First osmosis power plant goes on stream in Norway

Sited on the banks of the Oslo fjord in southern Norway, it generates electricity using the natural process that keeps plants standing upright and the cells of our own bodies swollen, rigid and hydrated.

Osmosis occurs wherever two water solutions of different concentrations meet at a semi-permeable membrane. The spontaneous passage of water from dilute to concentrated solutions through the membrane generates a pressure difference that can be harnessed to generate power.

"The potential is huge," said Terje Riis-Johansen, the Norwegian minister for petroleum and energy, speaking at the new plant's opening ceremony in Tofte, near Oslo, on Tuesday.

Statkraft, the renewable-energy giant running the project, estimates the total global potential of osmotic power to be around 1700 terawatt-hours per year – about 10 per cent of the world's current electricity consumption.