Low-carbon heat in the UK – is biomass heating a solution?

Published: Mon 24 Apr 2017
A blog entry by Matthew Myers

Contributed by:

Matthew Myers
Analyst
Delta Energy & Environment

Matthew Myers's Blog

Delta-ee’s recent study for the UK Government looking at the current and future costs of biomass wood pellets got me thinking about how biomass fares as a genuine low-carbon heating solution for the UK.

The UK Committee on Climate Change states, “Decarbonising space and water heating is one of the biggest challenges for carbon budgets” - currently only 2% of buildings derive heat from low-carbon sources. This number needs to be a lot higher if the UK is to achieve its overall ambitious carbon reduction targets, but which low-carbon technology is best? Is biomass a key part of the solution for low-carbon heating in the UK?

biomass

There’s much debate over the low-carbon credentials of biomass

Biomass heating is regarded as essentially net zero carbon, or close to carbon neutral, by many GHG accounting methods, including those developed by the UK Government. It is assumed that the carbon dioxide released when burning biomass is recaptured by the regrowth of new biomass elsewhere. As with all low-carbon technologies there is a caveat: the transport and processing of biomass is not zero carbon as oil-derived products are used to ship/transport and process the products produced. Therefore, we need to consider how far biomass fuel has been transported and the way it has been processed.

It is also important to consider where the biomass has been harvested from. Where biomass is sourced from well managed forests (in the case of woody biomass) that are habitually replanted (cfFSC), it can generally be considered low carbon at source. However, in other cases where indigenous forests are cut down to make way for more commercial biomass operations there is a change in land use, and a significant amount of carbon stored in the soil and other aspects of the forest can be released.

In Chatham House’s recent biomass report, they consider the transport, land-use changes and processing of woody biomass fuel to ultimately result in it having a greater carbon intensity than coal! A very bold assertion and clearly concerning if biomass fuels are to be considered low-carbon. A slightly older sustainability position paper published by a group of UK biomass fuel manufacturers is completely (and understandably) contradictory to the Chatham House findings as the conclusion of the report finds that, after taking into account carbon emissions associated with harvesting, processing and transport of the biomass fuel, the overall emissions are roughly one tenth that of traditional fossil fuel heating. While there may be certain conflicts of interest present in both the reports, the finding of the latter report that woody biomass is indeed lower carbon than fossil fuels is more in line with what I feel comfortable reporting.

Carbon emissions aside, it is also important to remember that the burning of biomass also results in the release of NOx and SOx gasses which contributes to poor air quality. The effect of burning woody biomass on air quality varies depending on the quality of the fuel used (e.g. how dry it is, its ash content etc.) and the type of boiler/stove used. Properly installed, modern domestic woody biomass boilers tend to be relatively clean burning in this regard, but still not as clean burning as standard gas boilers.

Things to keep in mind about your biomass

Is biomass heating really as bad as coal? Probably not. Is biomass heating completely carbon neutral? Definitely not. The reality is more complex, and we need to consider:

  • Where the biomass is sourced from, both in terms of transportation and land use.
  • How it is produced, making sure that the emissions associated with growth, harvesting and processing are minimised.
  • How much is available. There is a finite source of biomass and increasing volume may result in higher carbon sources and processes being exploited.
  • Where and how it is used. The finite supply means we should be using biomass in the most suitable locations, usually where other forms of low carbon heating are less practicable.  It should also be used in the most efficient technologies to get the maximum benefit.

There is no doubt that the UK needs to continue to rapidly decarbonise its heating. The UK Government currently envisages electrifying a large portion of the country’s heating demand (primarily using heat pumps) in order to drive this low-carbon agenda. While the long term supply of cheap natural gas is looking ever more uncertain there are concerns that the grid is currently unable to support a full transition to electric heating. Biomass boilers may be able to act as a low-carbon bridging solution.

Find out more

Delta-ee can help clients understand the wider low carbon heating markets and the role that biomass technologies and fuels can take in meeting our decarbonisation targets. We understand that achieving our long-term carbon goals will require a mix of technologies and fuels and can provide strategic advice on how new business models, services, and customer insight and analytics can be used to develop low-carbon heat strategies. 

In addition to the biomass heating study consultancy project completed by Delta-ee for the UK Government (more info to come at a later stage), Delta-ee offers its Heat Insight Service, providing insight across all UK heating technologies across the value chain. For further information, email Steven Ashurst or visit the Heat Insight Service web page.