How biomass is helping us along the way to a zero-carbon future
6th March 2020
Renewable power sources have proliferated in the last decade, helping the UK to transition to a cleaner, greener energy future. However, this has also caused some instability on the electricity grid, as wind and solar power can be intermittent.
The power network is finely balanced, and biomass helps bring security back to the grid by stabilising the system and creating room for even more renewable sources. In the UK alone, biomass accounts for around 31% of renewable power generation.
Read on to learn more about biomass, the underrated renewable power source that’s helping to power homes, businesses and other organisations across the UK.
Biomass: the basics
Biomass is organic matter such as wood or plant materials. It’s used for power generation and as an alternative source of heating in industry and even homes. Biomass is used in the same way as coal, but with much lower associated carbon emissions.
As the largest provider of renewable electricity in the UK, Drax uses low carbon biomass to help the grid to flexibly meet electricity demand alongside other sources. These can be weather-dependent or ‘intermittent’ renewable sources, such as wind and solar, as well as other more established technologies such as nuclear, hydro and gas.
Understanding where biomass comes from
It’s possible to produce biomass from different feedstocks (or materials) including agricultural or forestry residues, waste such as farming by-products or uneaten food, or dedicated energy crops.
The type of biomass we use at Drax Power Station is high-density, compressed wood pellets.
We source these pellets from responsibly managed working forests in the US, Canada, Europe and Brazil. Mostly, the pellets comprise low-grade wood that’s a by-product of producing and processing higher value solid wood products (such as saw-timber for construction and furniture).
We use scientific evidence to inform the type of wood we source, so we can maximise the positive carbon contribution that sustainable biomass can deliver. This helps to protect and improve the forest ecosystem.
We ship the wood pellets to the UK for use at our power station near Selby in North Yorkshire. We report on the carbon emissions from our biomass supply chain, including forestry, manufacturing and transportation, to the energy regulator, Ofgem. Overall, generating power with biomass at Drax reduces carbon by more than 80% compared to coal and more than 60% compared to gas.
How can we be sure biomass is sustainable?
Biomass producers and users must meet a range of stringent measures for their biomass to be certified as a sustainable and responsibly sourced. Thanks to these robust measures, biomass is a cleaner and more sustainable option than fossil fuels.
To ensure our biomass reduces emissions in the most effective way possible, we commit to maximising carbon benefits through a range of measures. These include using:
- Only responsibly sourced sawmill residues
- Forest residues from regions with high rates of decay or where it’s possible to extract this material to the roadsides as part of standard harvesting practices
- Thinnings that improve the growth, quality, or biodiversity values of forests
When using roundwood, Drax sources only low-grade by-products that can’t be used for saw-timber products. Our aim is to help maintain or improve the growing stock, growth rate and productivity of forests. This helps improve the health or quality of forests too, by using damaged wood that’s unusable by the saw-timber industry.
We’re also committed to not using biomass where it adversely affects the long-term potential of forests to store and sequester carbon. Or where doing so would displace solid wood product markets or push beyond the sustainable capacity of the forest. We also don’t use biomass that comes from tree stumps.
There’s scientific consensus, including the UN’s climate change body, the Intergovernmental Panel on Climate Change (IPCC on a key point. They agree that the carbon emitted by biomass power generation is cancelled out by the increased rate of carbon uptake in the working forests where trees flourish. where trees continue to flourish.
This means biomass power generation is carbon neutral, and once wood pellet supply chain emissions are counted, biomass is classified as low carbon.
What’s more, with our pioneering bioenergy carbon capture and storage (BECCS) project, we’re aiming to go beyond carbon neutral and become carbon negative by removing more carbon dioxide (CO2) from the atmosphere than is produced in our operations.
How biomass power generation works
Functionally, biomass is like other thermal fuels such as coal and gas. Its use creates steam, which is used to drive massive turbines that generate electricity. The difference is that using biomass creates significantly lower carbon emissions.
Over the last 10 years or so, renewable power sources that depend on weather conditions, such as wind and solar, have proliferated. These have helped to green up the grid and reduce the carbon intensity of the UK’s power network.
However, this increase has also introduced new challenges for the power system operator (National Grid ESO) regarding the stability of the grid, which needs constant fine-tuning. As biomass is a more flexible source of power, the operator can call upon Drax Power Station at short notice to help balance the grid. For example, this could happen to meet demand when the sun isn’t shining, or the wind blowing.
The biomass we use at Drax Power Station accounts for around 12% of the UK’s total renewable power electricity mix. Analysis by researchers working at Imperial College London found that from 2010 to 2019, biomass generated more power than solar panels and provided an outsize contribution to reducing emissions and wholesale power prices.
Our commitment to sustainable biomass sourcing
We work with several partners to make sure our biomass is responsibly sourced and part of the Sustainable Biomass Program. We’ve also established Independent Advisory Board, composed of leading scientists and sustainability specialists to help ensure our biomass production continues to contribute to the environment in a positive way.
Want to learn more about biomass?
To find out more about sustainable biomass, you can read about our commitment to giving up coal before the government’s 2025 deadline, and our responsible sourcing policy. You can also see ForestScope, a visualisation of the steps we’re taking to ensure our biomass supply chain is better for our forests, our planet and our future.Download our biomass sustainability factsheet here