What is our assessment?

Using CCS on fossil-fueled power plants will reduce electricity production emissions, but it is more expensive, more energy-intensive, and more polluting than readily available, cheaper, and cleaner alternatives like wind, solar, and geothermal. Based on this, and the risk that large-scale deployment of CCS on fossil-fueled power plants could drive continued production and use of coal and gas, we conclude that using CCS on fossil fuel power plants is “Not Recommended” as a climate solution.

What is it?

Carbon capture and storage (CCS) is a technology that reduces GHG emissions from fossil fuel-powered electricity generation facilities by selectively capturing CO₂ from the power plant’s exhaust flue, preventing it from entering the atmosphere. The captured CO₂ is then concentrated, compressed, and permanently stored underground. There are other commercially available CCS technologies, such as pre-combustion capture and oxy-fuel combustion, but these are used almost exclusively for industrial processes like gas processing and cannot be readily retrofitted to existing power plants. CCS can also be applied to capture CO₂ from other industrial facilities that generate emissions from fuel combustion or production processes, like cement or ethanol production plants, or from biomass energy power plants. Instead of permanent storage, captured CO₂ can also be used as a chemical precursor for the manufacture of other products or for enhanced oil recovery, but, compared to geologic storage, these post-capture uses of CO₂ emit GHGs, thereby reducing or eliminating the emissions reduction efficacy of CCS. 

Does it work?

The technology and chemistry for the selective capture of CO₂ from the exhaust of a power plant are effective. There are numerous chemical, membrane, and cryogenic methods for capturing CO₂, but monoethanolamine (MEA) is the predominant commercially available chemical absorbent currently in use in power plants with CCS. CO₂ capture efficiency varies with the type of reactive absorbent material and plant operations. Most CCS installations target 90% CO₂ capture rates, although actual capture rates are usually lower. CCS infrastructure is large, and the process of capturing CO₂ from power plant exhaust is complex, expensive, and energy-intensive. CCS requires the flue gas to be pumped to different parts of the power plant, the CO₂ to be captured and then separated from the sorbent material, and the concentrated CO₂ to be compressed for transport and storage. Energy for all these processes comes from the power plant. Various studies estimate CCS consumes at least 15–25% of the plant’s total generation capacity, with most of the energy used to separate the CO₂ and regenerate the sorbent material. 

CCS has been used in pilot studies and commercial operations in a few dozen coal and natural gas power plants since the late 1990s. Despite the functional effectiveness of the technology, use of CCS to reduce power plant emissions has not been broadly adopted, and most CCS projects initiated in the past three decades have failed or been discontinued. Based on various assessments and projections, deployment of CCS on power plants has consistently lagged behind its expected contribution to emissions reduction. There are currently only four power plants with CCS in operation in the world, less than 0.05% of the global fossil fuel power plant fleet. According to a 2021 study, only 10% of proposed CCS projects for power plants have actually been implemented. Based on another study, 78% of all power plant and industrial manufacturing CCS pilot and demonstration plants with a project size greater than 0.3 Mt CO₂ /yr have been cancelled or put on hold. 

Why are we excited?

Globally, emissions from coal- and gas-fired power plants are still increasing, primarily in China and India, where large numbers of new thermal power plants have been built in the last two decades. Given the typical 30- to 45-year operational lifespan for coal and gas power plants, retrofitting these newer plants with CCS could substantially reduce their operational emissions while also allowing plant owners and investors to recover their investments. Installation of CCS to reduce emissions can also be prioritized for power plants located near places with geologic storage and where alternative electricity generation options are limited. There is a large amount of active research underway to develop and test alternative carbon capture technologies, most aimed at increasing carbon capture efficiencies and reducing energy demands and costs. Other research on the factors contributing to the failure of most CCS projects to date may lead to the development of regulations and policies that require or incentivize the use of CCS for power plants, which could increase the current low implementation and success rates for this emissions reduction technology. 

Why are we concerned? 

While CCS can reduce the operational CO₂ emissions from fossil-fueled power plants, large-scale deployment of this technology will likely drive continued production and use of coal and gas. Even before fossil fuels are burned, extraction, transport, and processing generate substantial GHG emissions, particularly for gas. Therefore, in addition to perpetuating the fossil fuel industry, even 90% efficient CCS reduces only a fraction of the life cycle emissions from coal and gas. 

Widespread deployment of CCS in the electricity sector could also delay or crowd out deployment of wind, solar, and geothermal energy, slowing the clean energy transition that is already underway. Beyond these risks, the three-decade-long failure of power plant CCS to make the transition from pilot-scale science and technology to large-scale commercial deployment reflects its systemic problems and limitations. Unlike wind and solar energy, which have seen costs decline rapidly with development and deployment, CCS on power plants shows little evidence of a learning curve. It remains very expensive and very energy-intensive. A large-scale CCS demonstration project can cost more than US$1 billion to build and, in addition to its operational costs, CCS consumes at least 15–25% of the energy that the plant could otherwise sell to customers. CCS-related energy requirements could mean that a power company would need to build an additional power plant to compensate for reduced electricity deliveries from every four of its power plants equipped with CCS. 

Due to these high project risks and costs, as well as the lack of regulations and policies to require or support CCS on power plants, public and private investments in the technology have been falling. Despite all this, recent research shows that the vast majority of lobbying spending for government support of CCS comes from fossil fuel interests, which have publicly stated that they view the technology as a strategy to extend society’s use of fossil fuels. Finally, in contrast to most other climate solutions that provide other benefits to natural systems or human well-being, CCS on power plants does nothing to address or alleviate the current harm from toxic air pollution produced by fossil-fueled power plants.