To meet its emissions targets, Southern Co. said this month it is considering another carbon capture project in Kemper County, Miss. — the site of one of the most expensive cancellations of an initiative to create a near carbon-free coal plant. The Department of Energy-funded project will determine whether it is feasible to store carbon dioxide from three of Southern’s power plants in Alabama and Mississippi, including Plant Ratcliffe, a natural gas plant that was originally designed to gasify lignite coal and store the majority of its CO2 emissions. That power plant was known as “Kemper” for much of its construction life until delays and cost increases prompted Mississippi utility regulators to say the facility could run on natural gas only.
The move by Southern mirrors efforts by other utilities that are taking a renewed look at carbon capture and storage (CCS) as a way to meet recently-announced carbon emission targets from 2030 to 2050.
But while some utilities have seriously considered the technology more than others, it’s unclear whether efforts can be turned into working projects anytime soon — and whether company carbon targets may be unreachable as a result. That is so even though electric companies are relying on natural gas more as they transition away from coal and tap backup for renewable power.
Natural gas has less carbon than coal, but it’s not emissions-free. Getting it there is “the biggest issue to solve,” said Tom Fallgren, vice president of generation for Public Service Co. of New Mexico (PNM). PNM has a goal to have 100% carbon-free power by the end of 2040.
“I think we understand a significant part of that road map, but we don’t understand the last 20% of that road map at the moment,” said Fallgren in an interview last week. The key with carbon targets is striking a balance between maintaining a reliable system in an economic way for customers, he said. For PNM, that may be carbon capture, replacing natural gas with hydrogen or methane capture. All have potential but either are costly or haven’t been tested at scale.
Rich Powell, executive director of conservative nonprofit ClearPath, said utilities broadly are looking at carbon capture because renewable energy can only get them so far in achieving net-zero targets. Also, many utilities already have existing fossil fuel infrastructure, and retrofits could be easier than tearing units down and building something new. There’s also a “pretty significant incentive” for carbon capture, he said, through federal tax credits for carbon storage under 45Q of the tax code. The Treasury Department issued a long-awaited proposed rule on 45Q implementation last month.
“There’s now more certainty amongst investors that there’s a path forward that the utilities can use for that,” Powell said.
Yet how large of a role carbon capture will play in reaching utility net-zero emissions carbon goals is something that remains to be seen, according to Mahmoud Abouelnaga, a solutions fellow at the Center for Climate and Energy Solutions (C2ES). To what degree utilities consider CCS on gas depends on the makeup of their portfolios and if the technology’s price comes down enough to spur more retrofits, Abouelnaga said. Some utilities — like in Texas or the Midwest — also have better renewable resources like wind at their disposal than Mid-Atlantic states or those in the South, C2ES said. Until storage capability increases to a sufficient degree, natural gas plants will be around as a backup, or “buffer,” to renewables, Abouelnaga added.
John Thompson, technology and markets director at the Clean Air Task Force (CATF), said while it’s important that CCS is a part of Southern’s strategy — particularly on gas and biomass — utilities generally need more incentives if they’re to become early adopters of the technology.
“I think the challenge as companies make these pledges, including Southern, is how do we structure incentives at a federal level to encourage them to be a first mover, as opposed to waiting,” Thompson said, referring to utilities’ various emissions targets. Incentives could include funding for demonstration projects, federal grant money or operating support in the form of a production tax credit (PTC), Thompson said.
“Utilities should have a choice of either using 45Q or using a PTC for a specific plant,” he said, adding that a PTC will “probably work better” for a standard, baseload gas plant with CCS.
What’s the Kemper plan?
There are two current large-scale carbon capture projects on fossil fuel plants globally, including NRG Energy Inc.’s Petra Nova project on a coal plant in Texas. According to the Global CCS Institute, there are at least three large U.S. power generation projects in “advanced development,” including Project Tundra, a proposal led by Minnkota Power Cooperative to build a carbon capture project on a coal generator in North Dakota. However, the formal blueprints fall short of what some analysts say will be needed to keep rising temperatures in check and curb emissions from natural gas plants as utilities move closer to their 2030 and 2050 pledges. In the meantime, many utilities say they are considering CCS technology, even if there’s not advanced construction occurring.
For example, Arizona Public Service Co., which is owned by Pinnacle West Capital Corp., has a target of providing 45% renewable power by 2030 and delivering all carbon-free power by 2050. The electric company is evaluating carbon capture technologies, but they are not a part of any plans right now, said Jim McDonald, a company spokesman.
The Southern Co. project in Kemper County is being spearheaded by the Southern States Energy Board and will support a $23.5 million feasibility study. “This is really a study to assess the feasibility … what it would take to get the permits for it, what it would cost,” said Jeff Burleson, Southern’s environmental and system planning vice president, in an interview with E&E News last week.
Southern’s coal-fired power plants Miller in Alabama and Daniel in Mississippi will be included in the plan as well as Plant Ratcliffe.
Southern said it chose Kemper County for the study because of geology that may be able to store “hundreds of millions” of metric tons of carbon underground, Burleson said. The geologic formations known as salt domes are considered to be great places to store carbon because they can trap the gas and prevent it from coming back out of the ground, he said.