Hydrogen is the lightest element on the periodic table, but it’s really known for being the clean fuel that could solve a lot of climate headaches.
When it’s burned, hydrogen produces only water vapor. That’s an attractive proposition for industries such as steel makers, chemicals producers and aviation that need fuels but not the carbon footprint.
The key is to produce hydrogen without also producing carbon emissions. However, most of the hydrogen used by industries today comes from converting natural gas in a process that releases a lot of carbon dioxide: Some 900 million metric tons each year to be precise, according to the International Energy Agency. That matches the combined annual emissions of the U.K. and Indonesia.
Hydrogen will need to be made differently for it to become a viable climate solution. One option is to keep using fossil fuels in the production, and then capture and store the emissions. Another is to stop using coal and gas altogether. Instead, renewable energy sources could power machines that split hydrogen from water.
Currently, it’s much more expensive to produce the gas with renewables alone. But as the cost of green energy declines and manufacturing of the machines increases in the coming decades, renewable hydrogen could become a financially attractive fuel.