Renewable energy trumps carbon capture

12 April 2019


Illustration of rising sea levels


Renewable energy combined with power storage offers a better pathway to tackle climate change than implementing carbon capturing technologies at fossil fuel plants, according to a new study.

The Intergovernmental Panel on Climate Change (IPCC) recently released a series of guidelines, called “energy transition pathways”, to prevent global warming from exceeding 1.5 degrees Celsius this century, which is considered the limit at which society will be able to continue to function as we know it.

In order to stay under this limit, the IPCC says we need to implement the pathways now and revolutionize our energy production methods by 2030.

All of the IPCCs pathways rely on the implementation of “carbon capture technology”, which absorbs carbon dioxide from fossil fuel power plants, to prevent it from interfering with the atmosphere, by separating it from the other gases released when fossil fuels are burnt. Consequently, there has been massive investment in these technologies.

But a new study questions if this is the right path.

“We actually compared different kinds of energy transition pathways from a technological perspective”, explains Denes Csala from Lancaster University, co-author of the study.

The study compared carbon capture and renewable energy like solar panels or wind turbines, combined with energy storage.

Implementing either technology requires an initial investment of energy, so the team investigated the “energy return on energy invested”, or “EROEI” for each scheme. As Csala explains, this provides a measure of “how good the resource is from an energetic perspective”.

The team compared EROEI numbers across different renewable energy technologies, with the data currently available on carbon capture technology.

“The best cases of carbon capture compare to the worst cases of renewable energy plus some form of energy storage”, reports Csala.

Given that the world’s total energy requirements are increasing, new power plants will need to be constructed, which will require some fraction of global energy resources.

The study argues that we are better off investing resources in renewables than in carbon capture at fossil fuel plants, as renewables offer a better “return on investment”.

Csala was quick to clarify that this comparison does not address the financial side of the technologies.

“There’s actually a lot of uncertainty involved with the economics”, explains Csala, given that the price of renewable energy technologies has decreased rapidly in the last few years, and carbon capture technologies are in their infancy.

In contrast, the energy efficiencies of the technologies are far more stable. Since this study attempts to compare strategies in the long term, they adopted the energetic comparison.

Importantly, this work focuses only on carbon capture from fossil fuel plants, and not “direct air capture” technologies. These are carbon capture devices which “scoop up” carbon dioxide that is already present in the atmosphere, reducing its impact. These technologies may still be critical to tackling climate change.

Csala hopes that in future this work can provide recommendations for specific countries.

“You can look at a certain country and look at the composition of its power plants, and then you can create very specific pathways...given the resources in the region, what are the technologies that you need to use in order to be sustainable and in order to have a society that is capable of coping with climate change.”


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