Over the last 13 years since we purchased our home in Maine I have been working at reducing our energy footprint as part of my commitment to live as sustainably as practical. My strategy has been to reduce usage by improving things like building insulation and consumption in general. But also I have added renewable energy sources such as a solar heating system for the hot water in our home, and the solar electric system I installed. I decided to review my progress so far since I have extensive data on all of our energy sources and costs. This information is derived mostly from our utility bills.
We use propane to heat the house and also for cooking, clothes drying, and water heating. Below is a chart showing our annualized cost for propane per heating season. Some of the variations such as the spike in 2010/11 are due to fluctuations in the cost of propane, but the trend is largely due to my efforts since the cost per gallon has been increasing.
Not factored into our relatively low propane costs is the fact that we burn approximately 2 cords of firewood per year at a cost
ranging from $300-$500 per year. Last year we spent $425 for firewood which brings our recent total heating cost to a little over $1400 which is less than half the state average for home heating costs.
As you can see our propane consumption dropped about 50% over the years from almost 800 to a little over 400 gallons last season. Part of the reason for our initial lower cost was that our home (constructed in 2001) was reasonably well-built, insulated and relatively tight compared to an average home. Some of the things responsible for this reduction are:
* Improved basement insulation added to exterior concrete walls.
* Tightening up the building envelope by foam insulating air gaps around window and door framing.
* Adding interior storm window panels and closing honeycomb insulating shades in the cold winter nights.
* Weatherstripping around exterior doors and improving attic insulation.
Thanks to the solar power system I installed, our average electric bill would be around $10 if we did not have the Chevy Volt electric vehicle which adds approximately $45 per month to our monthly bill.
One can look at all of the investments I have made in reducing our energy footprint in terms of return on investment. In actual dollars most of these investments have already paid for themselves, such as the solar hot water heating system which according to my calculations paid for itself in approximately 4.5 years: