— Key hearings on Duke Energy's request to raise household electricity rates 16.7 percent, once slated to begin today, has been delayed a week as government attorneys tasked with representing the public negotiate with the electric utility.

The change would increase the typical residential bill $17.80 a month, or about $214 a year. That includes a significant increase in the base rate people pay regardless of how much power they use.

The company says it needs the boost to cover a slew of system improvements, coal ash basin cleanups and storm response following Hurricane Matthew. If approved by the state's Utility Commission, the increase would bring an extra $477.5 million in annual revenue to Duke Energy Progress, which serves the eastern half of North Carolina, including Wake County.

The company also seeks an increase in the return on equity it's allowed as a regulated monopoly, going to 10.75 percent instead of the current 10.2 percent.

A separate rate case for Duke Energy Carolinas is pending for next year, seeking similar increases and another $611 million in annual revenue for the company, which serves much of the western part of the state, as well as Durham and much of Orange County.

Both Duke Energy Carolinas and Duke Energy Progress are owned by Duke Energy.

These matters are typically heard in a court-like setting, with multiple sides making arguments on the proper rates the regulated monopoly should be allowed , and appointed commissioners acting as judge. Just what issues may be settled in the Duke Energy Progress case was unclear over the weekend, but a late Friday order from the commission indicated a partial agreement would be released on Monday. Whatever issues remain could be litigated beginning October 27, according to the order, which was forwarded to NC WARN and other parties Friday evening by a Duke Energy attorney.

For NC WARN, an environmental advocacy group set to argue against the request, the delay recalls other recent rates cases settled prematurely, Executive Director Jim Warren said.

"This continues a long standing out rage," Warren said via email. "The regulators cut a back room deal with Duke energy that undermines everyone else’s work and screws up everyone’s schedule."

Public Staff Chief Counsel David Drooz said Monday that a staff-backed settlement doesn't keep others in the case, including the North Carolina Attorney General, from pressing the case.

Large customers facing industrial and commercial increases of about 13.5 percent were set to fight the requested increase along with NC WARN. Among the arguments: Company shareholders, not ratepayers, should cover cleanup costs at toxic coal ash pits built over decades near coal-fired electricity plants around the state.

NC WARN has also keyed in on an increase Duke seeks in the flat monthly fees it charges regardless of usage, which would go from $11.13 a month to $19.50 for residential customers. That charge is meant to cover infrastructure costs for providing service, and the adjustment is needed to "get us closer to what it actually costs us," Duke spokesman Jeff Brooks said Friday.

A lengthy case file in Duke Energy Progress' case is available online and replete with expert testimony and complex calculations delving into how much Duke should charge. The potential settlement may "eliminate the need for a substantial amount of cross-examination of witnesses," the commision said in its order Friday.

The commission already has held public comment hearings in this case, and the file includes dozens of written complaints from people upset over the prospect of an increase.

"It seems that at every opportunity, Duke charges," J.H. Beveridge of Canton wrote in an email to the commission. "And as there is no competition in my area, they have a monopoly. There can be no justification for a rate increase. Captive consumers should not have to pay for coal ash spills, mismanagement or excessive corporate salaries."

A number of commenters mentioned coal ash cleanups. Brooks said Duke isn't trying to recoup costs from a 2014 ash spill in the Dan River but for state-mandated cleanups at other ash pits across the state. He said the average user generates 150 pounds of coal ash a year, an amount cut in half over the last five years as Duke moved to more natural gas power generation.

"It's important to understand that customers have benefited from electricity generated from coal for decades," Brooks said. "Coal ash is the byproduct. We generate it every time we flip on a light switch."

Warren said Duke is trying not just to recoup costs for "past coal ash debacles," but for future ones. His group will also argue that state law doesn't allow the company to charge customers for costs stemming from unlawful activities, lawsuit settlements or criminal convictions.

"It is clear that there were violations of water quality standards at all of the coal ash impoundments. This is what precipitated the subsequent court orders for cleanup efforts," NC WARN has argued. "If Duke Energy believed the closing of the coal ash basins is part of the life cycle of its coal plants, it should have phased the cleanup over the past several decades rather than burden ratepayers with the rate shock of cleaning up all of its failures over a short time."