The next step

To further information on RHI changes

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To the Biomass Suppliers List

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Chatham House report

[Document]

Biomass boilers - are they green?

Hot stuff

Biomass boilers burn wood pellets, chips or logs to power central heating and hot water systems. They’ve been popular because of the financial benefits available through the Renewable Heat Incentive (RHI) - this payment is based on the type of biomass technology you install, how much energy your boiler can produce and how much energy you actually use.

Note. The non-domestic RHI changed on 1 April 2017. The main difference is that the previous approach, which saw alternative payment rates applied to different boiler sizes, has been replaced with a single payment structure across all boiler sizes (see The next step ).

Green points

The financial incentives to buy a biomass boiler are based on the fact that it’s a renewable and carbon-neutral alternative to one that uses fossil fuels. It’s also one of the lowest cost solutions in terms of carbon savings. Indeed, in order to qualify for the RHI, you have to use fuels that meet the government’s sustainability criteria.

Tip. To comply you need to buy fuel from a trader registered on the Biomass Suppliers List (see The next step ). This means the pellets meet certain greenhouse gas savings compared with fossil fuels.

There’s a problem

A report published in February 2017 claims that promoting wood as a renewable energy source is a misnomer. The study, carried out by think-tank Chatham House, uses data from the Intergovernmental Panel on Climate Change to show that wood emits more CO₂ per unit of energy than coal and almost double that of natural gas (see The next step ). The experts argue that the accounting systems used to ensure that biomass is carbon neutral are too simplistic.

Carbon (mis)counting

The current regulations don’t count the emissions from burning wood at all - the assumption is that this is balanced by the planting of new trees. But the Chatham House report highlights that the overall emissions from burning trees will depend on a variety of factors, including: (1) the type of wood used; (2) what would have happened to it if it had not been burnt for energy; and (3) what happens to the forest from which it was sourced.

The alternatives

The experts suggest that only residues which would otherwise have been burnt as waste or would have been left in the forest and decayed rapidly can be considered carbon neutral. They also suggest that feedstock should come from sawmills and post-consumer waste.

Tip. Working out the environmental pros and cons of different sources of biomass is extremely complicated and the debate is likely to go on for some time yet. However, if you have a biomass boiler then so long as you keep using registered traders to supply the feedstock you’ll satisfy the requirements of the RHI etc.

For links to further information on RHI changes, to the Biomass Suppliers List and to the Chatham House report, visit http://tipsandadvice-environment.co.uk/download (EN 11.10.07).