The renewable heat incentive has now closed for new applicants. As a Government-led scheme to encourage the use of renewables, the scheme was a huge incentive and will continue to be for the next 20 years as accredited installations continue to receive payments from it. Or will they?

Chris Franklin, MD of Northampton-based Ranheat Engineering, looks into the matter …

Chris Franklin

The scheme has two regulators – OFGEM and the BSL, (Biomass Suppliers List). Both organisations are now carrying out audits to make sure you run legally in terms of local authority regulators (the Environment Agency and, in Scotland, SEPA).

Some of the regulations are relatively new, and some date back to the EPA in 1990. Yet the regulations are often not known about, and are not policed by the regulators due to time constraints. 

As the RHI has closed to new applicants, OFGEM and BSL have more time and are carrying out more audits than ever before. If they determine you don’t have the required permits and permissions, they are notifying the local authorities that an installation receiving Government funding is non-compliant, and withholding payments until they become compliant or can be struck off the scheme.

What is needed?

Guidance note PGN6/02, in its most recent form, came out in 2012 as a revision of 2004, and covers the manufacture of wood-based products. If you process more than 1000m3 of wood or wood-based products per year, you need this permit to operate legally.

Process means purchase – the exception is if you only saw wood, when the limit becomes 10,000m³ (sawmills only, generally). This guidance note has nothing to do with a wood combustion process. However, if you do have a wood combustion process (boiler/heater), it can be included on this permit for certain sizes of boilers and heaters.

What size of wood-fired boiler/heater needs a permit? 

The answer is all sizes – there is no cut-off point. Plants not capable of burning more than 50kg/hr need an exemption from the Environment Agency to burn waste as a fuel. You can apply online, and there is no charge – at the moment. 

Those processing over 50kg/hr but not capable of more than 90kg/hr will need a part B permit from Environmental Health. If you have a part B permit for your wood machining process, PGN6/02, the combustion equipment, can be added to the part B permit. 

If you don’t have the wood machining process permit, as you are below the 1000m³ limit, then you need a part B for a Small Waste Incineration Plant (SWIP) – these permits typically cost £1650 plus an annual maintenance fee.

The next band is boilers over 90kg/hr but less than 225kg/hr, under the Medium Combustion Plant Directive (MCPD). Companies will need a part B permit as detailed above, and will almost certainly be above the 1000m³ limit. If you go over the 225kg limit you will need an EA permit for the wood combustion process. You will still need a separate permit for your wood machining process. 

For an EA permit, you will have to apply to the EA for a price – they will quote individually, and it depends how much work they have to do, but can be between £3000-£16,000, depending on the location of your site.

So, what else is needed?

All chimneys serving an ‘industrial furnace’ need planning permission or written proof of permitted development. All chimneys will need chimney height approval and a written chimney height determination, submitted to Environmental Health. If there are any Sites of Special Scientific Interest (SSSI) within 2km, you can be asked for full computer modelling (caried out by SOCOTEC, current charge £3500 plus VAT).

All of the documents referred to can be downloaded from – and Ranheat Engineering offers free, confidential advice to new and existing customers around permitting regulations. 

01604 750005

Chris Franklin has been involved with the legislation since the mid-1980s and has worked closely with the various authors of the guidance notes. He has also sat on the board of directors of the Woodworking Machinery Suppliers Association since 2004.