Building out solar installations at affordable housing complexes isn't easy. Like with residential solar projects, installers often have to worry about shading from trees and pitched roofs. The projects also aren't as big as some of the mega-solar projects being proposed by utilities.

But the subsidies are nice. The state of California pays $3.30 a watt for solar panels to power common areas – i.e., parking lots and hallways – and $4.00 a watt for solar panels to provide power to individual apartments, says Richard Raeke, director of project finance at Borrego Solar.

The subsidies can be determined by square footage if the complex is on a centralized master power meter. If 20 percent of a complex's electrical load gets consumed by the common areas, 20 percent of the rebate is at the $3.30 rate and the rest goes at $4.00. 

"We're really looking at 40 to 60 percent of the cost," he said.

By contrast, standard homeowners get $1.55 a watt in California.

In the past few years, Borrego, one of the state's older solar installers, has made affordable housing complexes one of its specialties. (Borrego currently receives about 75 percent of its revenue from commercial projects.) The company has installed 3 megawatts of solar at affordable housing complexes and expects to install another 2 megawatts this year.

Overall, affordable complexes in California could accommodate about 30 megawatts of solar, he said.

The state has also created a solar subsidy for low-income individual homes that range from $7 to $5.75. At $7 a watt, the subsidy would cover more than the cost of installing a solar system now, which can be put in for just under $7 a watt. Nonetheless, the building must be occupied by residents with federal income tax liability ranging from $2,000 to zero.

California set aside $108 million for the Multifamily Affordable Solar Housing (MASH) program as part of its comprehensive solar initiative. The state's public utility commission fleshed out the program in November 2007. However, it only began accepting applications somewhat recently. The money will be spent over the next four years.

Affordable housing complexes can also qualify for the federal investment tax credit. If the complex is owned by a for-profit company, it qualifies. If it is a non-profit, the non-profit can create its own renewable power provider, which will own the panels and sell the power to the mother housing complex. 

Join industry leaders and influencers at Surviving the Shakeout: Greentech Media’s 2009 Solar Industry Summit in Phoenix, Ariz., April 14–15.