As North Carolina races toward the top of national rankings for solar energy, an Asheville company has proposed a dozen solar megafarms.
North Carolina is the nation’s fourth-largest state for installed solar capacity, a boom built on its green-energy mandate, tax credits and plummeting panel prices.
Most of that capacity has come from solar farms of less than 5 megawatts, a size that lets developers sell their energy to utilities at a “standard offer” set by the state.
Innovative Solar Systems wants to take that concept in a large new direction. The 3-year-old company has filed applications for 12 solar farms of between 25 and 80 megawatts, mostly in Eastern North Carolina.
Farms of that size would require hundreds of acres of leased land and negotiated interconnection and power-purchase agreements with utilities.
If all of the proposed ISS projects were built, the farms would have a total capacity of 620 megawatts, compared with the 750-megawatt capacity of the new natural gas-fired power plant Duke Energy will build in South Carolina.
Unlike gas plants, which run when they are needed, solar capacity is theoretical because electricity is generated only intermittently.
“It’s economies of scale” in building large, said John Green, an ISS co-owner. “You get better deals on equipment, have fewer legal costs, fewer soft costs. Large is like anything in life – the bigger you build, the cheaper the costs.”
Green predicts that “a very large number” of the proposed farms will be built.
State records show that ISS has previously registered 12 solar projects smaller than 2 megawatts in the Asheville region, selling the energy to Duke Energy or the former Progress Energy. ISS said this month that it has signed an interconnection agreement with Duke Energy for a 35-megawatt solar farm in Cleveland County.
In February, Duke issued a request for proposals for 300 megawatts of new solar capacity – and specified projects larger than 5 megawatts. Commercial unit Duke Energy Renewables announced a 20-megawatt project in Halifax County in November.
“There’s no magic number for (the size of) solar projects,” said Duke spokesman Randy Wheeless. “There are economies of scale that we believe make them more attractive.”
One of the state’s largest developers, Chapel Hill-based Strata Solar, builds what it calls “community-scale” solar farms. Its website shows 57 projects, none larger than 7 megawatts.
Under the state’s renewable-energy portfolio standard, construction of solar projects less than 2 megawatts have only to be reported to the North Carolina Utilities Commission. Those less than 5 megawatts have to provide more information on the financial viability of the project.
While some large solar farms are already operating, such as Apple’s 20-megawatt farm in Catawba County, the larger projects take longer to complete and require more land leases, said Betsy McCorkle, a lobbyist with the North Carolina Sustainable Energy Association. That might scare off some investors, she said.
Under federal law, utilities have to buy the electricity produced by renewable energy projects of up to 80 megawatts. But in North Carolina, those of more than 5 megawatts have to negotiate with utilities over the power purchase price and interconnection terms.
In a proceeding now before the Utilities Commission, Duke has proposed lowering the size of projects able to get the “standard offer” for power purchases from the current 5 megawatts to the much smaller 100 kilowatts.
The commission will arbitrate a case in June in which the developer of a 20-megawatt Montgomery County solar farm claims Duke Energy Progress unfairly lowered its power purchase offer.