Solar Garage Heat?

I am wondering about the possibility of creating a DC heater in my garage that runs off of a battery recharged by solar power. The idea I have is not that it will get blistering hot but be heating the garage enough to bring the ambient temp up say five to ten degrees. As most houses with garages these days, there is a bed room over the garage and two walls of the garage are shared with living space. Needless to say, the insulation is not sufficient. So my thought is if the sun can power a heater that will help heat the garage, the house will also benefit.

In reading about similar ideas, there seems to be a voltage regulator between the solar panels and the battery. As I know oh so little about such things, can anyone point in the correct direction possibly to articles on line to assist?

Just off the top of my head: No. The cost of setting up a solar kit for electrical resistance heating isn't economical. You'd be better off putting all that money in an account, and using the interest to pay for electricity to run a space heater. For instance, you can get a 100W panel for $100. So, in full, mid-day sun you'll get 100 watts (for a few hours). Mostly you'll generate some percentage of that, and it may not be a large fraction. A typical hair dryer is 1500 watts, which may, or may not do the job. So you can do that math. And we haven't even thought about the installation costs, or batteries - the cost of which will kill the project, if it's not already dead. Generally, you want at least 2x as many Ah in battery capacity, as you need.

The way to do it would be a passive system (water running through some kind of black solar heat collector). You can easily buy passive solar water heaters at a pool/spa store, put a couple panels on the roof, and plumb those into a variety of things in the garage (a heat exchanger, anyway). Add a photovoltaic panel and a small pump to cycle the water. The only question is how big does it all need to be?

But you could get started, and it might be interesting to see what you need. Put a space heater out there. Run it for various amounts of time (with a timer, not the thermostat), and add up how many kwh you need to get where you want to be, as well as the indoor and outdoor temperatures you're dealing with. Then you'll have to figure out how much heat you're liable to collect from books and maps on the topic. If you're heating in the winter, you're probably sunk (I'm not really familiar with NC winters).

Solar pool heaters work because people run their pools in the summer, when there's lots of energy to be had. Off-grid homes normally have some other source for heating, like a wood stove. Also, refrigerators for off grid living commonly run on propane, because they're power hungry appliances as well.

Hope that helps. It's an interesting topic, for sure, and there are lots of books out there. Regardless of what you do, the biggest bang for your buck would be to insulate the garage. :-)

If you have a good southern exposure you can go passive and create an external collector that can add warm air during the day. That plus insulation may be enough in NC