Thursday 13 April 2017

Solar-to-hydrogen efficiency record broken

The US National Renewable Energy Laboratory (NREL) has broken the world record for solar hydrogen production.

Scientists there managed to acheive a solar-to-hydrogen efficiency level of 16.2%, smashing the previous record of 14%.

The process uses photoelectrochemical (PEC) cells to split water and make hydrogen using sunlight as the only energy input.

The record-setting PEC cell represents a significant change from the original concept device developed at NREL in the 1990s.

It has undergone a number of signficant changes, including re-ordering the layer of chemicals inside the cell and adding extra layers of material to eliminate defects at the surface.

Minimising these defects improves efficiency and better protects the critical underlying layers from the corrosive electrolyte solution that degrades the semiconductor and limits the lifespan of the PEC cell.

Before the technology can be commercially viable, scientists say the cost of hydrogen production needs to fall below $2 (£1.60) per kilogram made.

Continued improvements in cell construction, efficiency and lifespan are needed to meet this target.

Scientists have developed a way to use sunlight to turn unprocessed biomass into clean hydrogen.