31 March 2009—John F. Kennedy once famously described Washington, D.C., as having all the charm of a northern industrial city and all the efficiency of a southern town. When it comes to solar energy, something of the same might be said of the adjoining mid-Atlantic states: They have winter days that are almost as short as New England’s and summer days that can be as humid as South Carolina’s. Yet this past winter, nestled in a Delaware River landfill that’s somewhat of a mecca of renewable energy, the largest photovoltaic (PV) plant east of Arizona came into operation. It’s doing a nice job of delivering electrons into the Pennsylvania–New Jersey–Maryland grid (the PJM Interconnection), but at a cost that’s a little hard to make sense of.
A PV plant like this one, which was built in Pennsylvania’s Bucks County, subjects solar electricity to its toughest economic test. Photovoltaic electricity comes closest to paying for itself when it’s used in distributed situations—without connection to the grid—such as on the roofs of houses or office buildings. That way, it competes against the costs incurred by fossil-fuel and nuclear plants to both generate electricity and get it to the user. But when PVs are used to generate electricity centrally, achieving competitiveness is much more challenging. PV plants that link to the grid compete only on the cost of generation itself, because they incur the same transmission and distribution costs as generators running on fossil fuel and other nonrenewables.
The Bucks County plant, which consists basically of polysilicon modules assembled into arrays of panels, has the capacity to produce 3 megawatts—enough to power about 3000 homes. The modules were manufactured by the Chinese company Suntech, and the plant was built by the U.S. subsidiary of the German renewables integrator Conergy.
Beyond that, the plant’s family tree gets complicated. Shortly after building the plant, Conergy sold it to a bank, which in turn flipped it to another bank, but Conergy continues to operate the plant under contract with the second bank. That bank also has a 20-year electricity sales contract with Exelon Corp., owner of the local electricity distribution company, PECO. Exelon sells the electricity into the regional grid managed by PJM, the system operator, and, through PJM, markets the renewable energy credits (RECs) that it collects for supplying the solar electricity.
When we visited recently on a warm winter day, the plant was a surprisingly beautiful sight. It’s nestled in what’s called a retention basin—a water runoff area required in almost any new development—surrounded by rolling hills formed from municipal waste. Little pipes topping wells, part of a methane capture system, pop up like mushrooms from the hills, and thousands of migrating birds alight on them, attracted evidently by the smell of refuse. With the Delaware River in the background, it must be one of the world’s loveliest garbage dumps.