self sufficient life

Heat and power, power and heat

In Europe, Canada and the US, the power companies are required to buy back any excess energy you create. The rates, at which they buy back the energy, depends on a few things and the rules are different in each country and state. You can get detailed information on this subject from your utility company.

Solar energy, for instance, will be paid at a higher rate than power generated with a diesel generator because it is obviously much cleaner energy. In Europe you will also get a better rate if you burn vegetable oil instead of diesel, but you will have to show proof of the origin of your oil, so waste vegetable oil collected from restaurants will not get you the higher rate, although the collected oil will be cheaper than buying new vegetable oil, possibly still making it an interesting alternative on the bottom line.

The amount of energy you can sell back also differs from each power company to the next. While some will buy back as much as you can generate, others will only buy back as much power as you buy from them, effectively leaving your power meter at the zero mark.

Since we are currently looking for a new house, I don’t know which power company we will be dealing with. Assuming, for now, that I can only sell back the amount of electricity that I use, generating our own power will not bring in any money. After working out the fuel usage for the generator and assuming that I have to buy vegetable oil to run the generator, plus the generators initial purchase price and ongoing maintenance, the bottom line is that the power from the utility company will cost about the same or maybe even a little less.

However, the electricity is not the only thing I will be generating. A big part of the energy will be lost as heat. Lost if you don’t catch it, that is! Running the engines cooling water through a heat exchanger in the central heating system will have a positive effect on the total fuel consumption of the central heating.

The whole thing can also be turned around: so, instead of running an engine to cover your power needs and use the excess heat to complement your central heating system, you could also have the engine running to generate the heat to warm your water and house, while running a generator head along side to create electricity while you are heating. Sure, ultimately we are talking about the same system, that generates heat and power, but the sizing of each system would be different.

How our system will be sizes isn’t decided yet. We will first have to find a suitable house. Depending on the age and condition of the central heating system, we will then go one way or the other.