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Wil Sillen

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Climate love

Giant dish produces hydrogen from sunlight

Researchers at the Swiss Technical University of Lausanne (EPFL) built a dish-like reactor that can produce hydrogen from sunlight and water. The oxygen that remains after this process can be used by hospitals, while the residual heat can be used to heat water.
It looks like a large metal satellite dish. Yet EPFL's solar reactor does not emit signals, but produces hydrogen. This is done with solar energy and water.
By: Romy de Weert

Photoelectrochemical reactor
The device works as follows. The dish captures as much sunlight as possible and directs the light to the center point of the dish. There is a photo-electrochemical reactor, including a photocatalyst. A photocatalyst is a material that can absorb light energy and use it to speed up a chemical reaction.

So when light falls on the photocatalyst, a reaction takes place in which the water molecules are split into hydrogen and oxygen. The use of a photoelectrochemical reactor is a sustainable way to produce hydrogen. Unlike, for example, gray hydrogen, which requires fossil fuels to split water molecules.

Half a kilo of hydrogen every day
By producing half a kilo of hydrogen every day, the solar reactor can supply up to half of the Swiss electricity demand of an average four-person household.

Although the production of hydrogen is the main purpose of the solar reactor, heat and oxygen are also released. “In the production of hydrogen, the two are often seen as a waste product,” says Sophia Haussener, head of the Laboratory of Renewable Energy and Engineering (LRESE) at the School of Engineering. In this case, the oxygen can be used for medical applications. The residual heat can be used to heat buildings.

Demo factory at metal manufacturer
The project, set up in 2020, led to the spin-off SoHHytec. The start-up is now working with a Swiss metal producer to build a demonstration plant on a larger scale. The hydrogen will be used to heat the metal. The oxygen is for the nearby hospitals and the heat is used to heat the water in the factory.

Split CO2
In addition, researcher Haussener is exploring new technologies comparable to the technique of the solar reactor (artificial photosynthesis). For example, the lab is working on a large-scale solar energy system that can split CO2 instead of water. This leaves usable raw materials, such as the liquid fuel syngas.

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  • Tabitha Kimani

    5 w

    Technology is the real deal.

    • Kevin

      5 w


      • Mc Kaka

        5 w

        Very interesting!

        • Ajema Lydiah

          5 w

          creative and interesting

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