Peter Werkhoven: Solar fluids - Innovation then and now

Our ancestors created the first rock art and developed innovative stone axes about 120,000 years ago – between two ice ages – in temperatures similar to today’s. That warm period had lasted longer than the present one, so sea levels were more than six metres higher than they are now. This is reason enough to reduce our high CO₂ concentration and high temperatures. And the first thing we think of is renewable energy production, from the sun and the wind. Yet this kind of production is quite erratic, so it is vital that we find a way of buffering energy.

Imitating nature

Our efforts to find solutions for transforming and storing energy are focused on particles which, even though they are a million times smaller than a stone axe, could radically change the energy world. At Eindhoven, Pascal Buskens (our top researcher) and his team are working on nanoparticles that can help us to closely imitate nature, using a highly efficient process by which the energy of sunlight is stored in useful substances such as hydrocarbons or alcohol. You can visualize these particles as gold nanorods suspended in water, which function as ultra-small, light-absorbing antennas. A tiny zone of high temperature and pressure develops close to each particle’s surface, turning them into chemical nanoreactors. Tiny reactors like this, in liquids at room temperature, are also known as solar fluids.

Fuels from the sun, from water and from CO₂

Imagine a kind of solar panel that, instead of electricity-producing silicon solar cells, contains solar fluids that produce fuel. The idea of using this technology to convert CO₂ and water into methanol or dimethyl ether, for example, is something of a holy grail. The current two-step process could be replaced with a single step, resulting in greater efficiency. This is because the new technology eliminates the need to first use solar cells to convert sunlight to electricity (which is only 20% efficient), and then to use that energy for the production of fuels (which is only 70% efficient). Solar fluids could transform electric vehicles into an intermediate step in the evolution of CO₂-neutral cars (or trucks) powered by fuels produced from sunlight. Using nanoparticles to create a mega impact!