New York City, with its massive buildings, high population density, poor ratio of roofttop to resident, and rather northerly latitude, has represented a tough frontier for solar energy to conquer. Eight years ago, when I looked into the economics of putting a photovoltaic array on the roof of a home in the central Brooklyn neighborhood where I reside, I found that even with enormous state subsidies, going solar did not pay.
As laid out in a book about energy and climate that I was writing at the time, for a PV array costing about US $32 000, the homeowner stood to collect $20 000 in subsidies from New York State. Still, the payback period would be at least a decade—and then only if everything turned out to work as advertized.
Now, however, a few PV arrays are popping up on roofs in my neighborhood. The ones nearby are being installed by VoltaicSolaire, a four-year-old company founded by Carlos Berger, owner and operator of a successful electrical contracting business. (Why the French-sounding name? He just wanted the company to sound different, Berger explains.) The arrays are provided by an American company in Wisconsin, says Berger, and the PV material is standard silica.
Berger says that VoltaicSolaire's system installation costs run $4 to $6/Watt. The installer stands to collect a 30-percent subsidy from the federal government upon completion of the system, with another 25 percent (up to $5000), coming from the state of New York.
Even so, the economics are still a close call. Berger says the expected payback period is now 5 to 7 years, a big improvement from what it was eight years ago. But the installation will pay off only if the home has a rooftop with a large expanse facing south or southwest. (A killer eight years ago was that my roof faced mainly west.) Another set of hurdles are the bureaucratic type. Obtaining city building permits can involve a lot of red tape, and so can getting net metering set up, which is essential. Berger expects such obstacles to diminish with time, however.
Will we soon see a deluge of photovoltaic installation in places like Brooklyn? It will depend largely on whether global PV prices stabilize near their current level—despite a general meltdown in solar manufacturing—or bounce back to much higher levels. Future price scenarios are explored in a current IEEE Spectrum news report by Peter Fairley.