Study Examines Savings from Residential Photovoltaic Systems

Lawrence Berkeley National Laboratory, January 29, 2013

A new Berkeley Lab report, "Electricity Bill Savings from Residential Photovoltaic Systems: Sensitivities to Changes in Future Electricity Market Conditions", explores long-term uncertainties in the utility bill savings that customers receive from photovoltaic systems.

Specifically, the report evaluates how changes to wholesale electricity market conditions may impact retail electricity prices and rate structures, and how those changes may in turn affect the bill savings that customers with PV receive under net metering and other kinds of compensation mechanisms. The principal findings of the analysis include:

• The utility bill savings from resideential PV increase with higher levels of renewables on the grid, if compensated via a flat rate with net metering.

• The bill savings from residential PVV decline with increasing solar penetration levels on the grid.

• Among the three retail rate structurres considered, the time-of-use rate provides the greatest bill savings value under electricity market scenarios with relatively low solar penetration levels on the grid, while the flat rate provides the greatest bill savings under high solar penetration scenarios.

• With high solar penetration levels oon the grid, the bill savings from residential PV increase with greater deployment of grid storage, demand response, or concentrated solar power with storage.

• The bill savings are significantly eeroded if, instead of net metering, generation from behind-the-meter PV exported to the grid is compensated at hourly wholesale prices.

http://emp.lbl.gov/sites/all/files/lbnl-6017e.pdf