Liquid Sunlight: research for better insight into photosynthesis


Plants are experts in using sunlight. They use it to transform water and carbon dioxide into sugars and oxygen. Wageningen researcher can mimic and improve this process. Through that, they want to create bio fuels and better growing crops.

The world currently remains heavily dependent on fossil fuels. This dependence results in excessive carbon dioxide in the air, and that leads to global warming. Researchers in Wageningen have now found a method of scavenging carbon dioxide from the air, and combining it with clean water to make biofuel. The energy for this comes from the sun. The process has the potential for small-scale, inexpensive production, and for bringing about a revolution in energy supply.
Research leader René Klein Lankhorst of Wageningen University and Research says: "Now that we have demonstrated that we can make biofuel from water and carbon dioxide, we want to scale up the process. The ultimate target is appliances on roofs that produce liquid fuel. People can then use this fuel for their lighting, for their car, or for the generation of electricity."

Importance of research and Impact on society

Importance of research
Solar panels for generating electricity with sunlight are a good alternative to fossil fuels, but only 20 percent of the global energy supply is provided by electricity. For the remaining 80 percent, we are still dependent on liquid fuels such as petrol or diesel, or gaseous fuels such as LPG.

Although biofuels made of crops or crop residues are cleaner, this solution has drawbacks. Land for growing biofuels is scarce, and crop residues are also needed to sustain soil fertility. In this project, the Liquid Sunlight researchers are using ingredients whose supply is
almost limitless: sunlight, water and carbon dioxide.

Impact on society
Biofuels are being produced by artificial leaves. "Here we are emulating the process of photosynthesis in plants" says Klein Lankhorst. "Photosynthesis is the most important
process on earth. Plants use sunlight to convert water and carbon dioxide into oxygen and carbonaceous products such as glucose." Citizens or companies can simply put the artificial leaves on their roofs. Through such large-scale production, fossil fuels will no longer be required. The fuel obtained by the process can also be used as an input for the making of plastic. And this technique allows solar energy to be stored in a convenient form, available even when the sun is not shining.

History and René Klein Lankhorst's dream

The reason for the research in Wageningen was the development of artificial leaves by other universities. The first of these leaves split water into oxygen and hydrogen using solar energy. The Wageningen researchers went in search of enzymes that would convert this split water into methanol by combining it with carbon dioxide. They found these enzymes in a test tube, where they obtained methanol with the help of some chemicals and two enzymes. The process takes place at normal atmospheric pressure and temperature. Klein Lankhorst says: "In our new project, we want to link this process to an artificial leaf built by the University of Leiden."
A conventional solar panel converts the charge emitted by solar energy into electricity. This artificial leaf from Leiden uses the charge to split water into oxygen and hydrogen gas. The Wageningen researchers now want to attach enzymes in a way that produces methanol instead of hydrogen.

René Klein Lankhorst’s dream
The dream of René Klein Lankhorst is that soon in developing countries, the roofs will be covered with appliances that mimic photosynthesis. "People could just pour fuel from a tap. That could be inexpensive, if we can find cheap materials and chemicals for the appliances. And it is clean, because the same amount of carbon dioxide is captured as will be released by burning. Storage and transportation will also be unnecessary, because the fuels are made on site."
Producing fuels at a local scale is a particular advantage in developing countries says Klein Lankhorst, because these countries often lack the infrastructure for storage and transportation of oil-based and other fuels.

The strength of Wageningen University & Research

Wageningen University & Research has the right credentials to do this research. Klein Lankhorst was general manager of the Dutch Biosolar Cells programme. In this extensive 42 million euro programme, ten research institutes and 39 companies worked for five years on ideas to study and improve the photosynthesis process. During this programme, which expired in 2016, the principle of converting water and carbon dioxide into liquid fuel was successfully demonstrated, and the method was defined in patents. Wageningen is now examining the possibility of setting up a spin-off company based on this technology.

Who are the partners?

The Wageningen researchers will continue to work with the BioSolar Cells partnership, including Leiden University, the Technical Universities of Delft and Twente, and BioMCN, a manufacturer of biomethanol from Delfzijl.


The Liquid Sunlight project will run for seven years and is budgeted at five million euro. In the first year, researchers from Wageningen will link the Liquid Sunlight technology to the prototype of the artificial leaf. In the second to the fifth years, a group of PhD students will increase efficiency and robustness, and search for inexpensive chemicals. In the final two years, the artificial leaf, which currently measures 20 by 20 centimetres, will be scaled up to ten square meters. A detailed budget will be sent on request.