Growing crops for fuel as opposed to refining fossil fuels and substituting bioethanol for gasoline is a sustainable energy strategy, Japanese researchers say.

In a study published in the International Journal of Foresight and Innovation Policy, researchers analyzed the overall life-cycle impact on raising fuel crops and the energy required to process and exploit biomass compared with fossil fuels.

The researchers from Japan's National Agriculture and Food Research Organization said they wanted to assess the potential of biomass utilization while taking into account the cumulative fossil energy demand and climate change impact.

Biomass derived from sugarcane, sugar beet and other crops has emerged as one of the most promising renewable energy sources, they said.

The substitution of gasoline with bioethanol converted from energy crops has considerable potential for rendering society more sustainable, they found.

"We proved that the improvement in cultivation technologies and the establishment of regional biomass utilization systems have large potential for saving fossil fuel resources and reducing greenhouse gas emissions," the researchers said.