I’ve long toyed with the idea of getting solar panels. My house in Boulder, Col., is perfectly situated: It has a south-facing asphalt shingle roof, including the roof over the four-car garage, and being a relatively new house, it has few trees to block the sun. Boulder, located just east of the continental divide and about 50 kilometers from Denver, gets an amazing amount of sun: an average of 157 sunny days and 184 partly sunny days each year, according to the Colorado Climate Center.
But whenever I tried to crunch the numbers—the cost of the equipment, the cost of installation and maintenance, the eventual payback, rebates, and so on—solar never seemed financially viable. In part that’s because electricity rates in Colorado are dirt cheap. Until just recently, rates were a flat US $0.12 per kilowatt-hour. In California, by contrast, tiered rates start at 11.9 cents/kWh and can climb as high as 49.8 cents/kWh. I figured solar would at most save me about $1000 per year in electricity, so how could I justify installing a $40 000 system?
Then one day a few summers ago, I was eating at Beau Jo’s, a pizza place in Idaho Springs, Col. All the Beau Jo’s restaurants switched to solar and other renewables a while back. [For more on the restaurants’ green initiatives, see Beau Jo's Web site.] I spotted a big rotating LCD screen that showed the following:
- Kilowatts being produced now
- Kilowatts produced today
- Cumulative kilowatt-hours produced
- Cumulative tons of CO2 saved
Tons of CO2 saved? Of course! The financial picture was important, but there was the bigger picture to be considered: the impact on the planet. This aspect of solar hadn’t really been in the forefront of my thoughts, but now it made sense. Switching to solar wasn’t just about dollars and cents.
Step 1: Research
I’m an engineer, and so for me the first step in going solar was research. I started with my home’s electricity usage. The house, built in 2000, has 3500 square feet of finished space (about 325 square meters), and my family’s average annual electricity usage is about 8000 to 8500 kWh. Of that, our central air conditioning is a big contributor. Our wonderful view of the Rocky Mountains is provided by large windows on the south and west sides of the house. The downside to all those windows is that the solar gain indoors is truly impressive during the summer, when daytime temperatures can easily rise above 32° C, necessitating the cooling.
Next I looked at the rebates that my electric utility, Xcel Energy, was offering customers who switched to solar. At the time, the rebates were pretty generous. During the summer of 2008, the utility was paying $4.50 per watt for panels installed. Given that the price of a panel was around $4.50/W, Xcel would basically be paying for the panels while the homeowner paid for the installation. Based on what I’d been hearing, though, it was clear that this generosity wasn’t going to last forever. Also working in my favor was a federal government tax credit that would let me write off 30 percent of the system’s price tag after other state and local rebates had been subtracted, up to a cap of $2000. Suddenly the price of solar was looking very reasonable.