Storing energy by using enzymes
We are on the cusp of a large-scale energy transition – a huge task that requires the development of not only renewable energy sources from wind and sun, but also energy storage. Wageningen University & Research (WUR) scientists Jules Beekwilder and René Klein Lankhorst think that enzymes can help us solve the latter challenge.
WHY THIS RESEARCH?
As sustainable energy sources such as wind and sun are not as constant as traditional power plants, storage will become a crucial part of the new energy landscape.
Enzymes that help convert sun and wind energy surpluses into methanol that can be stored and combusted as needed.
“Our concept involves an artificial variant of photosynthesis with which plants convert sunlight and CO₂ into glucose and other carbohydrates in order to grow,” says Beekwilder. “We are trying to mimic this with enzymes so that we can make an energy-rich substance like methanol from energy-poor CO₂. This is possible if you add energy, for example in the form of electricity generated by sun or wind. Our procedure converts that electricity into methanol, which can later be combusted to release new energy and act as energy storage.”
‘We can convert electricity into methanol, which can later be combusted to release that energy. This is a form of energy storage’
“That methanol can also be used as a clean raw material for chemical applications. Our procedure now works in the lab, and we would very much like to start using on at a larger scale. There is enormous potential for temporarily storing wind and solar energy surpluses and for fixing the huge amounts of CO₂ needed for the process.”
The findings of the scientists combine aspects of biochemistry and electrochemistry, enabling the fast development of products that can easily be used in existing energy and chemical systems. “Our process leads to an intermediary product that itself is already useful in itself,” Klein Lankhorst says. We start with an enzyme that can bind hydrogen to CO₂. This results in formic acid, a product that buses can use as fuel, for example. Next, a second enzyme converts the formic acid to methanol. We are still working on the question of how to optimise each enzyme so that it does exactly what we want, preferably in a way that’s both affordable and efficient. Experimenting with this leads to uniform products at each step of the process – literally in a test tube, as it were. The challenge is to translate this into real-life chemical applications with a constant value added in large systems and tanks.”
ELEGANT CHEMICAL APPLICATIONS WITH ENORMOUS POTENTIAL
“What makes this process attractive is that this can take place at normal temperatures and without using things like pressure tanks. This is very different from other chemical processes, which require high temperatures and a lot of energy to get results. These are elegant applications that have had little global attention up to now, but which have an enormous potential to enrich the economy and society of the future. When we one day massively convert to sustainable energy sources, the energy landscape will become less stable. Sun and wind are simply not as constant as coal-fired power plants.”
Prototype of a photoelectrochemical cell. Photo: Leidsch Dagblad
Energy storage is going to play a crucial role in the continuity of our energy supply. “WUR can play an important role in this,” Beekwilder continues. “In fact, I sometimes think: if WUR does not do this, who will? Who is going to help make energy storage sustainable and clean? We have to play a pioneering role because this is our domain. And that in itself is inspiring. Everything can come together in this project, which touches upon almost every discipline at our university. But that also makes it difficult to finance as its multidisciplinary character is difficult to express in the usual terms. So we are looking for alternatives – this discovery is too good and important to be ignored.”
Dr René Klein Lankhorst
Programme Developer Plant Research, Wageningen University & Research
Biobased economy, Biotechnology, Chemistry, Molecular biology, Molecular breeding, Algae cultivation, Photosynthesis, Greenhouse gasses, Sustainable energy, CO2
Photo: Gea Hogeveen