Biomass - Frequently asked questions
Biomass is organic matter. In the case of bioenergy, it typically refers to agricultural by-products and residues, woody waste products, and crops and microbes that can be used for fuel.
How is biomass used?
Biomass, in the form of compressed wood pellets, is a low-carbon replacement for coal that power stations can use to generate renewable energy. The UK, Japan and parts of Europe are already using biomass as a fuel to generate renewable electricity and heat.
What's sustainable biomass?
Sustainable biomass uses residues from the forestry industry such as sawdust and thinnings. Residues don’t have a negative impact upon forest growth, the amount of carbon being stored, biodiversity, and the socio-economic wellbeing of the communities close to the forests. When used for heat and power, sustainable biomass releases significantly less carbon dioxide than fossil fuels do.
Using forestry residues from harvesting also helps reduce the risk of forest fires, pests and disease outbreaks - particularly in areas where there's very little forest management.
How is burning wood sustainable?
Biomass comes from organic, living matter that is in a constant cycle of growth and renewal, absorbing carbon dioxide (CO2) from the atmosphere in the process. So when biomass is used to generate energy, the CO2 released is offset by the amount of CO2 the biomass absorbed from the atmosphere while growing as well as absorbing more CO2 from new growth.
Biomass is a very small part (just 4% in the US) of a broader forest products industry that includes the harvesting of wood for solid wood product sectors such as construction and furniture. The use of wood reduces the carbon impact in those industries, as well as locking away the carbon for longer.
How is shipping pellets around the world sustainable?
North America is a key supply region because of its well managed commercial forestry industry, commitment to sustainability and good infrastructure. The working forests in the US South alone are about three times the size of the UK and forest stocks have almost doubled since the 1950s.
The UK doesn't have sufficient forest capacity to meet demand and trucking pellets from Scotland to Drax Power Station would release more CO2 than shipping the pellets from the US South.
At Drax, we already have a low-carbon supply chain for our biomass and we're working with our partners to further decarbonise it. We report our supply chain emissions in our Annual Report, which is independently audited.
Does Drax cause carbon debt?
Drax only uses sustainable biomass from areas with managed forests that are stable or growing at a greater rate than they're being harvested. We source two thirds of our supply from areas in the US that meet these criteria.
As long as the annual forest harvest doesn’t exceed annual growth, switching from coal to woody biomass reduces atmospheric CO2 over timescales relevant to stabilising the climate.
In the US South, forest stocks have increased by a fifth over the past two decades and have almost doubled since the 1950s, according to analysis from the US Department of Agriculture.
In Europe, forest area has increased by 9% in the last 30 years and the volume of wood and carbon has increased by 50%, according to a report from Forest Europe.
Where do Drax pellets come from?
For the year ending 31 March 2021, we sourced our pellets from areas including USA (64.9%), Canada (15.5%), Latvia (9.3%), Estonia (2.8%), Brazil (2.5%), Portugal (2.4%), Belarus (1.4%)*, UK, (0.7%), Russia (1.2%)*, and other European countries (0.1%).
* Drax no longer sources biomass from Russia or Belarus, in line with international sanctions brought against Russia due to its war on Ukraine.
Are wood pellets sustainable long term without subsidies?
Yes, they are - we’re making good progress with our biomass strategy to increase our self-supply and reduce the costs of our biomass generation to £50/MWh by 2027. This will keep us on track to continue using biomass when subsidies end that year.
What kinds of feedstocks go into the wood pellets at Drax?
Drax uses processing residues, such as sawmill residues, where possible since they're relatively clean and dry and so well-suited to making into pellets. We also take residual material from harvesting operations, which are undertaken to supply multiple forest products (including for the construction and furniture-making industries). Only low-grade wood is used to create pellets. Such wood includes smaller or diseased or misshapen trees that have low commercial value and perhaps limited or no other available markets.
In some regions, such as British Columbia, the harvesting residues we use to make biomass pellets to generate renewable energy would otherwise be burnt on site. This helps reduce the risk of forest fires and pest and disease outbreaks.
As of 2021: Sawmill and other wood industry residue (38%), branches and tops (6.3%), thinnings (16.3%), low-grade roundwood (36.9%), agricultural residues (2.5%).
Doesn’t burning biomass produce more emissions than burning coal?
Unlike coal, sustainable biomass doesn’t add any new CO2 to the atmosphere. When sourced sustainability, biomass is in a constant cycle of renewal and carbon absorption across a landscape. When sustainable biomass is used to generate renewable electricity, it only releases the CO2 that was stored while the trees were growing before they were harvested. Because the biomass is sustainable, that CO2 is already being absorbed by other growing forests. Conversely, burning coal releases carbon that has been locked up for millions of years, increasing the amount of new carbon accumulated in the atmosphere.
How is bioenergy renewable?
Sustainable biomass is renewable because of the closed carbon cycle created when trees grow and take CO2 from the atmosphere. Whether the wood is used for bioenergy or these trees naturally decompose, the same amount of CO2 is released into the atmosphere.
The cycle remains in balance because the working forests that supply the low-grade wood used for biomass are replanted. These growing trees absorb more carbon.
The CO2 released when biomass is used to generate power is CO2 that was already in the biosphere and therefore isn't increasing the amount of carbon dioxide. This is different to fossil fuels, which release into the atmosphere CO2 that had previously been locked away underground for millions of years. That’s why fossil fuels contribute to climate change and sustainable biomass doesn't.
What certification does Drax use?
Our biomass complies with stringent standards set out in UK and EU law. UK energy regulator Ofgem audits Drax independently. Ofgem requires us to demonstrate that we use sustainably sourced biomass.
Our sustainable biomass sourcing policy goes beyond existing regulations and is led by science, best practice and transparency. We also engage with voluntary certification schemes and systems such as the Sustainable Biomass Program (SBP), Forest Stewardship Council (FSC), and Sustainable Forest Initiative (SFI).
How does Drax respond to critics of biomass?
Sustainable biomass helps to support healthy forest growth; in fact the forests where we operate are stable or growing, not shrinking. And all of this is supported by the United Nations Intergovernmental Panel on Climate Change, the world’s leading scientific body. Bioenergy with carbon capture and storage (BECCS) at Drax is critical because it's key to getting the UK off coal and tackling the global climate crisis.
While solar and wind will be essential in the new energy system, biomass is a reliable renewable energy source for when the sun doesn’t shine and the wind doesn’t blow.