Using sunlight, a Japanese professor has found a method of creating hydrogen for fuel cells that takes 50% less energy than a conventional process.

Clean-burning fuel cells convert hydrogen to energy and produce water as the only byproduct. Creating hydrogen, however, is an energy-intensive process.

Mainly, it’s created by passing an electrical current through water, separating oxygen and hydrogen through a process called electrolysis.

Hydrogen can also be created, however, through photodecomposition by exposing hydrogen sulfide to sunlight. Long in development, this process has now been shown by Tohoku University Professor Kazuyuki Toji to require 50% less energy than electrolysis.

Toji use a new catalyzer made of tiny particles of sulfated cadmium. He places this into a solution of hydrogen sulfide and exposes the mix to sunlight. A solution spread over one square meter can produce about seven litres of hydrogen per hour — 20 times greater than the amount that can be produced through electrolysis. Two-hundred square metres could power one household.

Toji will officially announce his findings, as well as perform a demonstration, at an October 16 symposium on environmental issues to be held at the National Science Museum in Tokyo.