Climate Changed

Fossil Fuels Are Far Less Efficient Than Previously Thought

As oil, coal and gas get harder to extract, renewables are closing the gap.

Photographer: Vincent Mundy/Bloomberg
Lock
This article is for subscribers only.

Fossil fuels, long regarded for their high-energy return on investment, are not as efficient as once thought. In fact, their final yields are not much better than those of renewable options, according to a new study.

Oil, coal and natural gas have generally returned energy at a ratio of 25:1, meaning that for every barrel of oil used in production, 25 barrels have been made. But that measurement, called energy return on investment (EROI), has traditionally been taken when fossil fuels are removed from the ground, and fails to account for energy used during the refining process.