Periodic Grist contributor Gregory Dicum has an article in today’s New York Times that does a great job of telling the story behind solar’s explosive momentum. With state incentive programs closing the cost gap, homeowners make the investment for a variety of motivations. The article manages to work in quotes citing reasons that range from foreign policy …

Mr. Felton, 67, said that a solar system did not make sense when he built his house in 2000, but that the rebate, as well as rising electricity prices, persuaded him to install the system last year. His pragmatic concerns were also informed by broader issues. “I’m not a hippie greenie,” he said, pointing out that with a background in nuclear engineering, he strongly supports nuclear power. “But solar is certainly a way to get off foreign oil.”

As a member of the military who has been deployed to the Persian Gulf three times, Dr. Leininger has been affected by the nation’s foreign oil habits more than most. “The need for stable oil supplies is the big reason that we spend so much time in the Persian Gulf,” he said. “Decreasing our national energy consumption is in my self-interest.”

… to environmental concerns …

Dr. Leininger estimated that his system had reduced his household carbon emissions by nearly 30 tons since it was installed in June, and that it was well on its way to zeroing out.

“It comes down to personal responsibility,” he said. “If I can go electricity-neutral on my house, that’s that much less coal we have to burn.”

… to Benjamins …

And much less money. “One of the most gratifying things is on a sunny day when the meter is spinning backward,” Dr. Leininger said. “We have a guaranteed return on the system because we know we’re not going to have an electric bill from now on.”

Wonks will also appreciate how the article gets the policy factors right. Almost parenthetically, the article explains the importance of long-term incentives:

The theory was that supplanting the year-to-year incentive programs in place since 1998 with the long-term certainty offered by the initiative’s 10-year, $3.2 billion program of rebates (one-third of which would likely go to homeowners) would stimulate the development of a robust solar sector — which could then be weaned from subsidies as its growing scale brought down prices.

And a great description of net metering:

As recently as 10 years ago it was unheard of and, in fact, illegal for solar-powered houses in California to connect to the grid; now power companies are legally required to credit their customers for the excess power they produce.

The grid, in effect, serves to store power, replacing the bank of batteries that is a component of off-grid systems. At the end of the year, credits for solar power added to the grid are applied against charges for power taken from it, helping homeowners “zero out” their electricity bills. According to Borrego Solar Systems, the company that installed the long rows of solar panels on a hill next to Mr. Felton’s house, two-thirds of its customers manage to do so.

Also note mention of the role of utility rate design:

In California residential electricity rates are tiered, and large users like Mr. Felton pay rates about three times higher than more modest consumers, making solar power even more attractive.

While California structures its rates to incentivize lower consumption by charging profligate consumers more, many other states have inverted tier pricing, where customers pay less the more they consume.