South Carolina Electric & Gas Co. didn't fare so well in the latest independent customer satisfaction survey.

The Cayce-based utility that serves much of greater Charleston ranked in the bottom tier of the South region large utility segment in the J.D. Power 2014 Electric Utility Residential Customer Satisfaction Study.

Large utilities, based on the study, are those with more than 500,000 customers. SCE&G serves more than 673,000 customers across the state. About half of those are in the Lowcountry.

Of the 13 utilities in the group, SCE&G came in 10th. Only two Duke Energy divisions and Tampa Electric scored lower. SCE&G's score: 638 on a 1,000-point scale.

SCE&G spokesman Eric Boomhower said he could not address the results because the utility did not purchase the survey data for the study.

He pointed to another recent survey from energy research company Market Strategies International, which competes with J.D. Power, that called SCE&G one of the most-trusted electric and gas utilities in the nation, ranking second overall in the South.

"We use the collective insights gained from these types of reports, along with numerous other customer research tools, to work toward continuous improvement of the programs and services we offer our customers," Boomhower said.

One possible reason for SCE&G's low J.D. Power rating is the seemingly endless round of price hikes to pay for the utility's 55 percent portion of the $10 billion two new nuclear units at V.C. Summer nuclear station in Fairfield County north of Columbia.

The average annual 2.36 percent price hikes continue for 10 years through 2019, a year after the two units come online. SCE&G says the annual spikes are meant to help defray construction costs as the reactors are built rather than springing the hike on ratepayers when they are completed.

The state Public Service Commission and Office of Regulatory Staff are currently considering the utility's request for a 2.99 percent jump in electric rates to help pay for the nuclear units. If approved, the rate increase generally appears on SCE&G customers' bills in late fall.

State-owned utility Santee Cooper is SCE&G's partner in the nuclear project. It scored in the top tier of 24 mid-sized utilities in the South region, coming in seventh with a score of 702. Walton Electric Membership Corp. in Georgia scored the highest at 735. Entergy New Orleans ranked the lowest with a score of 610.

But it's not all bad news for SCE&G. All of the other utilities in its group took home scores in the 600s as well. OG&E, or Oklahoma Gas & Electric, scored the highest in the category at 696. Duke Energy-Florida scored the lowest at 610.

"Residential electric utilities have done a great job adding capabilities for proactive communications about outages and upping their corporate citizenship involvement. As a result, customer satisfaction levels have been improving over the past several years," said Jeff Conklin, senior director of the energy practice at J.D. Power.

"However, when comparing satisfaction levels with many other service industries - such as television and telecommunication in which there is a physical connection to a home with a monthly bill payment arrangement - electric utilities are not improving at the same pace in overall satisfaction," Conklin said. "Consumers are becoming more familiar with a higher level of service in their daily activities with other service providers and, as a result, their expectations are rising."

J.D. Power surveys several other service industries, but it says overall satisfaction in the electric residential study is growing at the lowest average rate - 4 index points per year over the past five years.

By comparison, customer satisfaction with residential television service providers such as cable TV has increased by an average of 17 index points per year during the same time frame (to 699 on a 1,000-point scale in 2013), while satisfaction with residential Internet service providers has increased by 10 points per year (to 683 in 2013), J.D. Power said.

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