Solar Power for $50 – Seriously, Build It!
You may not believe it, but it’s true. I built it myself a few years ago, and you can still do it today for less than $50. So let me first say that this is a solar hot air generator heater, not an electric one. Construction is very simple, and the average Joe with basic ‘homeowner’ tools can easily put this together. When you stand by a well-insulated window in the dead of winter with the sun shining through it, you can feel the warmth of the sun. Well that’s the beginning and from there you can build your dashboard with that in mind.
The basic materials are:
– 1 sheet of 1″ x 4′ x 8′ Celeotex Thermax TF-610
– 1/2 sheet + 3/4″ x 4′ x 8′ Celotex Thermax TF-610
– 1 tube of Liquid Nails panel adhesive
– 1/2 tube of silicone caulking compound
– 16 Sheetrock Screws
– 1 plexiglass to fit in panel
– 1 all-metal foil tape
– 1 can of high temperature black header paint
– Assorted wood, scrap
You can vary this list depending on your design. I used furring strips to create the frame and Styrofoam instead of Celeotex. I’m always thinking cheap, but useful. One of the limiting factors is the size of your window. If you have a small skinny window, then your pane can’t be much larger than the opening. This was an issue I had at my location, my window opening was only 19″. But I was able to make it 80″ long.
The panel is built with two chambers, one at the top, with the glass and painted metal sheet, and another below that sucks in fresh air from the room. There is a 4-6 inch opening at the bottom of the panel between them for cool air to travel through the heated platen and get hot.
The small panel, only 1520 square inches or 10.5 square feet, was able to heat 3 bedrooms and a bathroom! So despite the small size, it sure was powerful. You may be wondering my location and thinking, sure you were in Florida or Arizona! No, I’m located in the cold, gray northeast, southern New England, a little place known as Rhode Island.
Some construction tips; You must keep the panel away from soil, insects, rodents and moisture. Also calculate your own angle for your latitude. Here’s some help with that. The winter season has less sun, so you want to make the most of it. To calculate the best bank angle in the winter, take your latitude, multiply it by 0.9, and add 29 degrees. The result is the angle from the horizontal at which the panel should be tilted.
The best place to get your latitude is in Google Earth, it appears at the bottom of the window and is followed by N. One modification that made a big difference was the addition of an old squirrel cage fan and thermostatic switch. The fan was free and the switch I bought from an HVAC supply house. The switch was preset to turn on at 120º and turn off at 80º, it was one of those push buttons, non-adjustable sensors. You have to try this, it’s only a few hours and very little money.