(Image: The natural gas life cycle is just one factor cited by researchers who cast doubt on the efficacy of carbon capture at energy facilities.)
Carbon capture has been touted as an effective way to reduce emissions on a global scale, and that has attracted the eye of investors looking for innovative opportunities to boost their green cred. However, the proof is in the pudding. Evidence is mounting that carbon capture is becoming irrelevant—and may even do more harm than good—when renewable energy is already at hand.
Not too long ago, carbon capture was actually a pretty sensible solution for emissions from power plants, at least from an economic perspective. Renewable energy was expensive, and the global fleet of coal power plants seemed to be on a path of all but certain growth.
More recently, low-cost wind and solar have combined with energy storage, energy efficiency, and smart-grid technology to beat coal at its own game.
Here in the U.S., coal power plants are already falling like dominoes. Low-cost renewables are also beginning to threaten coal’s main competitor, natural gas.
In addition, the clean tech supply chain, workforce, and financial pipeline are all growing and maturing. That has created the conditions for the renewable energy transition to accelerate.
Into this scenario steps new research from Mark Z. Jacobson, professor of civil and environmental engineering at Stanford University.
Published this month in the journal Energy and Environmental Science, of the Royal Society of Chemistry, Jacobson’s study looks at the publicly disclosed emissions from a coal power plant equipped with a carbon capture system. The study also covers public data from a plant that captures carbon from the ambient air.
At both of the plants, the carbon capture systems were run on electricity, generated by natural gas.
That should set off red flags right there. Gas produces less pollution when burned than coal, but the burning comes at the tail end of a long “upstream” chain of methane emissions.
Methane is the primary component of natural gas, and it is a powerful greenhouse gas. Methane escapes from multiple points in the supply chain, including drilling operations at natural gas fields, transportation pipelines, storage facilities and distribution networks.
That is exactly what Jacobson takes into account. His study compares the savings in carbon emissions at both plants with the upstream emissions related to natural gas supply, as well as “downstream” emissions from the coal power plant and emissions relating to gas-sourced electricity.
The results are striking. According to Stanford, typical studies of carbon capture technology are based only on downstream emissions. By including upstream emissions, Jacobson arrived at a 20-year average carbon capture rate of approximately 10 percent.
That’s a far cry from the impressive rate of 85 to 90 percent claimed by carbon capture stakeholders.
Jacobson’s study also took social costs into consideration, including “air pollution, potential health problems, economic costs and overall contributions to climate change.”
These upstream impacts are critical, but until now they have played little part in the carbon capture economy.
“Even if you have 100 percent capture from the capture equipment, it is still worse, from a social cost perspective, than replacing a coal or gas plant with a wind farm because carbon capture never reduces air pollution and always has a capture equipment cost,” Jacobson argues.
Of course, carbon capture, biogas recovery and other air pollution controls will continue to play a growing role in reducing greenhouse gas emissions from other industrial operations, including agriculture.
For now, though, carbon capture for electricity generation is a no go, at least here in the U.S.
The U.S. Department of Energy is still funding carbon capture research. However, the agency’s lone showcase carbon capture project, the $1 billion FutureGen facility, stalled out back in 2015 and is permanently mothballed.
It appears that U.S. policymakers have already looked at the same math as Jacobson and reached a similar conclusion.
Image credit: Pixabay
Tina writes frequently for TriplePundit and other websites, with a focus on military, government and corporate sustainability, clean tech research and emerging energy technologies. She is a former Deputy Director of Public Affairs of the New York City Department of Environmental Protection, and author of books and articles on recycling and other conservation themes. She is currently Deputy Director of Public Information for the County of Union, New Jersey. Views expressed here are her own and do not necessarily reflect agency policy.