Green Hydrogen: An untapped resource for heavy industry, transportation, and Europe’s reliance on foreign energy suppliers
Renewable hydrogen — which is commonly known as “green hydrogen” — carries a respectable value proposition. Not only does it offer all the benefits of renewable energy to stalled sectors like shipping, rail, aviation, and heavy industry, it could enable European countries to break free of their dependence on foreign energy suppliers.
What is green hydrogen and how is it produced?
Even a quick scan of the Periodic Table reveals the prominent role that hydrogen plays. As the first element on the list, it has the atomic number 1 — indicating the presence of one proton within the atomic nucleus. Yet, despite the fact that it is the most common substance in the universe, hydrogen does not exist in a “pure” form, but rather must be extracted from its compounds. Derived from the ancient Greek word húdōr (“water”) combined with the root -ghen (“to generate”), the literal meaning of hydrogen is “generator of water.”
For our purposes here, there are four main types of hydrogen that I want to discuss:
● Grey hydrogen is derived from a chemical process called “steam methane reforming,” which relies on the use of fossil fuels. Although the process is efficient and economical, it leaves a heavy carbon footprint in its wake.
● Blue hydrogen uses the same production method as gray, but, in the end, captures the CO2 through a process known as “carbon capture.” While the Carbon Capture, Utilization and Storage (CCUS) protocol mandates that producers set a minimum target of 90 percent capture, most independent organizations only capture a meager 60 percent.
● Green hydrogen is produced through electrolysis. Essentially, renewable sources of energy are used to split hydrogen and oxygen, thereby transforming electrical energy into chemical energy without producing carbon emissions. For this, water must come into contact with two electrodes (a positively charged anode and a negatively charged cathode). The electric current, which passes through the two electrodes, separates the molecules into H+ hydrogen ions and OH- hydroxide ions. After a reduction reaction occurs, the hydrogen ions acquire electrons and transform into hydrogen gas. To make the process as green as possible, the electron cell must be near a renewable energy plant to harness that type of electricity. Source: ENEL.