South Carolina electric co-op pursues batteries and other alternatives to a proposed gas unit

South Carolina’s Central Electric Power Cooperative will not participate in a new gas-fired generating unit that utility Santee Cooper has proposed, to replace coal-fired units at a site near Georgetown, South Carolina.

Instead, Central plans to replace its share of about 1.1 GW of capacity from retiring coal units through power purchase agreements, utility-scale batteries, distributed energy resources, and participation in future power plants built in the state.

Central described utility-scale batteries as “a technology proven to be technically possible and currently being pursued by utilities all over the country.”

Distributed energy resources, Central explained, are “batteries, generators and demand-side management programs, all aggregated to represent a utility-scale solution.” When aggregated, the resources “become utility-scale and can be counted on as predictable generation capacity. These resources would grow out of FERC Order 2222, which has accelerated their advancement to utility scale.”

Central is a generation and transmission utility that aggregates power supply for 20 electric distribution cooperatives serving 860,000 customer accounts. The cooperative owns community solar and peaking generators but obtains most of its power through long-term purchase agreements with Santee Cooper, Duke Energy Carolinas, and the Southeastern Power Administration.

“There was not a meaningful cost difference in the top options that are available,” the cooperative said in a statement, saying that its analysts “supplement cost considerations with broader strategic goals and include independent risk assessments. Central’s members say they want competitively priced wholesale power costs, reliable delivery of energy, and, increasingly, they want supplier and fuel diversity.”

“I think there were several members of the staff and certainly a number of our board members who were surprised” at the decision of the cooperative’s board, said Robert Hochstetler, Central’s president and CEO. “But we went where our requirements and the opportunities took us. The solution had to be affordable, the power supply had to be reliable, and we needed to be ready by 2029,” when the last coal unit near Georgetown is set to retire.

With Central’s board having approved the overall plan, the utility will develop a detailed plan over the next year, Hochstetler said.

Coordination agreement

Central has already sourced solar power directly, rather than through a joint arrangement with Santee Cooper, by entering contracts with solar developers.

Direct sourcing was made possible by a 2013 coordination agreement between Central and Santee Cooper, which allows Central to opt out of any proposed Santee Cooper generating unit, and to independently meet its power needs that would otherwise have been met by its share of Santee Cooper’s proposed generating unit.

Central now receives about 70% of its wholesale power supply from Santee Cooper, and beginning in 2029, it will still receive more than half of its power from Santee Cooper, the cooperative said, “continuing the long and significant relationship the companies have benefited from for decades.”

Joint resource planning with Santee Cooper has identified the need for additional solar generation to economically meet the needs of the Central-Santee Cooper system, the cooperative said, adding that it “looks forward to the opportunity to participate in that process.”

For more on South Carolina read 50 states of solar incentives: South Carolina.