It is seen by many as the clean energy of the future. Billions of dollars from the bipartisan infrastructure bill have been teed up to fund it.
But a new peer-reviewed study on the climate effects of hydrogen, the most abundant substance in the universe, casts doubt on its role in tackling the greenhouse gas emissions that are the driver of catastrophic global warming.
The main stumbling block: Most hydrogen used today is extracted from natural gas in a process that requires a lot of energy and emits vast amounts of carbon dioxide. Producing natural gas also releases methane, a particularly potent greenhouse gas.
And while the natural gas industry has proposed capturing that carbon dioxide — creating what it promotes as emissions-free, “blue” hydrogen — even that fuel still emits more across its entire supply chain than simply burning natural gas, according to the paper, published Thursday in the Energy Science & Engineering journal by researchers from Cornell and Stanford Universities
To arrive at their conclusion, Dr. Howarth and Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford and director of its Atmosphere/Energy program, examined the life cycle greenhouse gas emissions of blue hydrogen. They accounted for both carbon dioxide emissions and the methane that leaks from wells and other equipment during natural gas production.
The researchers assumed that 3.5 percent of the gas drilled from the ground leaks into the atmosphere, an assumption that draws on mounting research that has found that drilling for natural gas emits far more methane than previously known.
They also took into account the natural gas required to power the carbon capture technology. In all, they found that the greenhouse gas footprint of blue hydrogen was more than 20 percent greater than burning natural gas or coal for heat. (Running the analysis at a far lower gas leak rate of 1.54 percent only reduced emissions slightly, and emissions from blue hydrogen still remained higher than from simply burning natural gas.)