Holy grail of carbon capture continues to elude coal industry

Hopes for carbon capture and storage (CCS) technology have been a key policy driver at the U.S. Department of Energy for more than a decade, promoted initially as a way to cut carbon dioxide (CO2) emissions that cause climate change and now, under the Trump administration, as an unabashed means of propping up the declining U.S. coal industry.

Billions of dollars have been spent for carbon capture research and development in North America, and rosy predictions for CCS have been ritually repeated year in and year out.

However, today, 15 years after CCS development work began in earnest, there remains only one operational coal-fired carbon capture project in the U.S: NRG’s experimental Petra Nova project south of Houston. A second North American CCS plant, the Boundary Dam Power Station owned by Saskatchewan Power (SaskPower), is in operation in Canada.

In this report, we examine CCS-related projects at four North American coal-fired power plants.: Petra Nova, Boundary Dam, Southern Company’s Kemper project in Mississippi, and Duke Energy’s Edwardsport plant in Indiana.

Petra Nova and Boundary Dam involve post-combustion CO2 capture. Kemper, by contrast, was designed originally as a coal gasification unit with pre-combustion removal of CO2, but both its gasification and CO2 capture components have since been dropped. The Edwardsport plant, which was initially promoted for its capability to capture CO2, later abandoned the idea because of its high cost. It is included here for its gasification technology, which is an essential component of pre-combustion CO2 capture.

While Petra Nova and Boundary Dam are operational, both are really only demonstration units. Petra Nova captures just over a third of the flue gas from one of four coal-fired units at the massive W.A. Parish Plant, and it has been an expensive experiment, at a cost of more than $1 billion. Boundary Dam, the smallest of the four projects examined here, has been plagued by operational problems and cost overruns that have pushed its price tag to roughly US$1.1 billion. Further, both Petra Nova and Boundary Dam rely economically on selling their captured carbon for enhanced recovery operations (EOR) in oil fields, an option that is not necessarily available to coal plants elsewhere.

The integrated gasification combined cycle projects at Edwardsport and Kemper have been disasters, as they proven absurdly expensive to build and costly and unreliable to operate.

Widescale use of CCS would require a huge network of pipelines (and associated infrastructure) to transport captured CO2 to sequestration sites, an issue given scant attention in CCS development discussions. Such a network would be enormously costly and extremely time-consuming to permit and build. Further, Capturing CO2, piping it to distant sequestration sites and injecting it into the ground would require an exorbitant amount of water.

We note also in this report that the aging U.S. coal fleet would require costly upgrades to accommodate CCS retrofits. More than half of the fleet is already more than 40 years old; significant rebuilds would be required for owners to ensure that their facility could operate for the 20-30-year lifespan of any new CCS equipment. This phenomenon is already on display at Boundary Dam, where SaskPower spent more than US$330 million to rebuild the power block at the plant to ensure its operational lifespan would match that of its CCS retrofit. Such investments are site and plant specific, negating any potential economies of scale.

The CCS experiments described here have unfolded against the backdrop of an electricitysector revolution driven by increasingly low-cost, zero-emission wind and solar and plentiful and relatively low-cost natural gas supplies.

As it is, coal plants without CCS are having an increasingly difficult time competing with wind and solar resources. Adding a $60 per ton cost for CO2 capture, or even the $30 per ton cost that advocates say can be achieved, will further undermine coal’s ability to compete.

These larger trends further undermine the economics of CCS retrofits. Adding CCS costs to units that aren’t even operating now full time will only lead to increases in per-unit costs, creating a spiral that feeds on itself, rendering plants increasingly uneconomic and turning CCS equipment into stranded assets. The utility industry, well aware of what is occurring in power-generation markets nationally (and internationally) and pushed by consumers big and small to modernize, is now moving rapidly away from baseload coal and toward a cleaner, more distributed-energy future, making carbon capture an increasingly outmoded concept. In short, where high-risk, high-dollar carbon capture investments may have made sense at one time, today they do not— and indeed the high cost of carbon capture will most likely remain prohibitive.

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While this report focuses on U.S. electricity markets, our findings serve as a cautionary tale for any country considering broad adoption of CCS. The technology remains unproven at full commercial scale, it is wildly expensive, there are serious questions regarding the aftercapture transport, injection and storage of the captured CO2 and—most important—more reliable and far cheaper power-generation options exist.

Press release: If Chevron, Exxon and Shell can’t get Gorgon’s carbon capture and storage to work, who can?

Please view full report PDF for references and sources.