Next month, Mississippi Power’s 582 MW Kemper coal plant with carbon capture is expected to begin commercial operation. When it reaches full capacity, Kemper will capture about 3 million metric tons of CO2 annually, which represents about 65% of the CO2 it produces. Over the last several years, I’ve gotten many questions about Kemper. Now that the plant is ready for operation, let me address the two most frequent ones.
Does the $7 billion cost of Kemper imply carbon capture is too expensive?
No. Kemper’s cost overruns and schedule delays are due to the construction of a “first-of-a-kind” coal gasifier, which is completely separate from the carbon capture equipment installed on the plant. So, the same cost issues would have been in play had there not been a carbon capture component to the project. Many press accounts of the Kemper plant have completely failed to make this distinction and, as a result, the misperception has been left that the carbon capture equipment on the plant led to high costs and cost overruns. In fact, the carbon capture equipment had little or nothing to do with the cost overruns.
The novel gasification technology used at Kemper is called TRIG. The TRIG gasifier was developed by KBR, Southern Company and the U.S. Department of Energy at the Power Systems Development Facility in Wilsonville, Alabama. Testing on a 6 MWe gasifier began in 1999 and was conducted for nine years before the decision was made to go straight to a first-ever, full-scale 582 MW TRIG design. However, as often happens the first time a technology is built, a few costly kinks had to be ironed out. Once construction began, Mississippi Power found it had to make major changes to the piping, including thickness, metallurgy, quantity, and supporting structures that drove up the cost. Other project delays and declining productivity of labor also added costs. These and other factors drove up Kemper’s price tag from a capped plant cost of $2.88 to $5.60 billion today. Adding in non-plant costs such as the lignite mine, CO2 pipeline and other costs increased the total expenditures to $7.1 billion.
But these cost overruns were not related to the CCS equipment. For all the “newness” that is sometimes asserted is attached to carbon capture, in fact this is a well-established technology. The capture technology used at Kemper is called Selexol, and it was developed in the 1950s. There are more than 110 Selexol projects in operation today, primarily at chemical plants.
By contrast, Petra Nova, a Texas carbon capture project that also went into commercial operation earlier this month, was finished on budget and on schedule. Unlike Kemper, the Petra Nova project is a retrofit of an existing coal plant, and thus involved only the carbon capture component, not the novel TRIG gasification coal plant that is in place at Kemper. The construction didn’t involve any new ways of converting coal to electricity, just CO2 capture. And Petra Nova was completed using 90% private capital, and in a competitive power market.
Why is Kemper important if new coal plants aren’t being built in the U.S. anymore?
Climate change doesn’t recognize national borders. It doesn’t matter whether the CO2 that warms the United States originated here or somewhere else. Kemper matters because its demonstration value is globally significant.
Across China, many plants gasify coal to make chemicals. They are different from Kemper’s gasifiers, but the plants use the similar carbon capture equipment as part of the process to make chemicals. Hundreds of millions of metric tons of highly pure CO2 is captured from these coal-to-chemicals plants, but it is vented directly into the atmosphere rather than stored. Kemper demonstrates the storage side of coal gasification. If the Chinese follow this lead, the CO2 emission reductions would be enormous.
Here in the United States, Kemper shows how to expand the existing U.S. CO2 pipeline network. Kemper extends the current Denbury Company pipeline system. Showing that this network is readily expandable demonstrates a pathway for future CO2 reductions from the power and industrial sectors. Together, these sectors account for over half the CO2 emitted in the United States.
A Final Thought
Carbon capture for the industrial sector has been commercially available for decades. This technology is now migrating to the power sector. But to be deployed rapidly, incentives are needed. Congress is considering measures that would accelerate the spread of carbon capture, which will ultimately reduce technology costs through learning and innovation. These include an extension and expansion of existing production tax credits that would raise the value of CO2 injected underground as well as tax policies that make financing capture equipment less expensive. We know these types of incentives work. Similar ones have helped drive renewables growth in the U.S. over the last two decades. Carbon capture technology is here. Now we need a push from Congress so it is widely deployed.