Space Heating

Probably one of the greatest challenges of any home owner using RE is heating. There are certainly pros and cons of almost any system. Let's look at what doesn't work. It's pretty impractical to use PV panels for space heating, not only would the size/cost of the array be prohibitive, but the battery bank would need to be immense. The same goes for wind electrical power, while it would be somewhat more attractive to put up, say a 5 kW wind mill and use it for heating. It would only provide the required power during high winds, or the storage issue again would make the system unattractive.

Next what could work. Pellet burning stoves would seem to be viable, although they require in most cases about 3 kW of power daily to run. So a pellet stove could be an option, but it would require a significant expenditure in extra solar panels and battery storage. A conventional forced air furnace, or hot water heating system using LPG or natural gas could certainly work. The downside of course is the electrical power to run these systems and the fact that you're using a non-renewable source of energy. A hot air solar system with rock storage can meet most if not all heating needs. The down side is the expense and huge pile of rocks that are required to store adequate amounts of heat. The same goes for solar hot water collection systems, in theory it could provide most if not all a homes heating needs, but a system sized large enough in cold winter areas would be large and very expensive.

A system that is time tested and proven to provide all a homes heating needs is of course a good old fashioned wood stove. Modern wood stoves are efficient and clean burning, I'm not going to buy into the wood stoves as a huge source of air pollution any more. With a high efficiency wood stove it has almost a neutral carbon impact, the CO2 and pollutants a tree absorbs during its growth are pretty close the pollution level it creates when the wood is burned. It's also a renewable, trees grow where a tree is removed. A good option, but down sides too. You need a supply of wood in your area, a way to cut it and split it, then a place to store it. Of course it's also a lot of work (been there done that).

A nice stop gap heating method for a RE home is the ventless gas heaters. It's what I've been using for 15 years. They are very efficient, low polluting and require no electricity at all. They are also very effective as supplemental heat sources, using the gas heat only when another RE system is under producing. Of course the down side is that you are still using a non-renewable energy source.

I'm starting a new set of solar hot air collection panels to supplement my propane heater. A number of years ago I made a large hot air collector for home heating. I have corrugated steel siding on my building (that I turned into my house), so I simply framed up a 10' x 10' area of the south wall, caulked it, painted it flat black, installed some air baffles and glazed it in a heavy clear vinyl sheeting. It worked quite well, heat coming out of the 6" vent was 120 to 130 degrees and it pretty much heated my house when the sun was shining. But the vinyl only lasted about a year and a half, I tried replacing it with heavy poly plastic, but of course it didn't last long either. So now I'm set to make a new solar hot air collector, the key is that I have four 75" x 33" glass patio doors to use as glazing. I'll start a construction page on the system soon and link it here.