Researchers have built a kilowatt-scale pilot plant that can produce both green hydrogen and heat using solar energy
The solar-to-hydrogen plant is the largest constructed to date, and produces about half a kilogram of hydrogen in 8 hours, which amounts to a little over 2 kilowatts of equivalent output power.
“We have cracked the 1-kW ceiling for the production of solar hydrogen,” says Sophia Haussener, a professor of renewable energy science and engineering at the Swiss Federal Institute of Technology (EPFL) in Lausanne. “With half a kilogram of hydrogen you can drive a car for about 100 miles [160 kilometers]. Or you can use it in a fuel cell to produce electricity and satisfy about half the electricity needs of a four-person household a day.”
About 95 percent of the hydrogen used in the world today—mainly for producing fertilizers and other chemicals or for oil refining—is made by cracking natural gas, which produces carbon dioxide in the process. But hydrogen also holds tremendous promise as a fuel for airplanes and ships, for heating homes, and for producing electricity.
To be a sustainable fuel, though, hydrogen needs to be made using renewable energy or nuclear power with minimal emissions. This idea of green hydrogen is now picking up speed around the world. It is the centerpiece of Australia’s plans to decarbonize its economy, for instance.
One of the most sustainable ways to make hydrogen is to use solar energy to split water into hydrogen and oxygen. This can be done using photoelectrochemical (PEC) systems that combine a photovoltaic device and an electrolyzer device. The PV device absorbs sunlight and generates electricity that drives the electrolytic splitting of water. “You don’t have to design and pay for two separate systems,” Haussener says. “It’s one single integrated system, so ultimately there’s a cost advantage.” …. read more research at https://www.epfl.ch/en/