DIY Solar Power

I wonder if you could take an old satellite dish (the 4 or 5 foot ones, should be cheap, even free) and coat it with a reflective material. It should be possible to boil water at the focal point. As one of the posted comments on youtube noted however, I think it would be difficult to convert this steam to electrical power. You would likely gain more to just use this hot water/steam for heating and just pay for the electricity.

Having a small steam generator would be very neat though; build it like an old steam engine and it would be an interesting showpiece. You could even run it with a woodstove in the winter!
 
The Fresenel lenses are available the DIY LCD projector fraternity use them
in their custom enclosures..Here's a link to the Lumen Labs Products page
 
A guy here in town made an old large dish clad in used CD's for the reflective surface. New blanks would probably be more efficient and are cheap. The thing worked pretty well from what I remember (fairly durable too). It's probably enough to run a stirling engine. I know a commercial company was running stirlings from a much larger dish for third world applications. I didn't follow them to see how it worked out. But the prototype units worked Ok. I'd say tracking the sun is the biggest drawback to this kind of idea.

As far as solar charging I made a set up from two 90 watt Matrix solar panels that charges a lifeline AGM. With an inverter it will partially charge my motorcycle or fully charge an eGO cycle on a good days sun exposure. Pretty expensive as chargers go though about $1200 total. It makes a nice demonstration unit though.

Aerowhatt
 
I saw a tv show where a guy had taken some mirrors and focused a hundred square feet or so of sun onto 10 square feet of solar panel, increasing the output of the panel dramaticly. The problem with this one was keeping the mirrors moving to keep the beam on the panel during the whole day. This guy had a whole mechanisim tied to a computer to do this. Easy for him I guess, but too hard for me. Anyway focusing some more sun seems to be the only real answer to getting solar cheaper with off the shelf stuff we have today. Short of that sort of thing, mounting your panels on a tracking mount really gives more watthours per day, but I don't know if it is cheaper than more panels, or just takes up less space where that is the issue.
 
DIY solar sounds interesting. One of the members here, mace1934, has a website which might interest you. This page details his process for charging an A123 pack with solar cells.

http://ruthnlarry.net/evs/bikes/26650/solchg.htm

Good luck!
 
As an alternative to solar power, I ran accross this the other day. Looks like an interesting concept.

http://www.popularmechanics.com/technology/industry/4224763.html


.
 
I like that belt idea. That is really cool. Not enough to power the bikes we use, but small amounts of power for nearly nothing is good.

For the ideas about using a focusing dish on a solar panel, couldn't you just have a dish on a panel that follows the sun? There is a guy that lives in my county that designs those tracking systems. I briefly met him at the local electric auto association here. He had some pretty good ideas too.
 
That would work, the tracker mount would keep the dish aimed. I just don't know if it would really produce power that much cheaper than simply filling the tracker mount with more panels. Once you scale up to steam turbine size, the mirrors are the way to go. I have found Home Power magazine online a really good source of what people have actually done, how it worked, what it cost, etc. When you see concentrating solar there, you know it has been found practical by somebody. All we really need is $2.00 per watt solar panels to make the home PV setup practical. A tax credit of 50% instead of 30% would make it affordable. I think it would be a better investment than a war in the middle east.
 
I am a huge fan of concentrators
DIY I would definitely go steam to generator.
This link has come up before:
http://www.greensteamengine.com/
2_cyl_1a.gif


And for tracking your trough or dish, the easiest system I have seen so far is just a drip water system. Big bucket with a hole (adjustable spigot) where as the water drips away the spring-loaded system pulls the troughs from facing east to facing west each day.

Apparently Abel had no problem running his printing press off of solar 106 years ago:
View attachment Press.jpg
tks
LOc
 
There are a whole series of videos on youtube about how to make dishes under the heading GreenPowerScience for example:
http://www.youtube.com/watch?v=23kkZZN1ACs
 
Welcome to the Sphere, diysolarpanels, and thanks for the links.
 
I always dream about building my own solar stirling generator, because they're much more efficient than solar panels in direct sunlight and relatively simple to build. I also thought of a large fresnel lense or a satellite dish mirror tracking the sun, so the focusing spot would always be on the piston. I know they already built large stirling dishes (Stirling Energy Systems did for example), but to build a small one on my own would be too cool!
 
Here's an option from the Hot Air Engine Society files. The smallest available turbo I've found is the Mitsubishi TD-02. If you're interested in home-scale ORC, here's a couple more links. (PS, if you are concerned a turbine might not work well, or is hard to source, you can modify a small one-cyl air-compressor to work as a uni-flow steam-engine like the Keveney-CO2-Motor):

http://www.animatedengines.com/co2.shtml

http://www.redrok.com/images/sterl2hp.jpg

http://www.popularmechanics.com/science/earth/4232571.html

http://tech.groups.yahoo.com/group/HotAirEngineSociety/
 
paul, i was not pleased with the guy spamming this thread "Welcome to the Sphere, diysolarpanels, and thanks for the links."

one of his links tried to infect me when i went to delete the page. i consider the guy a virus source and was gonna flag him so people should be careful of his links. he does not look like an ES member to me. anonymous too.

i think PV solar is more middle class hype. buy something to fix some current social fad.

rather than build solar panels, people should just terminate all useless electrical consumption.

this house has 3 girls and me, total of 270kWh last month, 60% of that is for the 2 refrigerators. so it can be done.

the most cost effective solar is solar hot water. very simple to do, is permanent, and will provide more power from the sun than PV and for 10% of the costs. passive solar heating is even more effective.

if someone is going to need PV, like in remote locations, especially in rural and underdeveloped countries, then it makes sense, but a connection to the grid is cheaper power by far. if you wanna avoid the meter fees, you can form a cooperative with your neighbors to split power service, and run cables from the one house to the others and meter each privately.

if you have already removed high current devices like dryer, range and oven, electric water heater, and other loads which require more than 20A then you can get away with running 12G service to each location. then if each house can cut back into the 300kWh/mth range the main service panel will handle all the load. then use propane or NG for the thermal source.

you would save enuff that way to pay for a lot of improvements too. but here the meter charge is only about $6/mth, still 20% of the bill.
 
LOCK, I will not quote your thread of two-above, no need. It's outstanding, esp. for your having found the antique engraving of a solar-fired parabolic-focused heat engine.

And this thread: this is my first lookie at this thread. MUCH READING to do.

I have only this little bit to offer, that the LTD "Stirling" is a relatively new variant on the ancient heat engine,
and it is cute as hell, and produces no usable power output in this form, but will run, literally, for many years, non-stop,
setting atop any slightly warm or cool surface. They are heat pumps, in effect. I love heat engines.

Here are a couple of mine, both viddies are home-made of factory-produced models: one is LTD and one is HTD:

Please "HQ" if you can; the crude videos are much clearer in "HQ" mode.

[youtube]ldN1xdS3iRA[/youtube]

[youtube]1S1-oD_pvSU[/youtube]

The high temperature differential heat engine can actually do WORK, even on a tiny scale:
[youtube]-I582ha_W7M[/youtube]

[youtube]aKg6IBH8j1I[/youtube]
It's all a matter of scale: toys are real, working machines.
Here I "grind" poppy seeds, just like two hundred years ago,
in miniature. Fun-value only, food for thought, and good for hamburger buns :lol:
 
the swedish navy uses a sterling engine to power the generators that charge the batteries in their diesel subs while submerged, and run the equipment. it is powered by burning liquid hydrogen and liquid oxygen which vents off and the gas phase is burned to make heat for the sterling engine and water for the crew.

they used the sterling engine because they could keep it acoustically silent.
 
I've got a small model of a stirling engine which I put behind a A4 Fresnel lens (got a bigger one though).The principle is so simple! Here's a vid (please excuse the bad video quality):

[youtube]GdRAnb3kg9E[/youtube]
 
A solar Stirling is one of my pet interests. I believe there are two reasons we don't see more Stirling engines. First, a 1kW Stirling will be 5 times bigger and twice as expensive as a gasoline generator. The other reason (IMHO) is, why would any businessman invest in building a product that so easy to copy? Here's my favorite example:

A retired British tinkerer made a triple-Beta boat engine. It makes its best power with a propane flame and water-cooling, but It will work with a wood-fire and an air-fan. The power-cyclinders are from a 1600cc VW bug engine.

http://www.geocities.com/wastewatts/boatpage.html
 
what about boiling water and putting the steam through a pump connected to a motor? stirling engines are too complicated.

low power pumps can be had on ebay for $10. brushed motors for $20. then all you need is to work out how to configure the boiler vessle.
 
A Stirling engine works with any temperature differential. Steam requires condensation and heat rejected at <100C else there is a large drop in efficiency. And the latent heat in a boiler is dangerous, in a pressurized boiler even more so as it will flash into a large volume of steam if a pipe breaks. Boilers with gauge pressures above 1 atmosphere are regulated in most countries and require expensive periodic inspections, e.g. http://www.qp.gov.sk.ca/documents/English/Regulations/Regulations/B5-1R1.pdf

Oddly enough ammonia heat engines seem to be mostly unregulated. I guess few mad scientists experiment with them anymore.
 
http://www.otherpower.com has a forum for DIY steam-generators http://www.fieldlines.com/hotlist/add/2009/5/23/134345/328/section//steam. DIY solar-steam is possible, but for a given power, ORC (freon steam) is easier and cheaper. That is if you want to condense the vapor and re-use it (more efficient, less heat for total watts generated because you're boiling hot fluid instead of cold fluid), however...

Its pretty simple to make a total-loss system. Boil water with free wood, run the steam through a uniflow one-cylinder from a converted air-compressor, and the exhausted steam just vents to atmosphere. Can't get much cheaper and easier than that. For solar steam, concentrator would have to be VERY large. Have fun...
 
Steam engines require lots of maintenance. The well engineered free piston solar stirlings can run decades with nothing more than cleaning the mirrors of the collector. That's possible because they consist of 1 moving part, and the gas bearings means there's nothing to wear. Don't forget that includes the generator portion, which is spitting out perfect sine wave AC at 50hz or 60hz or whatever frequency is designed in.

Stirling engines just haven't received the focus of the best and brightest, other than a very select few. My belief it's that's because they can never make a good car engine, despite many attempts. For some reason when people, especially engineers, hear the word "engine" they think it must power a car or it's worthwhile to pursue. Stirlings just aren't sexy enough.

I understand that several of the best stirling engines are being adapted to residential solar dish stirling setups, which should become commercially available over the next year or two, and after trying my hand at it, I'll just wait for something from the experts.

On the other hand, I do believe there is some potential for something that's DIY. My personal preference would be something that functions on a low temperature differential (LTD). Yes it would be very large and heavy and unlike anything typically thought of as an engine, and the only way to make something like that economically sound would be for it to serve a dual purpose. eg having the heat collector also form the roof of a house, so instead of going on top of your roof, it would BE your roof. The idea of a slow, heavy, giant engine wasn't even sexy to the guys in the HAES (Hot Air Engine Society), so I became discouraged, though I keep falling back to those little LTD stirlings that will run just from the heat off of your hand as proof that the concept will work. Durability and low cost are likely to be the stumbling blocks though.

For the DIYer it really is best to start with solar hot water, and solar heating (if you live in a northern climate) or a passive solar strategy for keeping your home cool in a warmer climate. These strategies will pay for themselves in a relatively short time and are easy to do. If you live in a region with decent wind resources, that's a great DIY power project, which actually is solar. Then with your power needs much lower, PV or hopefully soon to come solar dish stirlings will become available, along with cheap electrical storage systems.

I'll call this my 3 cents, since I've done a lot of in depth research in this area.

John
 
Back
Top