The government has been challenged by auditors to prove the UK’s controversial biomass industry meets sustainability rules. Biomass involves burning wood or plants to create heat, electricity or transport fuel, and the industry receives hundreds of millions of pounds in annual government support. But the National Audit Office (NAO) has now said the government “cannot demonstrate” that biomass companies are complying with sustainability rules, because it is not measuring them properly. …It comes as the government considers extending financial support for the industry, which its climate advisers have warned does not provide good value for money. However, the Climate Change Committee (CCC) also agrees that biomass will help the UK economy move away from fossil fuels. …The energy security department last summer committed to tightening up its sustainability rules. …Investment analysts at Barclays said there were “no surprises” in the NAO’s findings that “high standards are required for further support”.