HETAS is alerting installers and specifiers to changes in air quality regulations, which affect biomass applications for the non-domestic Renewable Heat Incentive.

From 24 September 2013, applications for a biomass boiler will need to have either a RHI emission certificate or an environmental permit demonstrating low particulate and nitrous oxide (NOx) emissions. Since the non-domestic RHI was launched in 2011, the majority of funding has been allocated to biomass installations, with commercial users reaping the benefits of using biomass as a low-carbon fuel.

The criteria for the RHI emission certificate is a maximum of 30g/GJ net heat input for particulate matter, and 150g/GJ for NOx (expressed as NO2). If the biomass boiler does not have a RHI emission certificate, then an environmental permit from the Environment Agency is required. Biomass boilers that do not have a RHI emission certificate or an environmental permit will be ineligible for the non-domestic RHI.

Additionally, end users must make sure they use the correct fuel as specified in the emission certificate. Fuel quality is paramount, and moisture content has the biggest effect on heat output as any water in the fuel has to evaporate away before the wood or biomass will burn, using up energy and reducing the amount of useful heat as opposed to steam up the chimney. For installations using wood pellets, the European ENplus standard ensures fuel quality with minimum standards for ash content, ash melting temperature, wood pellet size, dust, moisture content and heat output.

HETAS is approved as the UK certification body for ENplus by the European Pellet Council (EPC), and is able to certificate both producers and traders under the ENplus scheme.