Duke Energy and 33 utility-scale solar developers have signed an agreement on grid connection criteria after a dispute over how they were applied.
Solar arrays in the top two solar states, California and Arizona, often are sited in remote areas where their energy can connect to high-voltage transmission lines. North Carolina’s solar farms are most often built in rural places served by lower-voltage distribution systems.
“In some areas of our system we’re reaching a saturation point with solar, and in some places it is ill-placed,” said Duke spokesman Randy Wheeless. Too much energy from solar farms may flow into some circuits, he said, while elsewhere the off-and-on nature of solar power causes energy fluctuations for customers.
Solar developers sometimes had to pay for upgrades to substations to fix those problems.
Duke owns 500 megawatts of solar capacity in North Carolina and has long-term power purchase contracts for another 1,300 megawatts. Solar developers are lined up to add up to 3,300 additional megawatts.
In July Duke notified developers that it will require more study of connection requests, to make sure local distribution systems are able to support them.
Owners of solar farms in the late stages of development protested. The agreement reached Monday allows projects that failed to meet the new criteria to go forward but gives Duke the right to disconnect if problems occur.
“We think it will allow developers to take even closer looks at their projects, as well to bring better projects forward,” Wheeless said.