When you subtract out shady roofs, renters, and other factors, only about 25% of Americans have a place to install solar power. With the high upfront cost of a complete system, the potential solar universe shrinks further.
That changes with “community solar.”
After a long wait on the state’s Public Utilities Commission to finalize the rules, Colorado’s “community solar gardens” program (my summary here) sold out in 30 minutes when it opened two months ago, testament to the pent-up demand for solar among who don’t own a sunny roof. The program allows individuals to subscribe or buy shares in a local solar project, and in return receive a share of the electricity output.
The community solar garden policy offers several significant benefits:
- Individuals can go solar without a sunny roof or without owning one at all.
- Individuals can buy as little as a 1 kW share or as much as produces 120% of their own consumption.
- The solar garden projects capture economies of scale by building more panels at a single, central location and capture the advantages of decentralization by interconnecting to the distribution (low voltage) part of the electricity grid close to demand.
- Solar gardens cultivate a sense of ownership and geographic connection, requiring subscribers to live in the same county as their shared solar array. This can reduce political opposition to solar projects and increase local economic benefits.
Fortunately, Colorado isn’t the only state considering this policy. California’s legislature is recently debated SB 843 to allow “virtual net metering”, a blanket policy that lets customers share the output from a single renewable energy facility, although sometimes it’s limited to certain types of customers (municipalities, residential, etc.).
Other Resources on Community Solar:
- ILSR’s 2010 report (including a discussion of solar gardens): Community Solar Power: Obstacles and Opportunities
- The Solar Gardens Institute, a nonprofit dedicated to seeding the concept in Colorado and beyond
- NREL’s comprehensive Guide to Community Solar
