North Carolina regulators this week approved Duke Energy's latest 15-year energy plan as "adequate." But they also ordered the company next year to show why it still makes economic sense to keep old coal plants open and how it will help meet state goals for reducing greenhouse gas emissions.
Every year, North Carolina's utilities must update their Integrated Resource Plans, which forecast growth in energy demand and how they'll meet it. The latest plans approved this week for Duke Energy's two North Carolina units — Duke Energy Carolinas in the west and Duke Energy Progress in the east — call for more cleaner-burning gas-fired power plants and more solar energy through 2033.
And for the first time in recent memory, the plans don't include any new nuclear plants. Duke canceled nuclear projects in Florida and South Carolina two years ago.
But environmental groups think Duke isn't retiring coal plants fast enough to take advantage of falling costs for newer technologies like solar farms and battery storage.
"We're reasonably confident a significant number of the coal plants in North Carolina are uneconomic, meaning that Duke's customers are paying more for energy from those coal plants than they would if Duke just retired those coal plants and replaced them with clean sources like solar power," said Dave Rogers, regional director of the Sierra Club's Beyond Coal Campaign.
Duke Retires Plants
Duke has retired nine coal plants in the Carolinas in recent years, but still has seven, including the Allen Steam Station on the Catawba River west of Charlotte.
Rogers said it costs Duke $67 to produce one megawatt hour of electricity at the Allen plant — enough to power a typical house for a month.
But, Rogers said, "in Duke's most recent competitive bidding process, the average bid for new solar installations (was) around $37 or $38. So that's a pretty significant cost savings."
The North Carolina attorney general's office joined the critics, arguing that Duke’s plans for more natural gas plants are not justified and fail to consider economic and environmental risks.
Commission Wants New Modeling
The North Carolina Utilities Commission took many of those arguments to heart. It approved Duke's latest plans — known as the 2018 Integrated Resource Plan — as "adequate." But for the first time, regulators asked the company to present models for early retirement of coal plants and adoption of more renewables.
That's in part to help North Carolina meet Gov. Roy Cooper's Executive Order 80 of last October, which sets a goal of slashing carbon emissions in the state 40% by 2025, from 2005 levels.
Duke spokeswoman Meredith Archie said the company is already working on that.
"We've significantly reduced our carbon emissions in recent years by retiring coal and adding more renewables and cleaner natural gas and we're certainly transitioning to an even cleaner energy future," Archie said. "The commission in its order also wants us to evaluate the accelerated depreciation of our coal plants, which we are doing."
Duke must file an update to the 2018 plan by Sept. 1. Its next full Integrated Resource Plan is due Sept. 1, 2020.
You can read the N.C. Utilities Commission order on the Duke Energy and Dominion Energy 2018 Integrated Resource Plans at NCUC.net.