Planned electrolyzer installations that use electricity to produce hydrogen from water, if built, would expand capacity in the United States from 116 megawatts (MW) of current capacity to 4,524 MW, according to information collected by the US Department of Energy’s Hydrogen Program Record. If all the planned projects are implemented, annual US production of hydrogen through electrolysis could total about 0.72 million metric tons (MMmt) compared with the current 10 MMmt of hydrogen currently produced from fossil fuels and as a byproduct from other industrial sources, according to the US Energy Information Administration (EIA).

Electrolyzers that meet a threshold for low carbon intensity could qualify for a production tax credit if developers begin construction by 2033. Hydrogen is traditionally separated out of hydrocarbons, such as natural gas and coal, through a process known as steam methane reforming (SMR). The 10 MMmt of hydrogen produced annually in the United States is almost completely supplied by SMRs or produced as byproduct hydrogen obtained from a chemical plant or other facility where hydrogen is not the main product.

EIA estimates current US SMR capacity totals 7.6 MMmt of hydrogen a year.

Electrolyzers produce hydrogen through electrolysis, a process that separates hydrogen from water using an electrical current, with oxygen as the only byproduct. Because SMRs use hydrocarbons as feedstock, their byproducts include carbon monoxide and carbon dioxide, which must be captured and sequestered to achieve net-zero emissions. Hydrogen produced by electrolyzers is considered carbon-neutral if the electricity consumed is generated from renewable resources.

According to the International Energy Agency (IEA), two types of electrolyzer technologies are currently commercially deployed, both of which require further improvements to stay competitive: Proton Exchange Membrane (PEM) and Alkaline. These technologies vary by construction cost, start-up times, and materials used to convert electricity to hydrogen. No matter the materials used, electrolyzers can leverage electricity generated from renewable resources.