press releases

New NARUC White Paper Explores Impacts of Changing Generation Mix on Coal Plants

View as PDF
For Immediate Release:

Contact: Scott R. Bolden, 202-898-8083,

New NARUC White Paper Explores Impacts of Changing Generation Mix on Coal Plants

WASHINGTON (January 24, 2020)—A new white paper commissioned by the National Association of Regulatory Utility Commissioners examines the impacts of changes in the electricity generation mix on operating coal-fired power plants.

Recent Changes to U.S. Coal Plant Operations and Current Compensation Practices explores the ongoing shift from coal generation towards natural gas and renewables. With 30 gigawatts of coal capacity having retired in the past two years, the report details how remaining coal plants are managing increasing pressure to act as load-following — or cycling—resources, particularly in states with high reliance on intermittent renewable generation. In Iowa, Kansas and Oklahoma, retiring coal was replaced almost entirely by new wind generation, whereas Georgia, Maryland, North Carolina, Ohio and Virginia replaced retiring coal with natural gas generation. How retiring coal is replaced has a bearing on the operations of existing coal plants, impacting capacity factors, frequency and duration of time offline, maximum turndown rates and hourly ramping rates. In addition to analyzing these changes, the report offers an overview of strategies for coal plant owners and operators to manage costs while providing flexible electricity.

"State energy regulators need to ensure that reliable power can be delivered to customers, regardless of whether or not the sun is shining or wind is blowing," said Chairman Kara B. Fornstrom of the Wyoming Public Service Commission, vice chair of NARUC’s Subcommittee on Clean Coal and Carbon Management. "This report looks at challenges faced by coal plants that are now operating as cycling resources, and presents options for operators and regulators."

“With significant coal retirements expected to continue in the future, an evidence-based assessment of the impacts of a changing fuel mix on existing coal plants is valuable for state energy regulators as they consider how to manage costs for customers,” added Danielle Sass Byrnett, director of NARUC’s Center for Partnerships & Innovation.

The report, developed under the Carbon Capture Storage and Utilization Partnership between NARUC and the United States Department of Energy, was authored by Phillip Graeter and Seth Schwartz, of Energy Ventures Analysis, Inc. To read the report, go to The authors will speak on an upcoming webinar, moderated by Fornstrom, on Monday, January 27, from 2:00 to 3:00 pm EST. To register, go to



NARUC is a non-profit organization founded in 1889 whose members include the governmental agencies that are engaged in the regulation of utilities and carriers in the fifty States, the District of Columbia, Puerto Rico and the Virgin Islands. NARUC's member agencies regulate telecommunications, energy, and water utilities. NARUC represents the interests of State public utility commissions before the three branches of the Federal government.