Can fossil fuels ever be replaced by renewables?

Renewable energy sources will struggle to replace coal and gas-fired power stations as long as energy consumption continues to rise and fossil fuel subsidies remain in place, a new study has found.

Based on a study of electricity used in around 130 countries over the past 50 years, University of Oregon sociologist Richard York found that rising demand means it can require between four and 10 units of electricity produced from nuclear, hydropower, geothermal, wind, biomass or solar to displace a single unit of fossil fuel-generated electricity.

York's paper, published in the journal Nature Climate Change, recognises that many of these new technologies are yet to become fully established and have the potential to be more viable alternatives once they have matured.

But it also describes how creating more energy sources often leads to higher levels of consumption. Inventing more efficient car engines or houses opens up the possibility of building bigger engines and houses, the study says, which means total energy consumption often did not decrease significantly even with the rising efficiency of new technologies.

"One reason the results seem surprising is that we, as societies, tend to see demand as an exogenous thing that generates supply, but supply also generates demand," York said. "Generating electricity creates the potential to use that energy, so creating new energy technologies often leads to yet more energy consumption."

The paper concludes that simply building alternative sources of energy is not enough to get the world off the coal and gas hook. Instead, governments need to curtail the $409bn of subsidies the sector is estimated to receive each year as well as accelerate efforts to reduce the cost of clean alternatives.

"We need to be asking what political and economic factors are conducive to seeing real displacement," York said. "We need to be thinking about suppressing fossil fuel use rather than just coming up with alternatives alone."