Policymakers and industry say the Midwest Hydrogen Hub will create green jobs and slash emissions, but environmentalists see a ploy to keep fossil fuels in use.

To make hydrogen, electricity is used to split hydrogen molecules from water. But this process is energy intensive, and where that energy comes from makes climate advocates question the “clean” branding.

Hydrogen production is color-coded based on the energy source used to produce it. Green hydrogen, for example, denotes that the power comes from renewables, like solar or wind. Pink hydrogen sources its power from nuclear energy. Blue hydrogen comes from natural gas and then traps emissions using carbon capture. When it comes to defining “clean hydrogen,” environmental advocates want to draw the line at green. But according to Banwart, the Midwest Hydrogen Hub will count all three as carbon-cutting options.

The vast majority of hydrogen manufactured in the United States today is produced with natural gas. Advocates say that anything that keeps fossil fuels online — including natural gas — isn’t clean.