PV Gap

Edward Said:

solar powered heating source?

We Answered:

You would need a battery to store the energy gained by the solar panel during the day, and release it at night. You'd also need to make sure the bulb works properly with a DC current (incandescants do)

Another option, if it's Sunny enough, is to make your own solar heater from black tubes filled with water with some mirrors set up around it (tin foil will do if you don't want to spend much). Water has a high heat capacity and will maintain heat for a while.

During the night, move the foil closer around the water tubes/bottles. This will reduce heat escaping out from them, just like insulation.


If you live in a warm area with lots of direct sunlight, then this is worth trying out...

In all honesty, it'll probably be much easier, cheaper & more effective to run a wire out to the back and use mains electricity.

Finally, insulation is important!

Violet Said:

What kind of battery do I use for a solar powered heating device?

We Answered:

What you suggest is not a commonly done thing. By the time you store solar energy in a battery, and get it out again as heat, you may have thrown away 95% of the energy. Also, heating applications take a lot of energy, so if I had (say) a 200-watt panel, I would not expect to do more than warm a cup of coffee for a few minutes with it.

To answer your question about batteries, the standard battery used for storing off-grid electricity is lead-acid, AGM type if you can afford it. If cost efficiency is not important, you can get lithium oxide batteries that are intended for electric bicycle use. A 0.3 kWh battery of that type costs about $500, 10x what a lead acid would cost, but it will be smaller, lighter, and you can drain it flat without harming it. You can find such batteries by Googling "electric bike battery."

If your goal is to store solar heat, it would be cheaper to have a very large collector, heat water, and pump it into a large, well-insulated tank.