Power-to-X (PtX) is an umbrella term for technologies that convert renewable electricity — mainly from wind and solar — into various energy carriers or products such as fuels, chemicals, or heat. The “X” stands for the target product.
Renewable electricity is widely used to sustainably power a wide range of applications, including electrical devices, vehicles, and industrial processes, but it can also be converted into products like synthetic fuels, chemical feedstocks, or heat, providing a flexible solution to reduce emissions in sectors where direct electrification is not practical.
How?
Through Power-to-X (PtX). These technologies convert renewable electricity into usable outputs that can be stored, transported, or used in energy-intensive industries. PtX provides a practical link between variable renewable energy and applications that require stable, high-density energy or specific molecules.
What Are the Key Ingredients of PtX?
Most PtX pathways rely on the same critical components, which enable the transformation of renewable electricity into energy-based products and feedstocks.
Renewable Electricity
At the core of PtX is renewable electricity — from sources like wind, solar, or hydropower. It serves as the primary energy input to produce fuels, chemicals, or other valuable outputs. While PtX technologies can technically run on any electricity source, their climate benefits depend on renewable power; if powered by fossil-based electricity, the process can lead to high emissions and lose its sustainability value.
Water (H₂O)
Through electrolysis — powered by renewable electricity — water is split into hydrogen (H₂) and oxygen (O₂). Electrolysis is an electrochemical process that uses electricity to separate water molecules into their component elements. The resulting hydrogen, often referred to as green hydrogen, is a key energy carrier and building block for most PtX pathways.
A Captured Molecule – such as Carbon Dioxide (CO₂) or Nitrogen (N₂)
CO₂ can be captured from industrial point sources or directly from the air, while nitrogen (N₂) is extracted from the atmosphere. These captured molecules are then combined with hydrogen to produce various products. For example, CO₂ is used to create eFuels, while N₂ is utilised in the production of eAmmonia.
Do All PtX Technologies Use Electrolysis?
Electrolysis is essential to many — but not all — PtX pathways. For example, Power-to-Heat directly converts renewable electricity into usable heat without chemical conversion, making it a practical option for replacing fossil-based heating in industrial processes, buildings, and even district heating networks. This demonstrates PtX’s versatility: it can involve both the creation of new energy carriers and the direct application of renewable power in sectors that are otherwise difficult to electrify.
Types of PtX Technologies
The ‘X’ in Power-to-X refers to the wide range of end products created when renewable electricity is converted into something else — such as gases, liquids, heat, fuels, or chemicals. While the applications vary, the goal remains the same: turning clean electricity into valuable outputs for hard-to-electrify sectors.
Below are some of the most common PtX pathways in use or advancing in scale. As the field evolves, new applications may emerge across additional sectors and use cases.
- Power-to-Hydrogen (PtH / PtH₂)
PtH uses renewable electricity to produce green hydrogen via electrolysis. This hydrogen can be used directly — for instance, in fuel cells or industrial processes — or as a feedstock in other PtX pathways, including synthetic fuels, ammonia, and chemicals. - Power-to-Liquid (PtL)
PtL enables the production of synthetic liquid fuels like eMethanol, eDiesel, and eKerosene. These fuels are drop-in ready for hard-to-abate sectors like shipping and aviation. - Power-to-Gas (PtG)
PtG produces gaseous fuels such as eMethane which can be injected into existing gas grids, used for industrial heating, or power heavy transport — offering a lower-emission alternative to fossil gas. - Power-to-Ammonia (PtA)
PtA enables low-emission eAmmonia production, primarily for use in fertilisers. As conventional ammonia synthesis is one of the most carbon-intensive chemical processes today, decarbonising this sector is crucial. - Power-to-Chemicals (PtChem)
PtChem offers sustainable alternatives to fossil-based feedstocks in chemical manufacturing. This enables the production of key industrial chemicals, such as ePolyethylene, for use in pharmaceuticals, plastics, and agriculture.
While the above categories are based on the type of product created, PtX technologies can also be grouped by their end use — for example, whether they serve transport, power generation, or heating. Below are examples of such end-use centric pathways.
- Power-to-Mobility (PtM)
PtM supports decarbonised transport by supplying renewable fuels — such as green hydrogen or eFuels — for use in road vehicles, shipping, and aviation. These fuels can often be used in existing engines or fuel cells, with minimal infrastructure changes.
- Power-to-Power (PtP)
PtP refers to converting stored energy — typically in the form of hydrogen or synthetic fuels — back into electricity. This is crucial for balancing the grid and ensuring electricity supply when wind or solar generation is low.
- Power-to-Heat (PtHeat)
PtHeat enables the direct use of renewable electricity for industrial or residential heating. Technologies like heat pumps and electrode boilers can replace fossil-based heating systems, helping reduce emissions from high-temperature processes, buildings, and district heating systems.
Power-to-X (PtX) technologies can be applied across a wide range of sectors.
These include:
- Mobility (shipping, aviation, heavy road transport)
- Industry (steel, chemicals, plastics)
- Heating (district and building heating)
- Agriculture (fertiliser production)
- Energy (power generation, grid balancing, re-electrification).
What Makes PtX Technologies Sustainable?
For PtX technologies to be considered sustainable, they must meet the following criteria:
Renewable Electricity
The process must be powered by electricity from renewable sources, such as wind, solar, or hydropower, ensuring that the carbon footprint of the final products remains low.
Carbon Capture
To create a truly circular process, captured CO₂ must be utilised effectively. For fuels and chemicals, this means the incorporated CO₂ is typically released back into the atmosphere when those products are used. However, if this CO₂ originally comes from captured sources — such as biogenic emissions or industrial point sources — then the amount of CO₂ released during use is roughly equal to the amount captured. This balance results in a near-zero or net-zero CO₂ footprint, effectively closing the carbon loop by preventing additional CO₂ from entering the atmosphere.
Energy Efficiency
The energy efficiency of PtX technology must be high enough to provide a viable alternative to fossil fuels, making the process both economically and environmentally beneficial.
Infrastructure Integration
PtX products must be compatible with existing infrastructure — such as gas grids or transportation fleets — allowing for scalability and seamless adoption in real-world applications.
Lifecycle Impact
Beyond energy efficiency, the entire lifecycle impact of PtX technologies, from raw material extraction to end-of-life disposal, should be considered to assess the overall sustainability of the technology.
