How Solar-Friendly City Permitting Processes Can Work in the US

A new study from the Lawrence Berkeley National Laboratory (LBNL) puts some hard numbers to the benefits realized when U.S. cities streamline their solar PV permitting processes.

Germany’s residential solar adoption is attributed to friendly policies and incentives, but also friendly permitting processes. Meanwhile, in the U.S., “soft” costs amount for more than half of the installed price for residential solar PV systems in the US. Various studies have pointed out the results:

  • Customer acquisition costs are ten times higher in the U.S. vs. Germany, $0.67 vs. $0.06, and “overhead” adds up to $1.24/W, or $5,000 for the average system (Solar Freedom Now)
  • $0.22/W on average for permitting + inspection + interconnection, including $0.09/W in fees (NREL)
  • Local permitting and inspection adds $0.50/W, or $2,500 per residential install, and nearly a month of delays (SunRun)
  • Labor costs alone add $0.11/W, and eight weeks average permitting time (Clean Power Finance)

The new LBNL study (PDF summary here, slides here) assembles permitting process scores from the DoE’s Rooftop Solar Challenge, the California Solar Initiative, and U.S. Census Data. All told it encompasses more than 3,200 residential PV systems installed in 44 California cities during 2011, representing 27 percent of the state’s total population and 20 percent of the state’s PV systems sized <10 kW installed in that year.

Essentially, the study boils down to one equation: permitting processes translate into time and money invested into a solar PV installation. Cities in California with the most favorable permitting practices, for example, have average residential PV prices that are 27-77 cents/W lower (4-12 percent of median PV prices in the state) than cities with the most “onerous” permitting processes. And average development times in those solar-friendlier communities are around 24 days shorter, or 25 percent of the median development time.

This study clearly illustrates the second-level effects of difficult permitting processes, notes Barry Cinnamon, cofounder of Solar Freedom Now. Certain cities are known to be difficult and expensive to work in, so installers actively avoid working there, he added. (The Clean Power Finance installer survey also came to this conclusion.) And that 27-77 cents/W figure implies a total system cost of about $0.50-$1.00/W range, which he called “pretty realistic.”

Cinnamon offered an example of differences in city permitting processes (and why solar PV installers need to know local laws). The city of Cupertino, Calif., has a particularly rigorous “fire setback” rule, requiring three feet of walkway around a roof’s edge. For a given rooftop, and solar panels several feet high, that could translate to a rooftop solar PV system restricted to a single row of panels. In nearby San Jose, an identical system not so restricted in fire setback might allow a second row of panels — meaning the potential difference between a 2-kilowatt (kW) system and a 4-kW rooftop system.

Lead image: Map of California, via LBNL