“Energy supply units will be smaller in size”

How can regenerative resources make the best possible contribution to our energy supply? This is the key issue on the bioenergy agenda for Professor Daniela Thrän, who heads the Bioenergy Systems Department at the German Biomass Research Centre (DBFZ) and the Bioenergy Department at the Helmholtz Centre for Environmental Research (UFZ). She expects energy supply units to shrink in future, with more targeted use of bioenergy in combination with other energies.

Professor Thrän, what is the best contribution that bioenergy can make?
That question has both a scientific and a societal dimension. The best contribution that it can make will, of course, depend on the opportunities and limits to bioenergy use, and it will also depend on society’s objectives. Let’s take the example of climate change and energy supply security. As we know, these can be conflicting agendas. If we want to reduce greenhouse gas emissions, we have to focus mainly on the power generation industry, but if we want to reduce our dependency on crisis regions, transport is a more relevant sector. We have to adopt an integrated approach to the multitude of issues relating to climate and energy supply security, and we also need to consider land use, resource availability, food security and the available technologies in order to answer the question.

What role will bioenergy play in future?
The key issue will be bioenergy quality, not quantity. Energy supply units will be smaller in size. A key aspect is to close the gaps left by other forms of energy, combining various energy products. For example, power should be generated from biomass on days when there is no sunshine or wind. It’s important to make use of the opportunities to couple several forms of energy.

What will this mean in practice?
By combining material and energy use, we can increase biomass efficiency. That is already happening. For example, one of the by-products of diesel production is what is known as a press cake, which is used in the animal feed industry. There are similar linkages in the timber industry as well: each kilo of timber is now used 1.6 times in Europe. This combined use is not always straightforward, so expansion will be progressive. We shouldn’t expect too much too soon.

How high is public acceptance of bioenergy, in your view?
I think that acceptance has a lot to do with the level of knowledge, and it also has to do with perceived benefits. That was the problem with E10 initially, although acceptance has now increased. But at first, there was considerable resistance from the oil and car industries, and consumers weren’t sure why they should be using E10. I believe we should be focusing more on consultation and spatial integration. For example, if a community sets up a biogas plant, and if the feedstock is supplied by local farmers and the heat generated is used to supply the village, the level of acceptance will automatically be higher.

What opportunities exist to use biofuels in the aviation industry?
There are various initiatives under way at present, which focus on oil-rich biomass, algae feedstocks and conversion of biomass into synthetic gas and then bio-kerosene. There is firm evidence that biofuels can be used in this industry: many airlines have already conducted trials. The problem is that these biofuels are more expensive than fossil-based kerosene.

Even so, how can biofuels be promoted in this industry?
Mandatory climate commitments for the aviation industry are one option. However, the solutions have to be found at the international level, as this will involve setting up appropriate infrastructure at the world’s major airports and hubs. And of course, we need pioneers, such as airlines that are willing to trial biofuels in their regular operations, not just on occasional test flights.

Thank you for talking to eco@work.

The interviewer was Christiane Weihe.