Prof. Ralf Seppelt, Helmholtz-Zentrum für Umweltforschung - UFZ zur Frage, ob Pflanzen zur Energiegewinnung genutzt werden sollten.
DW: Is Miscanthus-grass a biomass source of energy?
Prof. Ralf Seppelt: It has a very good advantage compared to all the other crops that are well known for biomass production. It uses less water, less nitrogen, less pesticide, and it covers the ground, so it also reduces erosion. That is a very good point. However, I would like to put this in a broader context and compare it to all the other options we have, and what we can do. We could put it to use in the land, agricultural production, and infrastructure to preserve nature. And the point is, if we use biomass just for burning, then I think it’s really less efficient than all the other options we would have for producing energy, like for instance wind power, solar energy or whatsoever.
So it may not necessarily be the best energy source. However, supporters of biomass would say that it is carbon neutral, for example.
If you look the photosynthetic processes take up carbon from the atmosphere, released through burning, that is perfectly true. However, if you look at the whole value chain, and the production, and if you look at our hunger for biomass as we should use it, and as German legislation has asked for, it has some negative effects and trade-offs for other existing functions. Then it is really worth considering doing something more efficient, for instance, wind power or solar energy.
That brings me onto the hunger for biomass, and the also big debate that it involves about the ethics of biomass use. We are essentially using this land to fill it with a grass, and then burning it instead of feeding people.
Yes, actually, what we do here is we have some indirect effects also to other countries in the world with our hunger for bio-energy. It has some effects on Brazil, on Mexico, on south-east Asia, and other countries. And implying there is some land use change, and this again leads to emissions of CO2. But anyhow, it also has some positive sides. So using this as a material - for instance for planting pots for insulation. We will reach the point where we need some materials that can not be produced out of oil or fossil material. We will reach the point where need to find some substitutes made out of plants. And this is where Miscanthus might be a pretty good plant.
Is it a good plant in order to substitute or to be an ingredient in a plastic, for example?
It could be. Actually, there is very little research on this, and it would be really highly important to figure this out.
Perhaps we should just use agricultural waste products as biomass.
It could be. However, agricultural waste products are much more heterogeneous in terms of their substances compared to Miscanthus. It is much more homogeneous.