DRAX has defended its sustainable sourcing of biomass as the Government is urged to make sure subsidies are only paid to "genuinely" low-carbon biomass energy.

A new report from the Department of Energy and Climate Change has assessed woody biomass from North America for use in UK power stations, revealing that carbon emissions can vary significantly depending on how it is produced, with some biomass potentially producing more emissions than gas or even coal.

The calculations have sparking calls from environmentalists for the Government to rethink its policy of subsidies for the energy source.

At Selby-based Drax, where three generating units are being converted for burning biomass in place of coal, bosses say sustainability had always been "absolutely central" to its strategy.

Dorothy Thompson, chief executive of Drax, said: "The academic study by DECC confirms what Drax has always argued, that there is a right way to source biomass and a wrong way.

"We welcome that it confirms the fact that where biomass is sourced sustainably major carbon savings can be delivered.

"When we complete our plans to convert three of our generating units to burn sustainable biomass in place of coal we will be able to deliver cost effective, renewable electricity to the equivalent of over three million homes and reduce our carbon emissions by over ten million tonnes a year.

"No other renewable can make such an impact and provide electricity at scale day-in, day-out whatever the weather."