Since the nearest utility lines are over a mile from our property, and that they're not too reliable in bad weather, we know that we'll need to generated our power on site at our cabin through some combination of Solar PV, Wind Turbine and combustion generator. When it comes to purchasing home energy systems, a watt saved is a dollar earned, so we decided to go on an "energy diet" while we were still on the grid in order to more properly size our system.
We were already a bit more conservative in our energy usage than the reported average household, 7 kwh a day vs. 30 kwh a day. But, we wanted to see exactly how far we could trim this down. Could we get it under 3 kwh a day which is easily within the production capacity of an affordable-priced system? And we weren't just going to look at kwh of electricity, we decided to also take into account our natural gas and water usage... both of which were also already below national average.
First, let me tell you... when you live in a house on the grid, especially in a city, there are more things that you can't do to conserve energy than you'd think. For instance, our house has central forced air heating with gas furnaces, high-efficiency gas fireplaces, gas water heaters, and a gas cooking range. These appliances are all much more efficient than their electrical counterparts because making heat with electricity is a very "lossy" application. You burn something, use the heat to make electricity, transport it through wiring from the plant to the consumer (losing power due to resistance), then put it through more resistance to make heat... see very inefficient! BUT - natural gas is a fossil fuel and the prices skyrocketed this year. However, much as we would have liked to used wood for all our heat-generating applications, that was not an option in our city house... regulations, lack of forests, smog-control "no burn days". We also couldn't make the most of solar (PV or thermal) because of the location and siting of our home. And forget about a wind turbine, that would never make it past the building permits!
Anyway... we already had all the usual efficiency measures like low-flow faucets, Energy-Star appliances, programmable thermostats, and low-watt lighting and that had already gotten us below the national average on all counts. We also stopped using as many appliances that had phantom loads as possible, and lowered the thermostat on the furnace even farther then curtained off the living room so we could use the fireplace to keep the main area more comfortable with less wasted heat and energy. We hooked up all our rechargeable "gadgets" to a power strip with a timer so that we were only using electricity to recharge the battery (about an hour for most things) rather than continually running (and losing!) electricity in all the transformers.... the timer does generate a small phantom load, so we're looking for one with a manual timer rather than a digital one. We also started making judicial use of blinds and curtains to control light and heat. We were lucky to already have large skylights in the front of the house, but we did consider putting in a solar tube in the back hallway for even more daylighting. We put a timer in the bathroom to control how much time we spend in the shower (they also make shower head timers!).
Well, we have managed to get our electricity down to just under 5 kwh a day, and lower our gas and water consumption another 20%. When we switch to wood heat and are able/allowed to dry our clothes on a line, we should easily be able to get under 3 kwh a day and not rely on natural gas (or only small amounts of propane at least). Yippee! Surprisingly, we really aren't sacrificing any of the modern amenities and conveniences either... just using them a little differently and paying attention more. But we are very happy to know that even a small, relatively "inefficient" renewable energy system will adequately meet our power needs at the bush cabin.