‘If you looked at everything we have in the UK and everything we could grow, we end up with a figure between 10 and 20%, split across fuel, heating and energy’, says Professor Patricia Thornley, referring to the percentage of biomass consumed in different markets. She is the Director of Aston University’s Supergen Bioenergy Hub, which brings together academia and industry, and provided scientific evidence to inform the UK government’s Strategy.

The difference between 10 and 20% is a pretty big disparity and that is all part of the sustainable bioenergy conundrum. Professor Thornley admits: ‘The question which the Biomass Strategy didn’t really answer is how you prioritise between those different uses.’ What’s self-evident, she adds, is that in the near term at least you do things that reduce carbon.

The biomass brew
The UK currently produces around 65% of its biomass supply and imports most of the rest from the US and Canada, but not Russia these days. Home-produced biomass comprises a rich organic brew of things like crops, food and animal waste, wood and timber. Thanks to the conversion of power plants like Drax – from coal to wood pellets – and the IronBridge plant in Severn Gorge, currently the largest pure biomass plant in the world, most of this domestic production goes towards generating electricity, while biodiesel and bioethanol are both important contributors in meeting the Renewable Transport Fuel Obligation (RTFO).

Aside from competing demands for bioenergy – another one is aviation fuel – the issue for the UK government, and indeed other governments, is what constitutes sustainability when you are trying to get to net zero.

In his Foreword to the government’s Biomass Strategy, Graham Stuart, the UK Minister for Energy Security and Net Zero, notes somewhat vaguely that there are plans to consult on a sustainability framework. Various forestry schemes such as the Sustainable Biomass Programme and the Forestry Stewardship Council already offer certification for woody biomass, aiming to protect virgin forest and prevent deforestation.

A key challenge, notes Stuart, ‘is the scaling up of domestic biomass supply, without compromising food security’. At the moment, around 121,000 hectares (ha) in the UK are used to grow biomass crops for energy. The key question is how much more land would you want to use for this purpose and what kind of additional plants might fit the bill?

More biomass, more land
The answer to the first question is about 750,000 ha of land by 2050 without any adverse impact on food production, according to the UK Climate Change Committee (CCC). Examples given are perennial biomass crops like willow and miscanthus for short rotation coppicing, but there is clearly still a long way to go. In 2022 some 34% of UK biomass was imported, mostly comprising wood pellets from the US and Canada, all destined for the UK’s big power plants.

While environmentalists question the sustainability of importing wood pellets, albeit from waste timber, to plug the gap, Professor Thornley suggests that if we are trying to save the planet as a whole we need to see things in the round. ‘The UK’s emissions are much greater by consumption than its territorial emissions, but we have to look at what’s best for the planet. At the moment, in terms of CO₂ uptake, forestry residues from another country sits on the books (in theory at least) as a carbon credit for that country. There currently isn’t a mechanism which gives the UK a credit for sinking that CO₂,’ she notes.

While bioenergy beats fossil fuel as a lower carbon solution, ‘in the medium to long term it needs to be integrated with carbon capture and storage (BECCS) as part of a forward looking net zero solution’, says Professor Thornley. ‘The UK (and the global energy system) needs CO₂ removals to deliver net zero. BECCS has an absolutely key role to play, as reflected in the Strategy. While this is encouraging, we must not underestimate the challenges of moving towards such a radically different system at scale,’ she adds.

This includes two important ingredients, she suggests: moving away from bolt-on CCS solutions which can be less efficient, and in many cases too costly for an industrial business case, and using biomass with BECCS to produce hydrogen which can be used to power industry and heavy transport.

‘This is really important as it’s taking a resource we have to produce hydrogen and doing it in a way that actually delivers negative emissions. At the moment, there is a tendency to stick to what we know. But this is the most important bioenergy technology we should be developing and there are lots of ways to do it,’ remarks Professor Thornley.

‘In the medium to long term it needs to be integrated with carbon capture and storage (BECCS) as part of a forward looking net zero solution.’ – Professor Patricia Thornley, Aston University’s Supergen Bioenergy Hub

Drax to invest in carbon capture
In the meantime, the UK government is putting its faith in a bolt-on BECCS solution at the Drax power station in North Yorkshire where it announced (in January 2024) a scheme to bolt two carbon capture plants onto Drax’s four existing generating units. The £2bn BECCS investment will help it become the first carbon-negative power station and create 10,000 jobs at the peak of construction, notes Drax management.

‘BECCS is the only credible large-scale technology that can generate secure renewable power and deliver carbon removals,’ says Drax Group CEO Will Gardiner. ‘The development of BECCS... will ensure that it can continue to play a critical role in UK energy security... as more intermittent generation comes online and older nuclear plants are decommissioned.’

For her part, Professor Thornley remains focused on the R&D and innovation which she believes must help to drive the UK’s energy future. The Biomass Strategy seeks to endorse this approach with the announcement of a further £32mn to support the government’s biomass feedstocks innovation programme. While the first phase provided £4mn to test the design and feasibility of 12 projects, the second phase will take successful projects through to implementation and will conclude in March 2025. An additional £5mn has been awarded to support 22 projects that generate hydrogen from biomass and waste.

Time to prioritise
While the UK is among the most innovative nations in the world in this area, it struggles with both the prioritisation of projects and with scale – the development end of R&D. The Biomass Strategy acknowledges this without offering hard and fast solutions – other than the need to prioritise better – and to be realistic about the limited but better invested and more focused contribution BECCS can make to net zero.

‘Relying on future BECCS deployment alone to counterbalance the current excess of greenhouse gas emissions would not enable the full potential and benefits of BECCS,’ suggests Dr Joanna Sparks, Biomass Policy Fellow at the Supergen Bioenergy Hub. ‘BECCS should be deployed alongside measures to transition away from the use of fossil fuels, not instead of them,’ she argues.

The bioenergy options enthusiastically being taken forward by academics and startups are myriad, notes Professor Thornley. It comes back to consolidating the cash following what can be a scatter-gun approach to government support.

The gasification of hydrogen, the synthesis of chemicals and materials from biomass (eg plastics and polymers), and the use of artificial intelligence (AI) to see how bioenergy performance can be optimised, are all part of the latest R&D voyage of discovery. The diversity of these approaches are another reason why Professor Thornley offers such a wide-ranging estimate as to the contribution that bioenergy could eventually make to the UK sustainable energy mix.

International leadership
For all its efforts, the UK still lags behind a number of countries in the development of bioenergy, mainly through a shortage of home-produced biomass resources.

Sweden, for example, is a global leader in sustainable bioenergy, having successfully transitioned to a bioenergy-based heating system and extensive use of biofuels for transportation. The reasons are twofold: the country has a relatively small population – at just over 10 million it is about a sixth of the UK – and 69% of Sweden is covered with forest. This means it can concentrate its efforts on producing advanced biofuels derived from forest residues as well as agricultural waste.

Another major player and pioneer in the field is Brazil, which derives large amounts of bioethanol from sugar cane. This means that a big slice of the country’s transportation fuel comes from renewable sources, a key factor in its economic growth. The US (non-food biomass), Denmark (straw and wood chips) and Singapore (waste-to-energy) all utilise bioenergy and have successful large-scale facilities up and running.

In the UK it remains to be seen how much the Biomass Strategy will help to drive progress in producing more sustainable bioenergy, so long as there can be agreement both in the UK and internationally on what ‘sustainable’ means in this context. (The National Audit Office has recently questioned the government’s analysis of biomass sustainability.)

Understandably, Drax’s Gardiner remains bullish, noting that that the UK government wants to deploy 5mn tonnes of carbon removals by 2030. BECCS at Drax and more policy support in the future will inevitably have to be part of the solution.