Installation complete

Today we installed a 1.61kw solar panel system on our roof in suburban Maryland. It consists of seven SunPower panels on the roof on the left side of our house, facing almost directly south, tilted about 30 degrees, and with almost no interference from overhanging tree branches.

In short, it's an ideal spot for solar panels. The small system should produce 1.9 megawatt hours per year - 15% of our annual consumption, enough to cut our energy bill by $330.

It's been almost exactly three years since I caught the renewable energy bug, in early 2006, when a neighbor explained at a cocktail party that global warming is happening right now, and not over some centuries, as for some reason I still believed was the case. Within weeks of that conversation, after hours of Google-led self-discovery, I had replaced more than 30 lightbulbs in our 2,500-square-foot house, become a fanatic un-plugger, and set up an Excel file tracking our monthly kilowatt consumption back to 2004.

Also some time in 2006, I computed the cost and returns of investing in solar panels, and decided that the technology, the incentives, and my household finances were not quite ready. By my calculations at that time, a 2kw system would cost about $20,000, minus government incentives of maybe $4,000, resulting in an internal rate of return of less than 2%.

Three years later, while the technology and the household finances are not particularly different, the government incentives are dramatically better. The system will cost $15,990, but with Federal and County tax incentives and a State grant, we are hoping to pay less than $4,500. The annual savings will be about $330 on our electric bill, but due to another government program, we hope to earn an additional $700 or so in the first year by selling renewable energy credits, declining each year.

In all, the system should pay back its cost in six years.

I'd like to use this blog to document my family's solar adventure, hopefully making more transparent a simple technology that still seems exotic to most of us. I'll put up photos, regularly track our production against expectations, and let you know exactly when the government incentives pay off - and whether they pay off as expected. I'll try to note any technical hitches as well as any hidden costs that may come up. For example, I had to upgrade my electrical panel because the existing panel had no main disconnect, adding $1,500 to the bill. (Does replacing the 17-year-old shingles on the roof count as a hidden cost or something we would have done anyway? You decide.)

I'll also talk about our efforts to reduce our energy consumption, which of course is the cheapest and best way to reduce your carbon footprint. After the initial assault on consumption, I'm not glad to report that those kilowatt hours have been creeping back up.