Environmental groups argued at the state Court of Appeals yesterday that state regulators erred when they approved new rules and rates for rooftop solar installations and that the changes hurt the state's solar industry.
Duke Energy had sought to lower what solar customers get paid for excess electricity sent to the power grid — what's known as "net metering."
It also wanted a new 10 dollar monthly rooftop solar fee. Regulators agreed and the new rules took effect October 1st for new solar installations.
The Environmental Working Group, NC WARN and other groups argue that the North Carolina Utilities Commission violated state law by not conducting an independent study of rooftop solar's costs and benefits.
Lawyer Matthew Quinn said regulators instead improperly used Duke Energy's own internal study.
"So our position is that when we use the word investigation, it can't be (that) Duke investigates itself," Quinn said. "It can't be the fox guarding the henhouse."
The environmental groups say the changes are already slowing solar installations. But lawyers for the utilities commission and Duke defended the process.
"The General Assembly did not explicitly require the commission to conduct an investigation prior to its establishment of these net metering rates," Robert Josey with the utilities commission public staff said.
Duke Energy argues that the previous rates unfairly subsidized solar owners at other customers' expense. A ruling in the appeal could take months.