— An attorney for Duke Energy said Monday that rate increases benefit electric customers in the long run by guaranteeing the viability of the utility.

Chris Browning made the argument before the North Carolina Supreme Court while calling for justices to uphold a 7.5 percent increase that the state Utilities Commission awarded to Duke last year for former Progress Energy customers.

The state Attorney General's Office appealed the increase, saying the commission ignored an April 2013 Supreme Court ruling that struck down another Duke rate increase because consumer interests weren't considered.

Special Deputy Attorney General Bill Conley argued Monday that the former Progress customers were "an afterthought" in the commission's decision to raise rates, noting that the panel rejected a lower recommended increase because it would have hurt Duke investors.

Browning said the commission had to balance competing consumer interests, not just the short-term impact of a rate increase. The customers also are affected by Duke's ability to obtain financing for upgrades to its power generation and distribution network, and limited rate increases would hinder that capability, he said.

"No one ever wants to have a rate increase, but if a company doesn't have sufficient revenue and the company's ability to raise capital is put in jeopardy, it is customers that suffer in the long run," he said.

William Grantmyre, an attorney for the North Carolina Public Staff, the state agency that represents consumers in utility rate cases, backed Duke in the rate case, saying the Utilities Commission decision was in the best interest of the former Progress customers.

The Attorney General's Office has repeatedly challenged electric rate increases in recent years, saying that consumers are still hurting from the recession and can't afford higher utility bills.