Emission-free hydrogen could, one day, entirely replace fossil fuels - and a start up believes it can make it accessible to all.

The system hoists 30 tonne “mobile masses” into the air using excess energy. When the need arises for the power, the mass descends.

Treating wastewater is a vital process, as it removes pathogens and protects the environment, however it comes at an environmental cost.

Researchers have developed prototype technology that can double the power harvested from ocean waves.