As the government prepares to launch its Renewable Heat Incentive(RHI) for homeowners, new industry analysis has revealed most of the wood pellets burned for heating in Britain are already significantly exceeding the government's sustainability standards.

A new paper written by four of the UK's biggest biomass suppliers - CPL Renewables, Hoval, Land Energy and Verdo Renewables - analyses market data and shows that biomass can provide up to a 90 per cent reduction in carbon emissions compared to burning oil.

As a result, the group has predicted the government could heed calls from green groups to tighten up sustainability standards, and much of the industry would still be able to comply with the tougher rules.

The government is due to open the RHI for domestic properties this spring, and then from autumn, all biomass boilers will be required to meet a series of sustainability standards in order to qualify for the subsidy. These include proving that the biomass generator has 60 per cent lower greenhouse gas emissions compared to the EU fossil fuel heat average.

But the authors of the paper, which together provide nearly two-thirds of all the wood pellets burned for heating in the UK, calculate they already save 80 to 90 per cent in CO2 emissions compared to oil, well exceeding the government's sustainability targets.

The debate over the sustainability of biomass has become increasingly heated over recent years, with environmental NGOs and the renewable energy industry often at loggerheads over the level of carbon emissions associated with the technology.

Green groups such as Greenpeace, Friends of the Earth and RSPB have repeatedly argued the government's sustainability standards are too weak as they fail to account for emissions from trucks used for distribution of biomass fuel, emissions from indirect land use change, or the net reduction in the carbon stock caused by the removal of timber from forests.

But Tim Minett, chief executive of CPL, said he hoped the new industry paper would feed constructively into the debate, as it aims to take a more nuanced approach to the potential benefits and pitfalls of biomass. "It is natural for there to be a level of scrutiny about the relative impacts of any renewable technology, and biomass is no exception," he said. "As an industry we have responded to this by compiling real data from across the supply chain to show that the biomass actually produces relatively low levels of carbon compared to other technologies."

The report, which was written in conjunction with Ecuity Consulting, shows that transport can have a very low impact on overall emissions if the pellets are sourced locally to the plant or generator, and argues that the level of emissions savings from biomass power provides scope for any increase in emissions from indirect land use change to be accounted for. Indirect land use change or ILUC factors refer to the potential need to use additional land for timber or agriculture in order to replace the land used to provide biomass fuel.

As a result of the report's findings, the authors back green groups' calls for the government to conduct more analysis on the the indirect impacts of biomass on land use change. "A strong case has been made that changes in land use and alternative uses for biomass material can have an emissions impact and this has not been included within existing sustainability methodology," the report says. "The supporters of this paper agree that further analysis of the emissions from bioenergy is welcome and support DECC's work in investigating issues such as carbon debt and land use change. These factors may need to be taken into account in the future to ensure sustainability standards keep pace with scientific understanding."

Doug Parr, Greenpeace UK chief scientist, broadly welcomed the report as making a positive contribution to the debate. However, he added that it underlined the need for the Department of Energy and Climate Change (DECC) to publish its long-awaited biomass carbon calculator.

A draft version of the government's so-called "BEAC" calculator was presented by David Mackay, DECC's chief scientific adviser, this time last year. Unlike Ofgem's current carbon calculator, MacKay's method included the net reduction in the carbon stock caused by the removal of timber from forests, and the indirect emissions of burning biomass that would have been avoided if it had been used for other industries, such as construction.

His final methodology was supposed to be published last autumn, but has been significantly delayed. A DECC spokeswoman toldBusinessGreen that it was now intending to release the calculator "in the first half of this year".

Last week, the government confirmed that it had signed a contract with Gemserv to run the RHI's approved Biomass Suppliers List, supported by Hetas and Woodsure, and the final announcement on the launch of the domestic RHI scheme is expected in the coming months.

With an increasing number of firms seeking to take advantage of both the RHI and incentives offered to biomass through the Contracts for Difference mechanism, both green groups and many in the biomass industry will be hoping the government strengthens its sustainability standards sooner rather than later.