Santee Cooper’s rate hikes were higher than previously thought, an analysis shows.

Residential bills may rise $195 to $647 a year to pay for its failed nuclear project, Ellen Weaver of the Palmetto Promise Institute said.

Santee Cooper is the primary source of electricity for Mid-Carolina Electric members and those of other cooperatives in the state.

Palmetto Promise Institute is an independent public policy research nonprofit.

Santee Cooper’s 2017 financial statements exposes a dire need for state lawmakers to act, Weaver said.

“Our revised estimate shows Santee Cooper customers’ rates will need to increase between 13% and 45% to pay the $8.5 billion in total debt,” she said.

“This means the average annual residential bill will increase $195 to $647 and that increase will last for at least the next 38 years.”

Santee Cooper admitted customer rates must increase by at least another 7%, she said. Rates have already increased 15.2% since 2012.

“Santee Cooper does not have any equity stakeholders. This means the entire burden of the failed V.C. Summer project will be passed entirely on to customers,” said Katie Player, coauthor of the analysis.

Weaver said, “Santee Cooper’s current plan to delay rate increases only ensures even higher electricity bills down the road.

“We risk leaving $8.5 billion of debt solely on the backs of Santee Cooper ratepayers – South Carolina families and businesses.”