The impact on the climate of the use of forest biomass for energy is a combination of emissions from its combustion, its supply chain and the impact on carbon stocks in the forests from which it was sourced.
This chapter reviews current patterns of demand for wood for energy in the EU and the UK, and the feedstock sources which supply it. It includes the figures for the CO₂ emissions from biomass combustion in the EU and UK reported to the UNFCCC, but also provides a more complete analysis of the levels of carbon emissions associated with the use of US-sourced biomass for energy. The emissions associated with the consumption of US-sourced biomass in the EU, UK and Drax are calculated from the combustion of wood pellets, from the energy used in the supply chain (harvesting, processing and transport) and from the impact on forest carbon emissions and stocks in the forests in the southern US from which the pellets are sourced. The detailed methodology for each of these calculations can be found in the Annex.
3.1 Biomass for energy in the EU
Over the last ten years the former EU28 has been the main global source of demand for wood for modern (non-traditional) uses of biomass for power and heat. This has been a result largely of the policy support frameworks put in place by EU member states following the 2009 Renewable Energy Directive, which set targets to be achieved by each member state for the proportion of energy supplied by renewables by 2020. This framework has led to the EU27’s share of final energy consumption from renewables more than doubling between 2004 (9.6 per cent) and 2019 (19.7 per cent). The overall EU target of 20 per cent by 2020 is expected to be met, as several member states have overshot their targets, compensating for the few that are likely to have failed to meet them.
All sources of renewable energy in the EU have grown, including bioenergy, which is the largest single source, accounting for 60 per cent of gross consumption of renewable energy in 2018. Solid biomass accounted for 68.4 per cent of that figure (i.e. 41 per cent of renewable energy), with the remainder comprising renewable municipal waste, bioliquids and biogas. Across the former EU28, solid biomass supplied 9 per cent of generation of electricity from renewable sources (3 per cent of total electricity generation) and 76 per cent of heat from renewable sources (15 per cent of total heat).
In fact, the proportion of renewable energy accounted for by solid biomass has slowly fallen in recent years, even as total consumption has increased. This is due to the faster rates of growth of other renewable technologies, particularly wind and solar for electricity. Alternative sources of renewable heat are not as strongly commercialized, however, and to date they have received lower levels of government support. As a result, solid biomass can probably expect to retain its dominant position for renewable heat for several years to come.
3.2 Biomass for energy in the UK
Of all 28 EU member states, the UK saw the greatest growth in the use of biomass for electricity in absolute terms. Between 2009 and 2019, the use of biomass for electricity in the UK grew by an average of 23 per cent per year, faster than the 19 per cent average annual growth rate of electricity from renewables as a whole – which was itself high by EU standards. In 2018 the UK accounted for 24 per cent of all electricity generated from biomass throughout the EU. As in other countries, the growth rates of electricity in the UK from wind and solar have been faster in recent years, meaning that biomass is gradually falling as a proportion of total renewable electricity generation. In 2018 biomass accounted for 22 per cent of renewable electricity generation (7 per cent of total electricity), down from 25 per cent in 2015.
Although some dedicated biomass power plants have been built (and one large one is still under construction), the growing demand for biomass power has largely been due to the replacement of coal, originally through co-firing with biomass but more significantly through the conversion of coal stations to biomass, in particular the conversions of four of the six units at the Drax power station. (Co-firing has now ended after reductions in government support.) The last coal station to be built in the UK, Drax is also the largest (with approximately 4 GW capacity), supplying about 7 per cent of all UK electricity. It began co-firing wood pellets with coal in 2003 and fully converted its first unit to biomass in 2013. Conversion of the fourth unit was completed in 2018. (Drax does not plan to convert the remaining two units.) By 2019, some 95 per cent of the electricity generated by the plant was derived from biomass. Drax is the largest biomass-burning power station in the world, consuming more than 7 million tonnes of wood pellets in both 2018 and 2019.
The UK is not on track to meet its 2020 Renewable Energy Directive target of 15 per cent of energy from renewable sources, however, because of much slower progress in the development of renewable heat and transport. As in other EU member states, solid biomass is the main source of renewable heat generation, accounting for 78 per cent in 2018 but only 5 per cent of the overall total. In fact, this proportion has increased slightly since 2015, as growth in other renewable technologies has slowed down.
3.3 Production, consumption and trade of wood pellets
As well as being a major consumer of wood for energy, the EU is also a major producer. Over the last forty years the volume of wood harvested for energy in the EU has steadily risen, alongside harvests for other purposes, both in absolute terms and as a proportion: 22.7 per cent of roundwood production was harvested specifically for energy in 2017, compared to 18.7 per cent in 2000. However, due to the use of wood and associated products not specifically harvested for energy (such as residues and black liquor), total woody biomass consumption for energy is much higher. In 2014 an estimated 42 per cent of harvested EU wood was used for energy. As noted in Chapter Two, the 2021 JRC study concluded that over the period 2009–15, 49 per cent of wood-based bioenergy production in the EU derived from secondary woody biomass (forest-based industry by-products and recovered post-consumer wood) and 37 per cent from primary woody biomass harvested from forests, with the remaining 14 per cent uncategorized, but likely also to be primary wood.
An increasing proportion of the woody biomass burnt for energy is now in the form of pellets, which could be produced from any of these sources. The EU is now the world’s largest producer of wood pellets: in 2018 the EU produced 16.9 million tonnes of pellets, accounting for 46 per cent of the world’s total production of 38.9 million tonnes. However, the EU is a net importer of pellets, as its total consumption of wood for energy is higher than production.
The EU is now the world’s largest producer of wood pellets: in 2018 the EU produced 16.9 million tonnes of pellets, accounting for 46 per cent of the world’s total production of 38.9 million tonnes.
Data for 2017 from the Food and Agriculture Organization of the UN (FAO) indicate that imports accounted for 9.4 per cent of total primary energy production from solid biomass. While some wood fuel and other feedstocks are imported, the main international trade is in wood pellets, which, as noted above, are much easier to store and transport over long distances than other wood feedstocks. Imports of pellets from outside the former EU28 rose to 10.3 million tonnes in 2018, almost five times the quantity imported in 2010 (see Figure 1). This accounted for almost 40 per cent of total former EU28 consumption of wood pellets. The US has been the largest single source of imports from outside the EU, accounting for 59 per cent by weight of former EU28 imports of wood pellets in 2019.
