Editor's Note: A few years ago, I explored heating my home with solar, but the contractor said I would produce too much heat for just my home, so he would have to find some place to "dump" the excess. I said, "wouldn't it be great if I could share it with my neighbors?" He laughed, but now the idea is gaining ground!
By Dana Hall, James Rose & Laurel Varnado
Have you ever been tempted by a vacation time-share? It's cheaper than buying a vacation home, you get the benefit of relaxation just when you want it, and you don't have to worry about maintenance or keeping up with the bills. Now imagine if you neighbor came to you with a great deal on a solar energy "time-share." Just the right amount of electricity from solar panels would power your lights and appliances, but you don't have to worry about installing the panels on your own roof or the upfront capital to pay for it.
Solar developers will tell you this idea would be quite popular with their customers. Developers frequently turn people away who want to invest in solar but can't because of tree shade, roof condition, building configuration or because they live in multifamily buildings. Other times, developers have to walk away because the building doesn't have enough demand to absorb the generation output and net-metering laws cap the size of projects to serve the load onsite.
That may be about to change with the emergence of community solar ownership. Communities nationwide are developing novel approaches that allow customers to share renewable energy systems, providing opportunities for previously untapped markets.
With traditional net metering configurations, a small grid-tied PV system (under 2 MW) is built for a single customer with a single meter, and the generating customer receives credit for any excess generation at retail rates. The utility distributes the excess electrons to other nearby loads as an ordinary electricity sale. Community solar pushes traditional boundaries by allowing the excess generation to instead offset the loads of an identified group of participating customers who invest in the cost of the system.
Community solar successes to date have been systems managed by the local municipal utility. But some large utilities, state policymakers and entrepreneurs are developing strategies to enable broader adoption of community solar.
Municipal Utilities Take the Lead
Ellensburg's Solar Community Project. In Ellensburg, Washington, three solar systems are installed on city-owned property along Interstate 90. The system became operational in November 2006 with a 36 kW installation. In February 2009, they added 21 kW more and Dept. of Energy (DOE) funding helped them install an additional 13 kW. Another 41 kW will be installed this spring and the city hopes to add concentrating solar this year.
The city owns the land and generation equipment through its Dept of Energy Services - members of the community contribute capital in exchange for a share, or right to the value of the power generated, proportional to their contributions. Customer contributions fund the PV hardware, and the city funds the interconnection, operation and maintenance.
Ellensburg contributors receive a "solar credit" in dollars on their electric bill for the power produced by the system, valued at the Bonneville Power Administration's (BPA) wholesale rate. If someone provides 3% of the project funding, he receives a credit for 3% of the kilowatt-hours (kWh) output factored by BPA's current rate. The total kWhs credited to any individual contributor are capped - s/he can't receive a credit in excess of her annual total electricity consumption.
