Coal is the world’s most abundant energy resource.

The federal Energy Information Agency estimates mineable global coal reserves exceed 1 trillion tons. Accessible coal in the United States—about one-quarter of the world’s reserves—would last for 222 years at current demand rates.

But government environmental regulations, market forces, and changing consumer expectations, particularly over the past decade, are pushing energy companies, including some electric co-ops, away from coal and toward natural gas and renewable resources.

Some generation and transmission cooperatives are using advanced generation facilities and favorable market conditions to continue to provide reliable and affordable coal-based power. But others are making big changes.

Between 2014 and 2019, electric cooperatives retired or converted to natural gas nearly 1.6 GW of coal capacity, with another 2.5 GW of retirements announced through 2025.

This transition has led to concerns about maintaining long-term energy security and grid reliability.

“The reliability of the entire grid becomes more challenging if you’re removing this resilient form of electricity,” says Jason Bohrer, president and CEO of the Lignite Energy Council, a Bismarck, North Dakota-based industry association. “If you remove coal-based generation, grid stability and fuel security will require new and innovative solutions to continue to meet consumer demands for high-quality electric service.”

Generation and transmission cooperatives and their members have spent billions on technologies that remove pollutants from flue gasses. Mirroring a trend across the electric sector, carbon dioxide (CO2) emissions from co-op-owned power plants were cut by 20.4 million metric tons between 2005 and 2017.

But perhaps most promising for the long term is the work that co-ops and other utilities have been doing with government agencies and private industry to develop and test cost-effective technologies that can capture and store or use the CO2 from power plant emissions.

“Cooperatives have made investments in plant enhancements and environmental controls that others in the industry did not make before shifting production away from coal,” says Jim Spiers, NRECA’s senior vice president for business and technology strategies. “As consumer-owned power providers, we’ve been at the forefront in investing in this infrastructure and are now examining additional approaches to get maximum value from these investments while also positioning the current fossil fleet to support continuing evolution of technology and the grid.”

‘Project Tundra’

Minnkota Power Cooperative has operated Milton R. Young Station since 1970 and has invested about $425 million there to meet current emissions control standards.

Since 2015, Minnkota has worked with the Lignite Energy Council, the state of North Dakota, the Department of Energy (DOE) and other interests to develop Project Tundra, a carbon capture and storage initiative with the potential of capturing more than 90% of the CO2 emissions from the plant’s Unit 2 generator and injecting it more than a mile beneath the plant for safe and permanent storage.

“It’s really gone from a concept phase to the advanced stage of research and development, and it’s very exciting,” says Stacey Dahl, the G&T’s senior manager of external affairs. “This has the potential to mitigate risk and enhance the value of our assets for our membership.”

Last year, Minnkota received a commitment of $9.8 million in DOE funding, clearing the way to access another $15 million from North Dakota’s Lignite Research Fund, approved in 2018. The money will be used for the final stage of engineering and design of the carbon capture facility and for subsurface mapping and permitting of the underground storage components.

Dahl says the co-op is focused on storage at the moment, but sees enormous potential for using captured CO2 in the region’s oil fields. CO2 can be used in so-called “enhanced recovery” techniques that have thus far not be deployed widely in North Dakota’s Bakken fields.

“If we can advance the research and development to further understand how CO2 will work in those shale oil formations, the need could outpace the amount of CO2 we can produce in North Dakota,” she says.

‘Real-world testing’

In Gillette, Wyoming, Basin Electric Power Cooperative has transformed its Dry Fork Station power plant into a hotbed of carbon capture research.

Dry Fork is home to the Wyoming Integrated Test Center (ITC), which conducts utility-scale CO2 research and commercial testing. It’s also one of the host sites for the $20 million NRG-COSIA Carbon XPRIZE, where participants are competing to develop commercially viable products using carbon dioxide from the plant. ITC research is also supported by Tri-State Generation and Transmission Association, NRECA, and JCOAL of the Japan Coal Energy Center.

“The ability for the researchers to conduct real-world testing at an active power plant alleviates typical concerns over being able to transfer technology from a lab to a plant,” says John Jacobs, Basin Electric’s senior vice president of operations. “Researchers have access to 20 MW of scrubbed flue gas.”

Dry Fork Station is among the nation’s most modern power plants, and Basin Electric has made numerous investments in coal-based generation research being conducted across its service territory.

Late last year, Basin’s board approved a three-year commitment to Phase III of Wyoming’s CarbonSAFE program. The University of Wyoming is applying for DOE grant funding to continue and extend ITC’s work, bolstered by up to $1.5 million in cash and in-kind contributions from Basin.

‘The Holy Grail’

Coal proponents agree that the “Holy Grail” of CCS research is the ability to efficiently capture power plant CO2 and convert it to commercially viable products and feedstocks for industrial use.

“Resolving the CO2 emission issue matched with a byproduct revenue stream would help keep coal, with its abundant availability, competitive with other forms of generation,” Jacobs says.

Finalists vying for the NRG-Cosia Carbon XPRIZE are pursuing commercialization of CO2-based compounds for use in environmentally friendly building materials such as concrete and graphene; biofuels for the transportation industry; nutrients for aquaculture and agricultural use; and personal care products.

Other teams are involved in using CO2 in nanofiber production for use in textile products, plastics, and other production materials. Research into CO2 use in methanol production for low carbon fuels is also under way.

Innovate and adapt

Additional work to maintain the nation’s coal fleet includes DOE-supported research by Great River Energy, NRECA, and Purdue University that looks at how power plant boilers are impacted when they are repeatedly ramped up and down as more wind and solar generation are integrated onto the grid.

“As more and more variable resources are added to the grid, stability and security will require [baseload] resources,” Spiers says. Knowing how key plant components respond under new grid demands will “provide more economic value and give extended life to plants.”

The pressure on coal is disruptive, Spiers says, but it’s activating co-ops’ innate ability to innovate and adapt.

Tri-State Generation and Transmission, Basin Electric, Hoosier Energy, and Dairyland Power all have announced near-term plans to retire major coal assets and integrate more renewables.

For G&T’s like Associated Electric Cooperative in Missouri, coal facilities remain an economical, reliable choice in their market. Associated’s strategy includes using the lowest-cost resources first—typically hydropower when it’s available—then coal, natural gas, and wind.

“Certainly for cooperatives, these are interesting times, with both challenges and opportunities” that vary from region to region, Spiers says. “The needs of the grid continue to require the capacity that’s been historically available from large central station power plants.”

He says the focus of G&Ts on serving the interests of their consumer-members and meeting the needs of the electric grid will drive them to keep seeking solutions to the baseload and reliability question.

“We see co-ops continuing to make investments and research new solutions because they believe it’s the right thing to do for their members,” Spiers says. “The impact carbon capture and other research could have on our industry and our country, if it bears out, is enormous.”