Dominion Virginia Power will be able to charge large-scale residential solar customers a standby fee when their panels are not generating enough electricity, state regulators decided.
The State Corporation Commission announced Wednesday that Dominion Virginia Power customers who own and operate net-metered electric-generation systems ranging from 10 kilowatt hours to 20 kilowatt hours will have to pay the monthly standby charge.
The decision, which backs a state law enacted during the most recent session of the General Assembly, approves a standby-charge methodology that allows the company to recover its transmission and distribution costs because those customers still make use of the electric grid.
"This will affect very, very few people," said Dianne Corsello, manager of customer solutions and new technology at Dominion Virginia Power.
The solar systems that generate that much energy are very expensive to install, she said. But "as solar prices decline, there may be more customers who choose to put these large systems on their rooftops or on their property."
The standby charge does not apply to smaller-scale solar customers, the company said.
But solar-power advocates believe that the standby charge would be a deterrent to getting consumers to invest in renewable energy sources.
"Generating electricity from renewable sources, in this case solar panels installed on rooftops, is to be encouraged, not punished," J.R. Tolbert, assistant director of the Sierra Club Virginia Chapter, said in a statement.
"Charging its green-minded customers upwards of $60 per month is both excessive and punitive," he said.
Dominion Virginia Power said the monthly charge will not be as much as $60. It will be different for each customer and each month, Corsello said. The fee is $4.19 per kilowatt, she said.
The fee will be charged when a customer's solar panels are not generating enough electricity, typically at night, she said. Charging a fee covers the cost for using the utility's wires and equipment when self-generation isn't working.
The SCC said the electric grid must be available to deliver power to net-metered customer generators when their own solar or other forms of generation are not producing electricity and to return any excess power produced by eligible customer-generators' facilities.
In approving the methodology, the SCC said, "the evidence in this record indicates that any avoided cost benefits provided by customer-generators, at least in terms of the transmission and distribution grid, are insufficient to pay for their proportionate share of the grid."