Scientists provide another reason to bid adieu to coal

Energy derived from fossil fuels is far less efficient than previously thought, according to a new study published in Nature Energy. And even though new renewables are already cheaper than coal, rising costs and vanishing subsidies can make the gap in prices widen.

Based on the energy return on investment (EROI) score, researchers for the University of Leeds compared the production of energy to the energy used to extract it. In practice, an EROI of 10:1 means that society will be able to use 90% of the energy extracted. According to previous estimates, the EROI for renewables rarely came out at over 15:1, while fossil fuel energy often surpassed 25:1. 

The studies providing those estimates usually considered only energy extraction without looking at further stages. However, energy is also needed for creating infrastructure, transport, and conversion of extracted energy into a useful form, which previous studies rarely addressed. Thus, the group decided to reconsider those calculations.

Based on 16 years of open data from the International Energy Agency and Exiobase, an extended analysis showed fossil fuels’ EROI to be 6:1, which is equal to solar. Meanwhile, the EROI of fossil fuels drops to just 3:1 if they are used for producing electricity, making them only half as efficient as renewables. 

Researchers are quite sure that as fossil fuels get depleted, the ratio is going to decline further, with the need for new infrastructure investments. This also means that further reliance on fossil fuels may lead to lower energy supplies and rising prices. The results will be grave for the global economy. The findings further underline the need for sustainable energy in future. 

Marco Raugei from Oxford Brookes University notes the “sobering nature” of the study’s results, bearing significant insights for real-world policies. “This study really gives the green light for even faster decarbonization by moving to renewables,” Paul Brockway, a co-author of the study, observes. 

Renewables are on the rise globally. The question remains, however, whether the transition will be fast enough to secure a livable climate in decades to come.