Power-to-X

Essentially, "turning electricity into something else.” Power-to-X is the umbrella term for both hydrogen electrolysis and a series of steps that can be added. For instance, when renewable hydrogen is combined with carbon, it can produce methanol, which in turn can be refined into other hydrocarbons. Or when combined with nitrogen — readily available as it constitutes about 80 percent of our atmosphere — it can be turned into ammonia, both a key component of fertilizers and potentially a carbon-free shipping fuel.

Hydrogen is the most abundant element in the universe. In its purest form, hydrogen is usually a gas – a colorless, odorless substance that can be burned to produce heat. It’s also one part of a water molecule. Unlike fossil fuels, hydrogen has no carbon in it and thus using it as a fuel to produce energy does not release carbon dioxide (CO2).

Hydrogen is not a new product. Today, hydrogen is used primarily by heavy industry. Globally, about 115 megatons (Mt) of hydrogen are used each year, mostly in oil refineries, for production of ammonia and methanol, and for other chemical and industrial processes. Modern day demand is almost exclusively met with hydrogen produced by "cracking" fossil fuels at a molecular level — and so, while using hydrogen does not add CO2 to the atmosphere, traditional methods of producing it do.

Green hydrogen, also referred to as renewable hydrogen, is produced by splitting water into hydrogen and oxygen using renewable electricity. The hydrogen is collected and used, while oxygen is released as the by-product if there is no need for it locally. The splitting process used is known as hydrogen electrolysis, a well-established technology which has been deployed commercially for decades around the world.

Fortunately, electrolysis — using renewable electricity to split water into hydrogen and oxygen — offers an alternative path to produce hydrogen with no greenhouse gases emitted. Costs of wind and solar generation have decreased over the past decade to the point where renewable energy is more affordable than power generated from coal, gas or nuclear. Because of this, green hydrogen is quickly emerging as a key component in a truly decarbonized economy and world. Replacing fossil-based hydrogen with green hydrogen in industrial processes, as well as using green hydrogen to replace fossil fuels in heavy transportation, would save huge amounts of carbon emissions and make a significant contribution to America’s climate targets.

Yes, hydrogen is safe if handled correctly. Industries have been using hydrogen in their processes for decades, so this is not a new technology or application. Hydrogen is a non-toxic gas at room temperature and atmospheric pressure. Hydrogen is explosive under certain conditions when mixed with air – similar to natural gas. Therefore, tried and tested international standards exist on how to design and monitor hydrogen installations.

In the carbon-heavy sectors of industry and transportation, there are at least three immediate uses for renewable hydrogen in the short term:

• Replacing the use of fossil-based hydrogen with renewable hydrogen. Many current industry practices such as refining petroleum, treating metals, producing fertilizer, and processing foods all use hydrogen.
• Providing industrial heat for manufacturing processes, such as steelmaking, which are difficult to electrify.
• Using renewable hydrogen as a fuel or component of other e-fuels for transportation including medium- to heavy-duty land transportation, shipping, and aviation. E-fuels include products like methanol, ammonia, or kerosene based on renewable hydrogen.