Santee Cooper’s 164,000 electric customers in eastern South Carolina will see their bills rise 7 percent in the next two years, starting in December.

Rates will rise an average 3.5 percent Dec. 1 and again on Dec. 1, 2013.

The state-owned utility’s board of directors on Tuesday approved the two-year rate hike to help pay for the expansion of V.C. Summer Nuclear Station, which Santee Cooper co-owns with South Carolina Electric & Gas Co., and to meet the costs of new environmental regulations.

The proposed rate increase, a first since November 2009 and only the second since 1996, was announced in May. The board’s vote followed several public hearings during the summer in its direct customer coverage area in Berkeley, Georgetown and Horry counties.

For the average home using about 1,000 kilowatt-hours of power, the electric bill will go up $5.60 per month the first year and an additional $8.29 per month the second year. The average Santee Cooper residential electric bill is about $107.05 a month.

“In considering this rate adjustment, the board reviewed an independent rate analysis, management’s proposal, and the comments and input we received from the public,” Santee Cooper Chairman O.L. Thompson said.

“I know that times remain tough for many of our customers,” he said. “The fact is, Santee Cooper has already cut or deferred $1.8 billion in capital expenses and approved other cost-saving measures the past two years. We are now at a point where we must increase revenues to ensure we can fulfill our statutory requirements to recover our costs, meet new environmental regulations and build generation that is important to South Carolina’s future.”

The rate hike affects residential, commercial, industrial, municipal and lighting customers. It will not affect wholesale customers such as electric cooperatives, who buy their power from the Moncks Corner-based utility.

Without the rate increase, Santee Cooper officials said they would fall $17 million short of revenue in 2013 and another $31 million behind in 2014.

Santee Cooper owns 45 percent of the new $10 billion nuclear project in Fairfield County and its portion amounts to about $4.5 billion.

Read more in Thursday’s editions of The Post and Courier

Reach Warren L. Wise at 937-5524 or twitter.com/warrenlancewise.