Market trends have led to many coal-fired power plants being retired. For smaller operators looking for ways to keep plants viable, carbon capture technology might offer possibilities that are increasingly worth a second look.
In 2018, Congress approved revisions to the existing Section 45Q tax credits for carbon capture and storage. Those revisions offered greater credits per ton of CO2 captured and lower thresholds for who is eligible for those credits. Those changes are making implementation of carbon capture technology more cost-competitive in the market today.
Under those circumstances, we have been helping a client look at the feasibility of implementing carbon capture technology at an existing coal-fired plant. The client was selected for a $15 million industry grant, contingent upon another $15 million the client has applied for from the U.S. Department of Energy.
The technology involves taking the flue gas from a coal stack, cooling it down and sending it through a reactive absorber. An amine solution strips carbon dioxide from the flue gas. That rich amine solution is sent through a reboiler or regenerative process that strips to pure CO2 from the solution. Finally, that gas is compressed for storage or use elsewhere, such as an enhanced oil recovery (EOR).
At large scale, the upfront capital costs could be significant. Our client is looking at a creative approach to make things more efficient: integrating the carbon capture into existing plant operations. The new carbon capture facility, privately financed to monetize the tax credits, would rely on the sale of both steam and flue gas from the existing generation operations. The ability to draw on power and steam from a power plant next door would help offset costs.
Another challenge derives from taking a large percentage of the steam flow from the power plant turbine to send to the carbon capture facility. A significant reduction of power could result from the reduction in power production use of the steam. Balancing those competing needs with the power plant’s operational requirements would be a hurdle to address during project development and beyond.
The integration would provide challenges as well as opportunities, given the significant needs of the new facility. One would be determining how to capture and efficiently reuse the significant heat rejection to lower the cooling load for the overall facility. If the power plant lacked additional cooling capacity, a new cooling tower could be needed to support the new cooling load, representing a significant capital investment in its own right.
Find the Right Combination
As smaller power providers like cooperatives look for ways to extend the economic life of their facilities — and continue supporting jobs in their communities in the process — carbon capture technology is increasingly an option worth a second look.
With more manufacturers beginning to develop carbon capture technology, nascent competition could help make the technology more cost-effective. Combined with greater tax credit incentives and the potential efficiencies of greater integration with an existing plant, the path to a financially solvent project is looking a little more promising.
Carbon capture technologies make fossil generation more sustainable by making greater use of the byproducts of generation. Explore our perspectives on the potential power of renewable power and energy storage.