Whenever a dinner party has an awkward pause and could use a horror story to liven it up, I tell my story of shopping for solar panels. My wife and I started in 2008 and spent months finding an installer. Some never returned phone calls. Estimates ranged over a factor of two. It was hard to tell which was worse: their knowledge of physics or of finance. Call me a stickler, but think that anyone asking for $40,000 of your money should know the difference between a kilowatt and a kilowatt-hour. We also kept hearing about how our home equity would increase—highly questionable, from what I've seen of how buyers and appraisers value a house.

In the end, we went with 1st Light Energy, the only company whose sales rep could quote inverter specs from memory and spent hours with us at our dining table going over the numbers. Unfortunately, he knew rather less about organizing work crews and screwed up the installation. It took his replacement months to put things right. In retrospect, we dream of how nice it would have been to have customer ratings and unheroic financial analyses.

Finally, someone has developed a website to provide just that. Launched last month, EnergySage aspires to be the Expedia of solar and eventually of other green technologies such as solar thermal and ground-source heat pumps. A similar service, Solar Choice, operates in Australia, but I believe this is the first in the U.S.

On the site, you set up a profile with your address and either type in your electric bill or upload the PDF. EnergySage automatically emails installers in your area to work up an estimate; a homeowner might expect three or so responses within a few weeks. They come to you—no phone tag required. The service is free to customers; installers pay a commission if they get the job. The site presents the quotes in a standardized format, looks up the government subsidies available in your area, and calculates the payback period rather than accept the installers’ analyses.

Already have an array? Then enter it in the site as a case study for others to learn from. I added mine and was gratified to learn that it has an investment return of 17.8%. You can also rate and review installers and equipment suppliers. EnergySage's CEO, Vikram Aggarwal, says the company plans to add other features such as bank loans, discussion forums, independent equipment tests, automatic retrieval of electric bills directly from utilities, and estimates of prevailing market prices—doing for renewable energy what the Blue Book does for used cars.

Not only is this great for homeowners, it hastens the day when solar power will reach parity with fossil fuels. The panels have been getting cheaper and streamlined installation systems are cutting labor costs, so the sales and marketing costs loom ever larger. They now account for a tenth of the total, on average—10 times more than in Germany. By providing a central clearinghouse for referrals, EnergySage should help to reduce these soft costs and fire up installers' competitive spirits. A little less drama in the purchase of a solar array would mean fewer stories to regale your friends with, but more photons knocking electrons into our power grid.

Screen shot courtesy of EnergySage