How do you build a solar panel at home?

Really can't. Solar cells are made from purified silicon and other materials in very expensive factories, because the process involves precision mechanics and special chemicals. Not something you can do at home. The instruction you can find online are actually to construct a solar panel from solar cells. That is like wiring batteries in series and parallel, a lot different from actually making the cells, which is what you seem to be asking for.

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http://www.google.ca/url?sa=t&rct=j&q=home%2Bbuilt%2Bsolar%2Bpanel&source=web&cd=10&ved=0CJ8BEBYwCQ&url=http%3A%2F%2Fwww.instructables.com%2Fid%2FMy-home-made-solar-cell-1%2F&ei=CaeuTtntCcfj0QGjgf22Dw&usg=AFQjCNHh3jfk-lzagheETBSlb84QBxpqbw

You are going to need solar panels mirrors, module, spi sun simulator, spi laminator, spi assembler, spi cell sorter and solar cells. I can say it’s hard to build good effective solar cells, it going to cost you a little bit.

I can't answer for a photovoltaic (electric) collector, but you can certainly build a thermal collector easily. (Not safe for drinking water). Build a 4'x4'x2" box using a half-sheet of plywood and some 1x2 strips. Coil 1/2" plastic or copper tubing and attach it to the plywood (the more loops in the coil, the better). Extend both ends of the coil thru holes drilled in the box. Now spray-paint the whole box black and cover with a sheet of glass or plexiglass. Attach the tubing to a hose running to a tank positioned higher than the collector so that the hose at the top of the tank connects to the tube at the top of the collector. Place the collector in the sun, and you should be able to heat the water in the tank quite easily.

Solar electricity is not cheap because the basic cells are not cheap. Solar heating can be air or water Air is cheaper because you basically built a box with glass on one side and paint it black inside with some baffles to extend the flow path of the air. A fan blows cool air in and hot air out during the day. Rocks or water can be used to hold the heat for night time use. Water (or water plus antifreeze in cold climates) requires tubing of some kind that will conduct heat and withstand the sun. Copper has traditionally been used because it comes in long lengths and can be soldered to a backing sheet to increase collecting area, but copper is costly right now. Again there has to be a box painted black with glass on one side. A large insulated tank can store heated water for night time use.

The most cheapest solar cell small panel can be taken out from solar power calculator. Go to Dollar shop buy one large calculator costs $1. Remove the solar panel,placing it to direct hot sun. Output form both terminal has 1.5V , measure it with voltmeter. Put more these cell panels together in series to obtain higher voltage.

Make Solar Panel At Home : http://www.CreateHomeSolar.com

The most cheapest solar cell small panel can be taken out from solar power calculator. Go to Dollar shop buy one large calculator costs $1. Remove the solar panel,placing it to direct hot sun. Output form both terminal has 1.5V , measure it with voltmeter. Put more these cell panels together in series to obtain higher voltage.