Time running out for rooftop solar benefit

The sun is setting steadily on California’s super-incentive for rooftop solar.

Customers of San Diego Gas & Electric have reached the half-way point toward a cumulative cap on a program known as net energy metering, the utility reported on its website.

Under net metering, rooftop solar customers of California’s major investor-owned utilities are credited for excess electricity at the full retail rate. The arrangement effectively winds a household electric meter backwards, allowing some customers to pay next to nothing on electricity bills or even earn some money after a 12-month period.

California’s investor owned utilities are phasing out the current version of net metering. New rooftop solar customers can still lock in the deal for a 20 year period. But they must act before utility regulators modify rules or before rooftop solar capacity expands to 5 percent of the region’s peak electricity usage -- whichever comes first.

As of Sept. 30, rooftop solar installations and registered applications accounted for about 2.5 percent of peak demand, or half-way toward the cap. State law says the new regulations must be in place by mid-2017.

The current net energy metering program combined with rapidly rising utility rates has fueled growth in California’s rooftop solar industry, both residential and commercial. But utilities including SDG&E say it has allowed solar customers to avoid paying for their fair share of grid construction and maintenance costs.

SDG&E is required to update its progress toward the net metering cap each month. It does so here: https://www.sdge.com/clean-energy/net-energy-metering/overview-nem-cap.

The economic rewards of rooftop solar are shifting as California moves toward unavoidable fixed fees and time-based electricity charges. The California Public Utilities Commission is in the early stages of designing a successor tariff to current net metering.