According to a new study reported in Nature Energy, wind turbines and solar panels combined with energy storage provide a better hope for addressing climate change than attempting to capture carbon from fossil fuel power stations.
Carbon capture technologies—which are new, or still undeveloped, technologies that acquire CO2 emissions from coal- and gas-fired power stations—have an important role to play within the models that serve as the foundation of international agreements to address climate change, such as the Paris Climate Change Agreement of 2015.
However, a new study reveals that resources that would be exploited to build and set up carbon capture technologies would be better invested in developing more wind turbines and solar panels and concentrating on advancing energy storage options to promote these instead.
An international research group with researchers from Lancaster University, Khalifa University, Clemson University, UiT The Arctic University, and the University of Florence has estimated the energy output after considering the energy required to develop and operate the system for carbon capture technologies across a variety of fossil fuel power stations, including natural gas and coal.
These outcomes were compared with the energy return on energy invested for renewable energy systems, like solar panels and wind farms, coupled with different types of energy storage systems, like hydrogen or pumped hydro-power and batteries, and found that even worst cases of renewables, with storage, produced comparable results with the best instances of carbon capture.
The scientists estimate that this is partly because of the net energy losses from executing carbon capture, which involves penalties caused by the energy required to create and then run the carbon capture and storage processes. Furthermore, energy is required to manufacture tools—like pipes and compressors essential to capture and store carbon—which is called embodied energy.
All these lead to a decreased net energy output from power stations with carbon capture.
The energy return on energy spent for solar panels and wind turbines is dependent on the energy costs to develop the panels and turbines themselves, as well as on how sunny or windy the area is where they are set up.
However, even fairly efficient renewable sites offer a better energy return when compared to most of the carbon capture technologies.
It is more valuable, energetically, to invest the available energy resources directly into building new renewable energy and storage capacity rather than building new fossil-fuel power stations with carbon capture. The better net energy return of investing in renewable energy makes it more likely to meet emission targets without risking a reduction in energy availability, due to dwindling fossil fuel supplies and a climate-constrained emissions budget. Given its net energy disadvantages, carbon capture and storage should be considered a niche and supplementary contributor to the energy system, rather than be seen as a critical technology option as current climate agreements view it.
Dr Denes Csala, Study Co-Author and Lecturer in Energy Storage and System Dynamics, Department of Engineering, Lancaster University
The study is the first in the world to compare these technologies using net energy analysis and it is summarized in the paper titled “Comparative net energy analysis of renewable electricity and carbon capture and storage,” published in Nature Energy.
The authors of the study include Sgouris Sgouridis of Masdar Institute, Khalifa University; Michael Carbajales-Dale of Clemson University; Denes Csala of Lancaster University; Matteo Chiesa of UiT The Arctic University of Norway; and Ugo Bardi of the University of Florence.