Waterguide - The economic potential of green hydrogen

What is "Power-to-X"?

So-called "power-to-X technologies" are making a significant contribution to climate protection. Green hydrogen from renewables has the potential to become the energy source of the future. The production costs for the energy-intensive process are falling and hydrogen can play the role of a storage device in the medium term. But what is hidden behind the bulky term "Power-to-X"?

The idea is quite simple: sometimes wind turbines and solar parks convert more energy into electricity as demanded or consumed. This occurs mainly on very windy days at noon, or in the case of solar power on very sunny days in midsummer. Currently, this surplus electricity from wind and solar power cannot be stored in batteries. The idea of Power-to-X is to use the energy to produce hydrogen, which can be converted back into electricity during "dark periods". The hydrogen produced by renewable energy is called green hydrogen. This green hydrogen can be stored, transported and used in industry as required. It avoids the use of fossil fuels and, as a consequence, the generation of emissions that are harmful to the climate. For this reason, the German government is promoting the production of green hydrogen as the energy carrier of the future in its National Hydrogen Strategy.

The importance of water treatment facilities in the industrial production of green hydrogen

Green hydrogen is produced on the basis of treated water through electrolysis. During the electrolysis water molecules are split into hydrogen and oxygen. The required energy for this process is supplied by wind and solar energy. In addition, the quality of the water is important. Besides renewable energy, the conversion process requires the resource pure water. Water treatment devices are able to produce the pure water needed for the production of green hydrogen. Depending on the application, mobile or permanently installed plants can be used. Thereby, reverse osmosis plays a central role.

The role of reverse osmosis in the production of green hydrogen

The water used to produce green hydrogen is processed in a water treatment device before it enters the electrolysis process. Contaminated water can interfere with this process, for example by polluting the electrolyser. In the treatment process, the principle of reverse osmosis is applied: the physical separation process filters the raw water by pushing it through a semi-permeable membrane. This removes all unwanted impurities. The purified water can be used in the electrolysis process.

...here you can find statistics on green hydrogen, electrolysis and demand:

In recent years, manufacturers of electrolyser around the world have recorded increasing demand and, as a result, an expansion of production capacities. In Germany, there is currently an electrolysis capacity fed by renewable energies for the production of green hydrogen of around 30 megawatts. In a study, the National Organisation Hydrogen and Fuel Cell Technology (NOW) assumes an increase in capacity of up to 275 gigawatts by 2050. Accordingly, the demand for water treatment plants would increase.

https://hydrogencouncil.com/wp-content/uploads/2021/02/Hydrogen-Insights-2021.pdf