Power-to-X (PtX/P2X) Technologies for the energy transition: Power-to-X makes it possible to make electricity from the sun and wind storable and transportable.

What is power-to-X?

Solutions that make electricity from the sun and wind power storable are required on the path to climate neutrality. One way is to convert volatile generated electricity into chemical energy. The basis for this is the element hydrogen. Hydrogen can be produced through the electrolysis of water. When energy from renewable sources is used to split water into the elements oxygen and hydrogen, we speak of green hydrogen.

Power-to-X is essentially based on hydrogen, but goes beyond pure electrolysis and, above all, direct use of the gas. In order to accelerate the energy transition and the decarbonization of entire industrial sectors, P2X provides answers to exactly what the element hydrogen can be used for.

Distinction between different forms of energy

In the narrow sense, power-to-X means converting energy into another form. Here, a distinction can be made between the different forms of energy. Typical representatives are power-to-gas, power-to-heat, and power-to-liquid.

Power-to-heat (PtH/P2H)

Another representative in the field of application is called power-to-heat. This concept considers the conversion of electrical current into thermal energy, e.g., with the help of heat pumps or electric boilers. However, this concept is by no means similar to an electrically operated heating system. Rather, power-to-heat pursues the goal of converting excess energy from renewable sources in such a way that it becomes storable.

Power-to-liquid (PtL/P2L)

Power-to-liquid involves processes that can essentially be combined under the designation “e-fuels.” These include, for example, methanol and ammonia. The basic principle is to synthesize easily usable and transportable fuels using renewably produced hydrogen as well as CO₂ or nitrogen. Research has shown that ammonia, whose structural formula is NH₃, can play a key role as a green fuel. Compared to other energy sources such as liquid hydrogen and methanol, ammonia scores with comparatively low production costs. However, the high toxicity remains an issue.

Distinction between intended use

A further distinction can be made according to the intended use, although there is certainly some vagueness in the distinction here.

Power-to-ammonia, i.e., the synthesis of ammonia, belongs to the power-to-liquid range and the field of e-fuels. Ultimately, this intended use pursues the goal of converting renewable electricity into a chemical energy source to make it storable and transportable. Other typical terms include power-to-chemicals, power-to-fuel, and power-to-syngas.

Power-to-X is more than just hydrogen electrolysis

“Power-to-X is a holistic approach to converting renewable energy. We therefore go far beyond the mere storage of chemical energy,” explains Matthias Füller, Vice President VMM Process Industry at Phoenix Contact.

This conversion requires solutions at the system level for automation, electrification, and networking. You will find more information on how such systems based on standardized technology can look and where power-to-X from Phoenix Contact is already in use under the following link.