My friend Reggie recently asked me for advice about installing photovoltaic (PV) panels on the roof of his boathouse on the river. It has no electricity now, but he wants just enough PV to power a...
The future looks bright for distributed PV.
ways to implement it throughout the company’s service territory.
“Building these facilities is a lot simpler than building a large solar farm, in terms of the siting issues and transmission lines,” he says. “We’ll study this project to see how these sites integrate into the grid. It will provide a laboratory to analyze ways to expand as we see fit. There’s no question, it will be a growing part of the mix going forward.”
Six Gig by 2015
Duke’s project is a start, but it’s tiny compared to what’s slated in California.
The California Solar Initiative (CSI), announced by Governor Schwarzenegger in 2004, mandates a million solar roofs in the state by 2018 with a total capacity of 3 GW. The CSI aims to make the state a world leader in solar generation, and it’s ahead of schedule. Some 50,000 customers already are engaged in solar net metering, generating 500 MW of power. The program is directed toward consumers, but has sparked surprising interest in other quarters.
“We didn’t expect to have all three utilities propose to own their own solar distributed generation,” says SunPower’s Blunden.
In addition to the 3 GW of net metered solar, the California Public Utilities Commission (CPUC) has approved 1 GW of central-station solar farms and 2 GW of utility-owned distributed PV.
“A couple of years ago we had just a couple of megawatts installed,” Blunden says. “California now has an incremental 6-GW commitment by about 2015. The great thing about solar is that it’s really fast to market. We as an industry put 3 GW into Spain in 18 months. So if you want lots of solar fast, you can do it with PV.”
One of the major utilities targeting distributed PV is Southern California Edison. In March 2008, the company proposed installing 2 square miles of advanced PV panels on about 150 large commercial roofs. In June, the CPUC not only approved the project, it doubled it.
“In five years we’ll have four square miles of panels on about 300 roofs, generating 500 MW,” says SCE spokesman Gil Alexander. The first already is operating in Fontana, east of Los Angeles. “We went ahead and started even before we got regulatory approval. It has 33,700 panels, 2 MW of generating capacity. The day we plugged it into the grid last fall, it became the largest single solar PV installation in California.”
Additional installations will prioritize load-growth areas, such as Fontana and Chino in California’s burgeoning Inland Empire region. The other main criterion for site selection is the similarity of roofs. Like Duke Energy, SCE will lease from customers, but the utility is relying on uniformity to keep engineering and installation costs down.
Ideal sites won’t have a lot of power demand of their own. “Otherwise, the owner might be thinking, ‘Boy if I just had my own panels on my roof, I could cut down this big electric bill,’” Alexander says. “We offer a monthly check to lease their roof. It’s added revenue for them, and it’s valuable, unused southern California real estate that we can