A carbon capture proposal for a central Louisiana power plant has been dubbed “Project Diamond Vault” by its owner, Louisiana utility Cleco. The utility says the project will have “precious value” to the company, customers and the state.
Yet less than six months after announcing plans to capture carbon from plant emissions and store them underground near the plant, Cleco revealed in a recent filing to its state regulator that the retrofit of carbon capture of $900 million could reduce electricity generated for its customers by around 30%.
Cleco maintains that he did not go down this path. But, if it decides to generate the extra electricity needed to run the carbon capture process, it could increase the plant’s water consumption by around 55%, according to studies of similar power plants.
The Louisiana project is no exception.
Harnessing enough carbon to bring the climate crisis under control would double humanity’s water consumption, according to researchers at the University of California, Berkeley. Whichever method is used – at a power plant or by capturing the carbon directly from the air – more power and more water will be needed.
Cleco’s proposal provides an object lesson in how one solution can exacerbate another problem.

“These technologies for mitigating climate change have unintended environmental impacts, like water use and water scarcity,” said Lorenzo Rosa, senior fellow at the Carnegie Institution for Science at Stanford. Carbon capture and sequestration increases water withdrawals from power plants between 25% and 200%, according to a report by the Intergovernmental Panel on Climate Change that cites Rosa’s work.
The same IPCC report says carbon capture could help reduce the fossil fuel pollution that is warming the planet’s climate and causing more extreme weather.
The power-generating unit that Cleco plans to add carbon capture technology to – the Madison 3 unit – generates electricity by burning 70% petroleum coke, a byproduct of petroleum refining , and 30% charcoal. It has been estimated that retrofitting a coal-fired power plant with carbon capture technology could increase that plant’s water consumption by 55%. A similar increase could be expected for retrofitting a petroleum coke-fired power plant, Rosa said.

Cleco, however, told Floodlight that it cannot say for sure how much energy and electricity the carbon capture process will use until the initial designs and studies are complete in 2024. Cleco engages in research and engineering at the highest level and cannot speculate on the outcome of the study,” the company said in an email response.
The carbon capture technology proposed for the plant chemically removes carbon from exhaust gases from facilities burning fossil fuels. Cleco expects the operation of the carbon capture equipment to consume 200 megawatts of electricity, according to a recent Louisiana Public Service Commission filing. That’s about a third of the power plant’s current capacity of 641 megawatts.
The industry says retrofitting some fossil-fuel power plants is cheaper than shutting down facilities and building renewables. To offset the cost of the technology, companies can use the carbon to squeeze more oil out of aging oilfields.

Adding technology to power plants is expensive. Wyoming, which produces 40% of the country’s coal, passed a law requiring electric utilities to generate some of their electricity from coal-fired power plants with carbon capture. So far, this has proven unfeasible, as power companies have warned that the technology will likely increase water consumption and could increase residential electricity bills by up to $100 per month. A study by Energy Innovation: Policy and Technology found that coal-fired power plants equipped with carbon capture technology were three times more expensive than wind power and twice as expensive as solar power.
Despite the problems, the push for carbon capture in the state is growing. Louisiana Governor John Bel Edwards, a Democrat, praised the Cleco project, saying when announcing the Diamond Vault project that it and similar projects aimed at reducing energy-based climate pollution are essential to the state.
More than a dozen carbon capture projects have been proposed in Louisiana as lawmakers and industry leaders tout carbon capture as a solution to the state’s industrial carbon emissions. Louisiana is one of the nation’s top carbon dioxide emitters, and the Diamond Vault project is the only carbon capture proposal for a power plant in the state. The other proposals concern other industrial processes or carbon storage.
Last year’s bipartisan Infrastructure Act allocated $12 billion in federal funding for carbon capture and storage technologies, and August’s Cut Inflation Act creates tax breaks for power plants electricity and industrial facilities that pursue carbon capture and storage (CCS). Federal support for the technology is essential: No utility-scale power plant in the United States currently uses CCS, largely because it is expensive, according to the Congressional Research Service.
The need for additional water for carbon capture would strain drier parts of the country. But even in Louisiana, which receives more rain on average than any other of the contiguous 48 states, additional water use could be problematic. It has no statewide water management plan and in some areas groundwater is being sucked up faster than it can be replenished. Electricity generation is by far the largest user of fresh water.
“To think that this water is available is a mistake,” Mark Davis, director of the Tulane Institute on Water Resources Law and Policy, said of the water needed for CCS. “It’s a mistake that can be avoided.”
Cleco has three power-generating units that pump up to 700,000 combined gallons of water per minute from adjacent Rodemacher Lake to cool equipment, according to 2021 data from the U.S. Energy Information Administration. In 2015, electricity generation accounted for about 98 percent of surface water withdrawals in Rapides Parish, home of Cleco’s Rodemacher Generating Station, according to the city’s latest five-year water use report. ‘State.
Water policy experts have previously raised concerns about the lack of a statewide management plan in Louisiana, most recently when fracking for natural gas and oil became commonplace. in the state. The growth of hydraulic fracturing, which uses millions of gallons of water, in northwest Louisiana prompted lawmakers to pass a voluntary surface water management program in 2010.
Earlier this year, Sen. Robert Mills, a Republican lawmaker from northern Louisiana, introduced a bill to make agreements mandatory, which would have required companies to pay for the water they take from rivers and lakes. Oil and gas lobbyists blocked the proposal, Mills said.
“We gave water the whole time,” Mills said. “The state constitution says you can’t give away anything of value.”
The bill died in committee, without any legislator deciding to move it forward.
“We have plenty of water today,” Mills said. “But what about tomorrow?”
This story also appeared in the Louisiana Illuminator and The Lens.
This story is supported by a grant from the Environmental Journalism Fund.