When it was dedicated in January 2014, the Colleton Solar Farm was the largest solar installation in South Carolina’s history. The historic project is a joint venture between the state's electric cooperatives, TIG Sun Energy and the state-owned utility Santee Cooper. TIG Sun Energy owns and operates the 3-megawatt complex. Santee Cooper purchases the electricity in collaboration with Central Electric Power Cooperative, the wholesale power purchaser for the state's 20 independent distribution cooperatives.
The solar array has 10,010 photovoltaic (PV) panels, located on 15 acres of former farmland adjacent to Interstate 95 near Walterboro. At peak generation, the 3-megawatt complex produces enough electricity to power more than 250 average sized homes.
In its first year, through December 20, 2014, the site generated 4,687 megawatthours (MWh), 5 percent more power than projected before construction. The extra 5 percent may not seem like much, but it’s the equivalent of lighting 1,200 60-watt bulbs for eight hours a day.
In year two, the production of the solar farm decreased 10 percent, to 4,281 MWh. Energy output plunged in the summer of 2015 because of extended rainy periods – demonstrating the intermittent nature of the resource.
Not all solar panels are created equally. At the Colleton Solar Farm, 60 percent of the panels are in a fixed position. The panels are tilted at an angle, and once installed, remain affixed. The other 4,000 panels at the farm use a single axis tracking technology. This mechanical feature allows these rows of panels to follow the sun across the sky throughout the day. The panels move incrementally throughout the day, capturing as much of the sun’s rays to maximize its daily output of energy. Though tracking panels are more expensive to install initially, it was a wise investment for the Colleton Solar Farm. After one-year of operation, the electricity produced by the tracking panels costs 9 percent less per kilowatt-hour (kWh) than the power produced by the panels that did not move.
The Colleton Solar Farm builds on a 15year renewable energy history for Santee Cooper and the electric cooperatives. The utilities began generating and distributing renewable landfill gas energy in 2001, and since then have steadily increased renewable generation, using homegrown, South Carolina resources.