NEW YORK – Historically a dark horse, green hydrogen energy has received renewed attention among global policy-makers and energy experts as a potential driver of net zero emissions. This is in large part because of significant advances in enabling technologies along with government subsidies and industrial policies supporting its research and development (e.g. more than €5 billion approved by the European Commission and $9.5 billion in the US Inflation Reduction Act).

Emissions-free green hydrogen uses clean electricity from renewable energy sources, including solar, wind, geothermal and hydropower, to separate hydrogen from water in a process known as electrolysis. According to The Economist, the element is not a primary source of energy like fossil fuels, but an energy carrier like electricity. The article also notes that: “There is no natural source of hydrogen, and most of it is bound up in molecules like fossil fuels, biomass, and water.”

Thermodynamics dictates that making hydrogen from one of these molecular structures requires more energy input than the final output of hydrogen power. Hence, the processes used are currently limited to chemically altering hydrogen by drawing in other elements on the periodic table to produce steel and cement, fuel for rocket engines, explosives, and to refine ammonia for fertilizers. It is cost-effective for these specific manufacturing and industrial processes requiring higher temperatures than conventional electrical power sources. In short, clean hydrogen will require extraordinary breakthroughs in innovative technologies if it is to achieve its stated goal of generating emissions-free electricity to the masses.

This is not to dismiss the progress made since the world last took a stab at hydrogen in the 2000s. The source of energy determines where it lies on the hydrogen colour palette. Green hydrogen is created, as we have seen, using emissions-free energy. The lower costs of generating solar and wind power today may enable the commercial scaling-up of green hydrogen production and its corresponding supply chain. Conversely, grey hydrogen, representing 95% of what the world uses today, produces energy using fossil fuels that release carbon dioxide into the atmosphere. Its close cousin, blue hydrogen, comes from natural gas; its carbon emissions are sequestered underground using carbon-capturing methods, rather than being released into the air.

Taken together, they provide options that can complement the strengths and weaknesses of other energy sources such as the inherently intermittent nature of solar and wind power. Hydrogen is just one of many arrows in a diversified energy quiver battling global warming and increasing carbon capture.

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