The fine folks at Namaste Solar just finished installing a 3.01 kW grid-tied PV system consisting of fourteen SunPower panels on the roof of our garage behind our new house in Boulder, CO. Now I have to wait a couple weeks for inspections and for Xcel Energy to tie it in to the grid and install the net-meter, at which point this system will be generating enough clean, zero-emissions electricity to cover a significant portion of our home’s energy needs. I would have loved to have completely cancelled out our electric bill, but we used all the south-facing roof space we had available to us, and ran out of room for additional panels.
Fortunately, Namaste was able to get their hands on the highly efficient SunPower SPR-215 panels, so we were able to maximize the wattage per square foot on our limited roof space. And thanks to Boulder’s 300 days of sunshine per year, we’ll be getting good bang for our buck on this system, which should pay for itself in about ten years, or substantially sooner if energy prices rise more than 5% annually, which I think is a pretty safe bet. And to think that all this power used to just heat up the roof and interior of our garage. Now it can keep my beer cold. Pretty cool.
For the stat-obsessed, here are the basics on the system:
- Electricity production: 4268 kWh/year
- CO2 emissions reduced: 8741 lbs/year
- Equivalent reduction in vehicle miles driven: 9561 miles/year
- Equivalent number of trees planted: 336
If you’ve got the sunshine, roof space, money and inclination, why not install one on your house? There’s a $2000 Federal Tax credit available, and several states now offer substantial rebates (Colorado included) that can cut the cost of the system by up to 50%. Before I decided to move to Colorado, I was investigating putting one up on my house in California, where the payback was even quicker (about seven years) due to the higher energy prices. As energy costs rise and as new technologies become available that make PV cheaper and more efficient, the payback window will ultimately shrink to the point where it would be a bad idea to not install a PV system.