Hydrogen has potential as a clean fuel, depending on how itâ€™s produced.
Hydrogen fuel burns clean, so it has potential as a low-carbon energy sourceâ€”depending on how itâ€™s made.
Today, most hydrogen is known as â€śgrayâ€ť hydrogen. Itâ€™s derived from natural gas using an energy-intensive process that emits a lot of carbon dioxide.
â€śBlueâ€ť hydrogen is sometimes touted as a clean alternative. Itâ€™s essentially the same as gray hydrogen, but the carbon dioxide emissions are captured during production, so theyâ€™re kept out of the atmosphere.
But Mark Jacobson, a professor of civil and environmental engineering at Stanford, warns that blue hydrogen is not really a climate-friendly option. Thatâ€™s partly because it still relies on natural gas, and producing and piping natural gas is a major source of climate-warming methane leaks. Jacobson says there is a better way to make hydrogen fuel.
â€śThe easiest way to produce hydrogen is to pass electricity through water,â€ť he says. â€śAnd if you generate the electricity with clean renewable energy like wind or solar power, then the whole process of producing the hydrogen is clean, and thatâ€™s called â€śgreenâ€™ hydrogen.â€ť
As solar and wind power get cheaper, so will the cost of green hydrogen. So, Jacobson says, itâ€™s a more promising path forward than gray or blue.
Reporting credit: Sarah Kennedy/ChavoBartDigital Media, and Diana Madson. Yaleclimateconnections.org.