collector plate black?
What is the energy loss of having a 2 mirror system vs having the alumnium plate take the direct reflection of the first mirrors?
More complicated piping I assume
@@p529. same piping. just put the plate into the focus point and its done.
@@jpjay1584 I'm assuming it's more about the weight of the heat plate versus a mirror than anything else.
Yeah, the ‘heat plate’ really should be at the focal point of the mirror array, instead of a double mirror.
The weight of the heating plate might be the main reason for the design choices here.
slewing bearing ok, but springs expensive?
xD
(I'm not American) My salary is less than $100 a month, however I recently allowed myself a set of 200 springs for $5 for the sake of 4 springs :)
But the springs can really be replaced with alternatives, and the bearing is specific and very important, I guess it's just the man was choosing what to spend money on and what is not worth it
@@broniusale5987 Yeah, I don't understand what that was about either. Just looked at temu, searched for springs: springs galore for 10 to 20 ct a piece.
@@MartinMaat don't promote cancer temu. it's a bloatware to the economics and healthy market.
test the springs at different temps, cause they might lose their strength when hot from the mirrors
Instead of allowing the water to flow through the collection plate under acrylic, I would of put copper tubing and soldered it into place to make better contact. Better contact allows for more efficient transfer of thermal energy. Also, the water will get very hot and start to build up pressure which can cause the acrylic to start to flex under the pressure, plus the heat making it softer.
On my single solar thermal collector I had on a 2ftx4ft panel, the water would start boiling before exiting the system, which led to a lot of a air locking keeping the water from flowing smoothly. The system *had* to run under pressure to keep the water from boiling so easily.
Yeah, that acrylic backplate is just begging for leaks. The mirror tests already show it can significantly flex at 100C, and there's going to be a lot of water/steam pressure in there.
I suggested in another comment that a car radiator would be a better collector.
Very good project.
1. Place the heat receiver on the rods, and not reflect the light twice, which only leads to double losses due to light reflection.
2. Paint it black or smoke it with soot. 3. It is possible to apply a reflective coating after forming the bend of the mirror, in order to avoid cracks when heated.
4. Add a protective layer on top of the reflective one, since it is difficult to maintain the integrity of the coating in the sun, wind and rain. Plus, the second layer can be polished with a car polishing machine.
5. Replace tracking by lighting level with a simple table of the sun's location by time of day (but then you need to add potentiometers or decoders to the rotary axes).
6. If you want to leave the installation outside for a long time, you need to add a protective function to avoid strong winds, add a wind sensor or simply take information from the local weather forecast (mirrors are just a big sail)
I agree with all but #5
Gold paint ≠ gold reflectivity
Silver paint ≠ silver reflectivity
At least outside of the visible spectrum. Paint just looks the part -it's optical properties are totally different to precious metals and also different to whatever coating is on your plastic mirrors.
6:58 missed opportunity to give a gold medal to silver and a silver medal to gold.
Yeah, I thought there was no way you could finish the whole project in only a 13 and a half minute video. Well, you are almost done. Can't wait for part two!
Glad you enjoyed it! Part 2 coming soon🤓
Issue, their is a maximum amount of energy a solar panel can convert, in fact as the solar panel heats up the conversion rate of the crystals drop. Layered solar panels with water cooling is now a better method to increasing the energy efficiency. So focusing on less solar panel material probably won't help much unless your in winter.
I like the mirror segmented, easy to replace if any damaged, allowed fine tuning, and cheap compared to a giant curved mirror. Nicely done
The only thing I would have done differently is just make one huge parabolic instead of segmented ones. I also would like to see how it's going to be used because I'm having trouble understanding how other than just heating water what use is it? granted heating water is pretty useful too.
Humanities scientific advancement is pretty much measured by how complicated a way we can devise to boil water.
home made solar water heater powered by a fresnel lense
th-cam.com/video/rrGMidc_P7s/w-d-xo.html
One huge mirror is more difficult to make. That's why the Webb uses that hexagons. Of course, individual mirror segments have their own issues....
Easier to replace a single failed mirror from an array, rather than having to replace the whole thing.
Also easier to make small mirrors than big ones
Also easier to correct for flaws etc with small mirrors than one big one.
There are some advantages to a solid mirror. There are some advantages to a mirror array. 🤷♂️
If you point it at a solar panel you can get a lot of power out of it. Most aren't rated for that level of power though so for consumers a heat based generator might be more plausible
Did you apply the paint at the front of the acrylic panes? It wasn't clear to me, it would be best to apply it at the back like with any mirror. Then the aluminium core plate must be painted matte black of course, you do not want that to act as a mirror too. I expect some issues with boiling, tubes may burst or come off. You may need to control the water flow based on the plate's temperature, making sure it won't exceed 90 degrees Celcius or so. And using astronomical data tables for your date and location seems more effective than trying to figure out where the sun is in real time. This is how all trackers for solar panels work. Overall I am impressed once again.
Yeah, he's going to need a lot of water pumping through that block to keep the sink below boiling temperature, which means needing a constant use for the hot water. Recycling got water will also make it boil.
Honeslty, being able to form the plexiglass mirrors at 100C means getting any where close to boiling will cause the seals around the plexiglass backplate to pop. The tempreature and constant water/steam pressure will warp it.
Paint the heat collector black, as silver reflects...no need for individual curved mirrors, as the current setup uses low reflectivity film. Rather user real flat mirrors and get all reflections from the flat mirrors to overlap on the heat collector. More smaller real mirrors may be the way to go.
I think you should create a solar tracker that only requires grid coordinates and a calendar to operate. With those two pieces of information, one should be able to create a platform for solar collectors that is 100% accurate without worrying about it being exposed to the sun.
Using windows tint should allow you to apply it to the curved acrylic AFTER shaping.
There is a technique using heat guns that tint shops use to shape the film to curved surfaces.
I believe this would allow for a cleaner/smoother surface finish, thereby a more efficient system.
If the mirror puts a large strain on the tilt motor, could you add a counterweight to balance it?
Theoretically that would be possible yeah!👌
great comment! all gimbals are balanced.
Amazing project, choosing foil on Plexiglas with foil as reflectors....well its cost effective.
The bigger problem i see is with using Plexiglas as the back cover for the heat collector.
Years ago i tryed to build watercooling blocks from Plexiglas and found out it gets very soft around 60C already, making the seals leak because the skews loose pressure cuz they sink into the plexi.
I don't really understand the spherical/parabola difference in your application: why are you so concerned to focus the light into one point (parabola) instead of leaving it a bit spread out (spherical) if you use a gigantic solar collector (aluminium plate)? By the size of the collector the hexagonal patterns could even remain flat.
Another thought: you should have just bought a satellite dish second hand and coat that one. Easy, no?
Great Idea! For the Parabolic Curve. . . You could just Keep the Mirrors Flat Since they already Follow a parabolic curve. Otherwise Each Mirror would have to Have the Individual Corresponding Curve for that Segment of the Overall Parabola of the Dish. Without that Exact Arrangement you will loose Light Density, I personally believe Flat Mirrors Arranged along the Parabolic Curve would Give an Overall Higher Density of Reflected Light though not 100 percent.
That's what I was thinking. I'm sure there are quite a few scientific journals on what's best. there's no need to reinvent the wheel with how much effort is being put into it.
the focus points would be too big but yes its easier to do.
try to cover the heat plate in something extremely dark. Maybe soot for a simple solution, or vantablack (or similar) if they can withstand the heat. That should absorb nearly all the light energy
LOL, I love the sad teddy laying face down in the lane. speaks to the moment !!
Very good quality of video overall, no junk or filler.
As for tilting mechanism, consider redesigning it. Main problem with current iteration is that it is relatively weak. It may hold light frame with reflectors, but then it'll need to be strong enough to withstand the winds. And winds will potentially double or tripple the loads.
rub the aluminum disk with really fine grit sandpaper and then rub some artist charcoal all over it.
Is that also heat resistant that you know of?
@@ConceptCraftedCreations I'm sure that because the charcoal is carbon it would combust easily especially as a powder.
@@ConceptCraftedCreations since it's pretty much pure carbon, it shouldn't burn, but should increase the amount of light energy being absorbed into the aluminum. You could also just hold the sun facing side of the aluminum over a campfire until it collects a good coating of soot.
@@ConceptCraftedCreations anodize it. DONE!
Really interesting project. My thoughts. Gold paint and gold are obviously different but that’s not important as cost is a factor. You could try using aluminium foil or even “speed tape” (aluminium tape). I don’t think using parabolic mirrors is important if the overall shape is parabolic. You’re just trying to focus the light onto the central mirror and then onto the heat collector. The central mirror may need to be parabolic to focus the energy roughly onto the collector.
Why not just stick small mirrors onto a TV dish and try that. Much cheaper especially if you get a scrap one. The dish and mounts are also designed to work in high winds but the weight will mean larger motors and you may need to use a counterbalance to help lessen the load on any motors.
I'm guessing the JWST used a gold coating because it is good at reflecting IR, because imagining in the IR spectrum is what the JWST's main mission is.
Why you chose paint insted of space blanket? I think second can be more effective
But anyway project looks cool
I would put the collector at the 1st focus and make it a sphere with a hole in the side to let the light in and stop any reflections from leaving.
Imagine machining channels into a hollow sphere with a hole in the side, then coat the inside with candle soot.
This way, you won't have to worry about machining a secondary mirror. The parabolic segments reflect just once through the hole in the sphere and everything is captured.
I made a solar tracker using an Arduino, GPS module and two servos, (later two steppers) and some code to translate time of day and lat/long location into elevation and azimuth in degrees.
Works even when overcast. Add an anemometer then set to elevation to 90° if wind exceeds a limit.
Use a linear actuator for elevation - this can take a lot of load. Raise the dish and add a counterweight to reduce static torque.
Servos are a pain - they want to slew suddenly to another position at power-on, and that can break things if they don't have a clutch mechanism!
2:07 graphite paint and gold/nickel plating
or mylar and vacuum to shape it.
5:54 diy spring with welding wire.
So, you've made a solar concentrator that was invented over 2 millenia ago. There are even modern versions that use molten salts instead of aluminum. I think you should have done more investigation on what has already been done. There are even studies about the best materials to use as receivers. This is inventing in a bubble.
Sometimes if you invent 'in a bubble', you may come up with something new and better than what was done previously, that said examining what has gone before can be helpful and shortcut the design process. Pointless to reinvent the wheel but you could invent something that does the same job but better? Besides he did look at the JWST design for inspiration.
That's so cool. I think that the segments should be offset paraboloids. Also i wonder what geometry does the secondary mirror has
This is a cassegrain antenna design. The formulas are all over the antenna design websites. It is very critical though. and actually you usually want to focus in a single point but for this you should try for a focal point past the plate just where the cone of light would evenly cover the plate.
12:56 killed me !
Amazing project! Lookinf forward fo the results
Anything I would have done? Not use gold and silver paint for one. When it comes to energy, paint is not the same as the actual materials; it's a case of pigment versus metallic elements. Sure, I get that neither one is cheap, but you can only go so far with just substitutes.
I get what you mean! What's your opinion on the test with the laser to test reflectivity if i may ask?
@@ConceptCraftedCreations Seemed accurate enough to me, so kudos on that. Seriously though, real silver mirrors will beat just about any substitute in this kind of situation.
@@ConceptCraftedCreations Gold paint, isnt the same color, nor reflectivity, of high purity Gold. For that test, you should use Gold-Leaf. Gold Leaf, is real gold.. just incredibly thin... making it semi-affordable, for coating things like Picture Frames.
You should get a light gray projection sheet or paper to put down on your table when you're using your projector like this, it'll increase contrast and color, as well as reducing reflectivity from the surface as it stands.
Black automotive paint on the heat collector would likely help a lot. Protects the part from weather and increase heat absorption. A rough finish would increase the surface area as well by the tiniest bit to collect as much as possible.
have you thought about using a "black body box" collector instead of the plate?
Tip. Have a look at a polar aligned equatorial wedge.
You will find tracking easier as all the tracking for the day can be done with one motor running at 1/24 revolution per hour.(the earth is rotating not the sun moving)
Why is the disk in the middle silver it will reflect heat & light, it should be the darkest matt black you could find.
id reccomend applying the reflective film after shaping if possible, a heat gun may help with this like applying a wrap to a car maybe? i would also recomend making the centre plate black so that absorbs the light energy rather than reflectibg it away, if you could give it a black anodising that could work great. Good luck!
A gas strut would help take the weight off the hinge.
First of all I would like to commend the meticulous work you have done. It's just fantastic problem solving ! I have few observations
1) the spherical mirrors should have been ok too because you are aiming for heating and non imaging application. The only requirement was that reflected sun rays must fall on aluminium collector and not miss it.
2) you need to apply some black absorbing material on aluminium having water pipes, which I guess you would be doing.
3) As I understand the acrylic mirrors have to direct and focus on some mirror which will reflect back that light to aluminum collector having water channel. Designing that will be more challenging as it is duplicate of your acrylic mirror design but with constraint of smaller dimension and more temperature capacity.
3) finally you need to keep appropriate flow rate in water channel to avoid steam formation.
Goodluck to you
However you must calculate the photo to thermal efficiency of your system and the benefit associated with it.
I have to say, it looks amazing :) I'm curious how effective it would be, but it seems like a great project and would want one for myself, so I think I'm going to steal your design when you're done :D Also, being a neighbor from the south, I feel your pain trying to test solar panels in the rain. much love from Belgium! you have my subscription
You deserve more subs and views, a very fun project and video
I enjoyed watching this very much. Many other comments have addressed my thought that each of your segments needed to be a different section of the parabolic curve (like on the JWST), but as many have said, this is only necessary to focus a sharp image. Looking forward to seeing video #2
awesome project. it's on my list for years now.
1. what if you molded the acrylic first and then put the silver foil on it?
and did you check other foils, such as a rescue "blanket" or using real silver like they do for DIY telescope lenses?
2. the liquid for heating, I would have used oil as it goes easily to 300C without damaging or boiling.
3. what about a heat storage? a highly insulated barrel that stores all the energy and used when needed?
4. the solar tracking sensor: great! how did you solve that at the end of the day it goes back to the morning position? (otherwise it's impossible to find the sun when in evening position)
5. the aluminum disk you can easily ANODIZE in black. at home. that should last forever.
Some suggestions: Rather than try and bend the mirrors into shape, you could try Mylar and a vacuum to form a perfect parabola and focal point - no screws or heavy mirrors required. You could also make the mirrors a LOT larger. Mylar only reflects about 90% of light but making them larger (maybe to to the same weight) you''ll get a lot more overall energy.
I presume the secondary mirror you mentioned (not shown) will be at the focal point and it's to reflect the light back to the heat exchanger. But that secondary mirror will need to handle about 7kw of energy - the same amount as the heat exchanger - it's going to get very hot, very quickly. A single reflector (array of articulated mirrors) will be easier to build and won't melt.
So if you created an array of vacuum drum mylar mirrors each with 2 axis articulation and an adjustable vacuum - with some programming to relocate the focal point you will have a death ray.
mylar on it's own is already more reflective than the mirror tint he's using, so this is a good suggestion.
Make sure to keep it secured when the wind picks up. Thank you for the cool video!
This guy is putting a lot of work in his videos, make sure to leave this video a LIKE!
When you said the springs were expensive my mind immediately jumped to TPU printed springs! What a great watch.
I wish PCBway was located in a different country. I'm not allowed to do business with them. What a cool project. It would work well in my winter home in Paradise Valley Arizona.
a suggestion for building the mirrors:
1) 3d print a parabolic plate in plastic
2.a) spray it with a reflective paint
2.b) or tape aluminium length wise to cover the parabolic plate
3) cover it in epoxy resin to make it more durable
a suggestion for the design:
-instead of moving a huge and heavy mirror, focus smaller sized mirrors.
(for example if the motor is reliable for 50 kg, instead of using a 75 kg mirror, use 4 smaller 40 kg mirrors)
good luck and I hope this was useful
I love your project! I think the mirrors being identical and parabolic might not focus the sunlight as efficiently as possible. For a perfect focal point, the entire array might need a unique parabolic curvature across the structure, like the JWST design. That way, the mirrors would need to have 3 different types of curvatures instead of all being the same. Just a thought!
I love the raw honesty. What great video. Thank you
I would put the mirror foil on the smooth side *after* the molding phase, which doesn't have direct contact with the 3D-printed mold. You need to thinker more with the parameters for the "perfect" parameters of the mold, tiny deviatiations from the plexiglass contracting during cooldown will change the focal distance by a lot, you probably have to "overbend" them a little. I would also put the heating plate directly in front of the mirror array and run the water tubes inside 2 of the 3 pipes that would hold the plate in the focal point.
For your solar mirrors with the painted acrylic plates, I'd suggest using several layers of the paint, and then buffing the paint to give it a nice shine, then clear coat it to seal it. This would get around the dullness of the paint you showed in the video.
I'd use metal springs as well as mylar applied to the plexiglass after it has been shaped. If that aluminum plate is meant to heat the water then it should be painted, or better yet powder coated, matte black.
😂 I love the big reveal. You open the barn door and it’s cloudy and rainy out.😢
I would change a lot, but that would be complete rework
Like investigating aluminum as mirror surface
Using inflatable design pretty much balloon within balloon and could also use lift gas and attach everything with rope system
But also had a lot of weight constraints, could get bigger for better lift of anything that's will get focused sun at
you can also take a plate of some sort, cover it with reflective plastic, and partially suck the air out from the plate which will create a vacuum and pull the plastic back a little leaving you with a perfect concave mirror
maybe a frame around each mirror that compresses each segment to a parabolic shape (it will need a back to hold shape) , this would remove the need for heating, also screws in the mirror face making the mirror a cleaner surface.
What a great project!
Thanks! Appreciate it🙌
Pairing these "solar death rays" with a simple stirling heat engine, instead of needing a water pump and coolant lines going back and forth between energy generation and the death ray. Death Ray could instead be formulated to reflect light to the "hot end" of the Stirling engine which would directly translate heat energy to mechanical energy in the form of torque which could then be used to drive an electric generator.
You can use half of a large pipe cut along its length as a mirror. Then, you can place a copper pipe painted black, in the focal point of the large pipe, and just circulate water through it.
pipe is circular, its not efficient. needs a parabolic shape but YES, thats an easy way to generate heat.
When making the solar water heater
Try painting to black with "Mizzou black paint" and try to have it in a vacuum so it can't radiate the heat out
I don't know if you can make a clear dome to use as the vacuum chamber...
Actually I'm not sure if Mizzou black paint can we stand high temperatures...
What you could do is get a candle and lighters and catch the soot coming off it to coat the disk or a glass pipe and put that inside a vacuum tube and find a glass worker to join the tubes, when it cools, it will have some vacuum not sure how much...
Good luck
The collector plate needs to be all aluminum with a sealing gasket. The near boiling water will deform the acrylic backplate and cause leaks.
Most likely. I used acrylic glass in a DIY solar heater before, it expanded and deformed 😬
Size was about 0.5m², temperature about 100°C
I'm certainly not an engineer. I'm a 3D artist in game development. But recently, at work, I needed to get acquainted with the design of large parabolic antennas for radio telescopes. I noticed that your mirror experiences a lot of shaking and jerky movements when lifting. It seems to me that this is due to the fact that its center of mass is located far from the axis of rotation of the lifting mechanism and lies somewhere in the center of the mirror. Because of this, the entire structure experiences uneven loads, which can affect the durability of the mirror adjustment mechanisms, as well as the motor and drive shaft of the lifting mechanism. Perhaps if you make a counterweight that would shift the center of mass of the mirror to the axis of rotation of the lifting mechanism, it will last longer and work more smoothly.
For better efficiency, you could do right now:
- cover your aluminium dish with soot or with anything that is as black as possible (try avoiding thick coatings). I'm sure you know it yourself though, and you are just trying to invoke people leaving you comments :P
for future:
- another design for the light collector: if the light focusing is good enough, you could make the collector in a shape of a classic "black body" model, which is just a thermally insulated black-walled vessel with a lone hole for light input/output. In this case, you could minimize all three types of heat loss: conductivity, convection and thermal radiation
- OR it's possible to use a clear/transparent thermos as a shell for your collector. This will prevent heat losses by air convection. This is also what Chinese use in their solar concentrators - those, which look like a row of glass pipes with a cylinder on top.
- you can try to apply metallized film at the mirror face to increase reflectivity
lucky not to get asleep before such a fabulous vid.
This is an amazing content!! Congratulations!! I don’t know how I didn’t find your channel before
great work dude
Thanks man!🙌 Appreciate it!
I loved your idea of explaining things projecting on the table 👏🏻
10:50 you have shown that plexglass will deform under pressure at ~100C, so that backplate is certainly going to deform under the water/steam pressure at the temperatures this will run. You're going to have a ton of leaks, at least internally, pprobably externally too. Seeing the water circulationg is nice, but probably not economical unless you can use an acual glass sheet. Probably better to use aluminium or steel (or copper, see below) for the back plate.
Aluminium also doesn't distribute heat well. While the recommendation to make the central collector black has been raised, I'd also reocmmend a copper cladding on the outer surface to distribute the heat evenly on the block to prevent local hotspots boiling your water. You can use computer thermal paste to get good thermal transfer to your aluminium block, and then paint the copper black (or just heat it up to 300C+ and let it oxidize in air - Copper II Oxide is matte black and temperature-stable).
For the mirrors, you only need 6 different forms to make the whole mirror match one big parabolic mirror. Each of the 6 triangular sections of 6 panels can be rotated about the origin. For forming, vacuum presue may casue less problems with delmaination of the mylar then sandwich pressure. As an alternative, there are ways to electroplate platsics involving conductive paint, then plating copper, then silver. That might be possible post-forming, eliminating the stress cracking and buckling. Don't try to plate chrome, it's not worth your health despite being cheaper.
Your test setup is amazing
Don't know if it would work with spray paints, but back when I built and painted scale models and ttrpg figurines, you could buff and burnish metallic paints with fine cloth to get the surface a lot more reflective and looking like actual sheet metal.
Just finished the video I think the only thing that I would comment on is that for the mirrors if you need to get more reflective index we would use mylar sheets over the mirrors surface. My other concern is the aluminum heat plate, aluminum acts as a great heat sink so worry it may not be as efficient at keeping heat like steal would or another metal.
I assume that the aluminum heat plate should be coated in something like vanta black to better absorb light. Not sure if that particular pigment would withstand the temperature though, worth looking into to though
about the mirror, you shold FIRST bend the plexiglass and AFTER apply the mirror film, this avoid it to be damaged by hot of microwaves oven. anyway the project is amazing, i subscribed your channel!
3 points to make about this video. Gold or silver metal is something entirely different than spray paint. These panels aren't even fully reflective but partially trans-missive. No sun to measure with? So where does the end-shot come from?
I don't know but if you spray a 'clear' automotive coat on the gold and silver paint...this should reflect much more..!
Nice build and research...Sir
~Regards and Namaste~
nice project, i have been considering making something like this myself, nice video and im looking forward to seeing the next
Very nice build! Lots of great information!
Would love to see a vid on how to build the solar tracker itself to control the larger table. Would be fantastic for small solar arrays.
Springs aren't cheep?!? Wft!?!
How many other mainland manufacturers have you tried apart from PCBway? A comparison would make for a great vid.
As for the design, can you add a clockwork mechanism to replace the main motor please?
Great! what mirror film did you use? as it look transparent from behind. Did you try the mirror film used to grow weed indoor? may be it is more reflective. Impatient to see the efficiency measurements !
I love your videos. Always so informative.
Cool project.
Your collector is reflecting most of the light you worked so hard to dollect. You need to paint it plate mat black with a high temp paint. (Try automotive paint). This one change will probably 10x your efficiency.
3:24 Are those those metal probe temperature sensors? I bet they're going to reflect a good deal of the IR power. Pretty sure they're intended for conductive temperature sensing. You could insert them into some block of material that absorbs IR well like graphite or something. Oh, or maybe a layer of soot on it by holding it in a flame could work?
* If holding the probe in a flame doesn't break it that is.
I think Robert Cowan has a video on a laser power tester that basically does this exact thing.
Great video, you mentioned that the heat is at the infrarred, do you have access to a thermal camera to confirm that? And I’m not just saying, I already did it and the result is shocking…
Don't say that and don't share what you know😋 Because now I want to know what you know😅 Want to share it?
Your tracking system looks good and it's probably easy to do it digitally but it could actually all be done with a few op amps. One thing though about the heat collection. Your plate should be black to absorb as much heat as possible using black chrome or black nickel. And it should be a very heat conductive metal such as copper as well. Those tubes should be copper to transfer as much heat as possible. I even considered iron but that's not as good a heat conductor as copper or aluminum. I think it would be funny to grab an old iron frying pan (your plate looks about that size) and cut off the handle and braze the copper tubing to that. Solder might actually melt if your machine works. I've seen much smaller solar cookers and they get amazingly hot. A recessed collector or a semi-spherical collector is more efficient because it traps light and minimizes heat loss. Ask Chat GPT about this. I did and it gave me a lot more than I put here. Everything about this is subject to cost and ability to actually do it. I think since you already have an nice aluminum plate you should just keep that and coat it black and replace the tubing with copper. One thing that popped into my head is, how do you make aluminum black? Then it occurred to me that all you need is a cantle to coat it with soot. That's plenty black. Or paint it with black stove or BBQ paint.
I was thinking heat pipes, or evacuated solar collectors somewhere in the mix. Your set up is pretty awesome though and I love the reference to Webb.
Regarding gold being a good IR reflector could you use polished brass? Oxidation could be avoided by spraying with transparent lacquer.
Neat project! What are you using to laser cut the acrylic sheets, CO2 laser?
Very cool project. Or should I say, very hot project.
😄.. I'm happy you enjoyed it!
The sun at my Kalahari residence in South Africa will destroy the plastics within one summer! I'm thinking more in the lone of stainless steel mirrors and the rectangular parabolic mirrors.