Difficult and costly energy transition projected by experts unless EU invests in biomass

Biomass is currently the EU’s largest renewable energy source, but climate strategies often focus on other energy sources. A comprehensive analysis, led by Chalmers University of Technology in Sweden, now shows that biomass is crucial for Europe’s ability to reach its climate targets, as it can be used to produce fossil-free fuels and chemicals and also enables carbon dioxide removal from the atmosphere. If biomass were excluded from the European energy system, it would cost an extra 169 billion Euros per year—about the same as the cost of excluding wind power.

Biomass, such as energy crops, logging residues, cereal straw and wood waste, is a versatile source of renewable energy that many industries want to use to reduce their greenhouse gas emissions. Biomass can replace fossil fuels, for example in the steel and cement industries and in power plants that supply households with electricity and district heating. It can also replace oil and fossil gas in the production of plastics and chemicals, as well as the production of fuels for vehicles, shipping and aviation.

In addition, biomass can play a key role in an increasingly important part of the climate transition: carbon dioxide removal from the atmosphere, via carbon capture and storage (CCS). The carbon atoms in biomass have been absorbed from the air through plant photosynthesis.

Normally, when biomass is used for energy the carbon atoms are released back into the air as carbon dioxide. But when bioenergy is combined with CCS, those carbon dioxide emissions are avoided. Biomass use with CCS therefore provides energy along with carbon dioxide removal from the atmosphere, which is known as negative emissions.

Rapidly increasing costs if the amount of biomass is reduced

With growing demand for non-fossil alternatives, the competition for renewable resources has intensified—prompting policymakers and industry to address questions about policies and investments into resources and technologies that effectively support the energy sector’s climate transition.

As biomass has so many uses, scientists are grappling with questions about the role of bioenergy in the energy system. How is the energy sector’s climate transition affected by the varying availability of biomass? How and where is biomass best used?

In a paper in Nature Energy, researchers at Chalmers University of Technology, Rise Research Institutes of Sweden and Technische Universität Berlin have carried out a comprehensive analysis and shown what a future European energy system could look like—including electricity, heating, industry and transport.

The researchers investigated two emissions targets for the energy system; one with zero emissions of carbon dioxide and one with negative emissions (minus 110% compared to 1990). The biomass in the system consists mainly of waste material from forestry and agriculture within Europe, plus a more expensive part which can be imported.

The study’s lead author, Markus Millinger, a researcher at Chalmers when the study was conducted and now a researcher at Rise, notes that biomass plays an unexpectedly important role in the energy transition.

“One thing that surprised us was how quickly it becomes very expensive if we reduce the availability of biomass in the energy system, due to the high costs of alternatives. If biomass is completely excluded, the costs of the energy system with negative emissions would increase by 169 billion Euros annually, compared to the same system with a cost-optimal level of biomass. This is an increase of 20%, which roughly corresponds to the cost of excluding wind power.”

If biomass availability is limited to the current level of biomass use in the European energy system, the additional cost is 5% compared to the cost-optimal level.

“But the financial part is perhaps not the largest problem,” says Millinger. “The big difficulty may be to scale up the alternatives. Even with biomass in the system, it is a real challenge to expand fossil-free energy to the extent needed. Further restrictions on the supply of biomass would make the energy transition very difficult, as even larger amounts of other types of fossil-free energy would be needed.

“In addition, we would miss out on the opportunity for negative emissions that the utilization of biomass provides. To then achieve negative emissions in the energy sector, carbon capture directly from the air would instead have to be scaled up to a large extent. This is a significantly more expensive technology that requires an energy input instead of providing a net energy output.”

Capturing carbon dioxide is most important

A central conclusion of the study is that the value of biomass in the energy system is primarily linked to the fact that it contains carbon atoms. Biomass as an energy source is less important. The large-scale technologies we have today to utilize the energy content of biomass, for example by burning it in power plants, can be combined with technologies to capture the carbon dioxide in the waste gases. Then the carbon dioxide can either be stored permanently underground or reused as a building block in products such as fuels and chemicals.

Biomass can thus supply energy and simultaneously enable negative emissions or replace fossil raw materials. And it is the latter opportunities that have now proven to be most important for the climate transition. Consequently, it is crucial that the carbon atoms are captured to be stored or reused efficiently, but it matters less how the energy content of biomass is used.

“As long as the carbon atoms are utilized, it is not crucial in which sector biomass is used, except that it is an advantage to use a small share of the biomass as a flexible reserve for electricity production to strengthen supply reliability,” says Millinger.

“Factors such as regional conditions and existing technical infrastructure are therefore important to determine what is most favorable. This means that countries can choose different paths if they want to use biomass to achieve negative emissions—for example via the production of electrical power, heat or biofuels.”

Provides an expanded knowledge base for policy development

The researchers have used an advanced model that includes more technologies and a higher level of detail than previous similar studies. The model also shows how all society sectors affect each other within the energy system. The new study thus provides an expanded knowledge base for policy development—not least linked to biomass and technologies for negative emissions.

“The capture and storage or reuse of carbon dioxide, for example through the production of advanced fuels, is dependent on large investments to get started, and long-term sustainable and reliable value chains need to be built. A market for fossil-free carbon dioxide would significantly strengthen the opportunities for such investments compared to today, when it is primarily the energy that is valued. But this requires that decision-makers create stable policy instruments to realize the great value of fossil-free carbon atoms within the climate transition,” says Millinger.

Technology development and policy have stimulated an increasing utilization of bioenergy in the EU. But there are also policy instruments that limit its use in various ways, based on concerns about possible negative effects such as higher food prices, deforestation and loss of biodiversity.

“The bioenergy sector is developing in a context where agriculture and forestry are meeting increasing sustainability requirements,” says Göran Berndes, co-author of the study and Professor of Biomass and land use at Chalmers. “Given that the climate transition is expected to increase the pressure on forests and agricultural land, it is important that there are regulatory systems that lead the development in a positive direction.”

“At the same time, bioenergy systems can be designed to contribute to more efficient use of resources and mitigation of the negative environmental effects of current land use. If policy instruments are designed to reward landowners and other actors for ‘doing the right thing,’ this in itself can drive development away from environmentally harmful activities,” says Berndes.