Strata Solar, a Chapel Hill company, announced Friday it plans to build two solar farms in North Carolina that would be among the largest such power plants in the state.
Each farm would generate almost 5 megawatts of power, similar to the output of three previously announced facilities. One would be in Robeson County in the southern part of the state. Its customer would be Progress Energy.
The other would sell its output to Duke Energy in Catawba County in Western North Carolina.
Strata Solar's proposals require approval from the N.C. Utilities Commission. The company expects them to begin generating electricity next year.
John Morrison, chief operating officer at Strata Solar, said 5 megawatts has become the new measure for a large industrial-scale solar farm, replacing the unofficial old standard of 1 megawatt.
A single megawatt seemed an insurmountable solar barrier just a few years ago.
"The reason 5 is the new 1 is there are a lot more investors coming into the marketplace," Morrison said. "It's in the range that's financeable."
Another reason is the falling price of photovoltaic panels. Morrison said solar panels used to cost about $4 a watt three years ago but now cost about $1.10 a watt and are still falling.
A 5-megawatt plant is enough power for about 500 homes on average. Solar farms must account for not generating electricity around-the-clock, but only when the sun is shining.
Strata Solar has previously announced a 4.5-megawatt solar farm in Cleveland County, expected to begin generating power around Thanksgiving.
A solar farm of that size costs about $20 million to build, Morrison said. However, more than two-thirds of the cost is covered by subsidies, making such projects financially viable.
The subsidies include a 35 percent North Carolina state tax credit, a 30 percent federal tax credit and premiums utilities pay to meet state renewable energy mandates. The premiums are called renewable energy certificates.
The state's biggest solar farm is a 15.5-megawatt plant in Davidson County.