Hi all,
Though most of us here are tinkerers at heart, I thought it would also be helpful to post a bit of info I've collected about my efforts over the past 2 years to cut down on my energy consumption.
Step 1: Install a programmable thermostat (cost 50$, saved 500$/year):
This has been the most successful change. I have measured a 50% reduction in annual energy consumption due to this device. My 1800 sq.ft. house is heated with natural gas by a 57,000 BTU furnace. The insulation coefficient of the walls & floor are approximately R20, the roof is R34. I am now using 76 GJ (gigaJoules) of natural gas per year to heat the house. Previous occupants of the house consumed over 150 per year. I've programmed the thermostat to turn the heat down to 16C during working hours, when I'm not home, and overnight, when I don't care. Living near Calgary, Canada, I don't need the furnace only between May and September. Winter temperatures are often mild, but every winter has many spells of -20C or below, which consume the lion's share of energy.
Step 2: Install compact fluorescent light bulbs (cost 40$, saved 0$):
This has been a bit disappointing. Summer electricity consumption is hardly affected by light bulbs - the sun goes down at 10PM in June. Winter's additional electricity consumption is dominated by electric heating of animal water troughs (to prevent freezing), and running the furnace blower motor. Lights are on more often, but the CFL's just trim the margins.
Step 3: Buy a compact car (cost 4000$ used VW Golf, save 400$/year):
Mixed results, here. I can't drive the mini car in the winter. Even with snow tires, it's too light. During summer months it consumes 25% less fuel, but is less reliable than my sedan. The engine in my sedan, BTW, produces more than 2X more power, using just 25% more fuel. The efficiency is surprising. Both vehicles show a 10% decrease in efficiency during the winter, due to various combinations of winter tire resistance, slippage on snowy surfaces, auxiliary loads (lights, heat), and perhaps off-peak sensor settings (the sensors and computers are tuned to maximize fuel economy in California, after all).
Conclusion:
After doing a bit more math, I estimate that I am putting 25% less CO2 into the atmosphere due to my efforts. Future attempts to cut down on my electricity consumption (the water heating is a killer) would make the greatest impact.
Blame:
Split 50%-50% between climate and lifestyle choice. I'm not sure what would be easier: make Alberta 10 degrees warmer, or make me move back to the city.
Steven