Editor's Note: Scientific American's George Musser will be chronicling his experiences installing solar panels in Solar at Home (formerly 60-Second Solar). Read his introduction here and see all posts here.
It’s the eternal question: Buy now or wait? Assuming you want to install solar panels on your roof, should you go for it or hold off for better technology or lower prices? I don't have a definitive answer, but let me offer a few thoughts that might inform your decision.
Obviously, solar installers want you to jump in forthwith. Even leaving aside their self-interest, they do make some good points. There's really no need to wait for technology to improve. In terms of how fast they become obsolete, solar arrays are more like cars than computers. Although photovoltaic cells and auxiliary equipment such as inverters are getting better, progress is slow.
For computers, technological improvements make the difference between Pong and Left 4 Dead. But as long as a solar panel produces a kilowatt of power, it doesn’t really matter how swanky it is. Arrays of the future will produce more power, but existing ones are not about to become an embarrassment. And it's not as though technological progress will pass you by. Few arrays take up every last inch of roof space, largely because of the limitations of current inverters. You'll be able to add more advanced panels with built-in inverters to fill in the gaps.
A more important issue is cost. Solar panels have gotten cheaper over the past couple of years, not because of technological breakthroughs but because of mundane factors such as increased manufacturing capacity in China. Installation, too, is coming down in price as contractors get the hang of it.
These trends hasten the day when solar will achieve parity with fossil fuels, but have less impact on a homeowner's bottom line, because states are scaling back their subsidies at the same time. New Jersey, for example, is set to reduce its cash grant from $1.75 per watt to $1.55 per watt.
I think the best argument for holding off is that contractors, inspectors, and regulators are still climbing up the learning curve. Right now, you need a good deal of patience and fortitude to install solar panels. The way around this is a power-purchase agreement or leasing arrangement from a company such as SunRun or SolarCity, if they offer one if your area. In addition, large installers such as Acro Energy are working to speed up the installation process.
Another argument for delay is that conservation measures such as insulation or adjustments to your heating system might give you more buck for the buck. A fellow solar blogger, Osha Gray Davidson in Phoenix, Ariz., told me how he reached this conclusion:
We decided to take your advice and concentrate on negawatts (conservation) first. We're getting bids to replace our aging roof with an energy-efficient one and coordinate it with installing solar panels. 1BOG just entered the Phoenix market and they're preparing a bid for our house. We also cut back on air-conditioning this summer by installing an energy-efficient single-room ductless air conditioner by Fujitsu. Mounted on my home office wall and with the compressor outside, I keep my office comfortable and quiet during the day without cooling the entire (empty) house with central air. Our power usage was 11% less in July '09 compared to July '08 (July being the month with the highest power usage).
We've cut way back on driving as well, partly thanks to the coming of light rail to our city. We use it all the time and love it. And my wife bikes to work now that the day-time temperature has dropped below 100. We still don't have solar panels on the roof, and I'm looking forward to that day. The larger work to reduce our carbon footprint is going well -- and continues.
I highly recommend getting a home-energy audit and studying the auditor's cost-benefit analysis of specific steps you could take. Some things that seem like good ideas, such as installing new windows, have surprisingly long payback periods, and solar panels are actually a better use of your money.
Solar panels on George’s roof, courtesy of his brother Bret Musser