Osmotic Power has been kicking around for a while now, with researchers trying to make it cost-competitive--the biggest hurdle when you're trying to generate electricity by passing fresh water through a membrane into saltwater. Now, a new report from cleantech consultants Kachan & Co says that the potential of osmotic power is such that by 2030 it could generate enough electricity to meet 50% of Europe's demand. As the title above indicates, there's a lot of uncertainty when it comes to exploiting that potential.But first, for those scratching their head at the mention of osmotic power...
Baseload Power, Eventually...
There are two varieties of osmotic power: Reverse Electrodialysis and Pressure Retarded Osmosis. Though the technologies differ, they both generate power by harvesting the power created when saltwater and fresh water meet.
Both methods have trial- or pilot-scale power plants in operation, but these are a ways off from being able to be scaled to commercial level and a price that is anything near cost-competitive, with other renewable energy sources or fossil fuels sources alike.
Late last year Norway's Statkraft said their pilot plant (4 kW) had a membrane efficiency of less than 1 watt per square meter, which will increase to 2-3 watts/square meter after the plant has been running for a while. The break-even point is 5 watts/square meter.
All that aside, the big attraction of osmotic power is that, unlike other renewable energy sources, it is not intermittent, can be produced 24 hours a day and, as Kachan & Co. points out, "isn't dependent on large visible arrays of hardware in fields or on skylines."
Which isn't to say that a commercial osmotic power plant would be small or even medium sized. Statkraft envisions 25 MW plants being the size of a football stadium.
More Than Two Years Before Commercial Plants Viable
Back to the power potential... Kachan & Co. virtually reiterates figures that Statkraft has already released--osmotic power could produce up to 1,600-1,700 terrawatt-hours annually by 2030.
Dallas Kachan notes, "Some vendors claim we're only a year or two from commercial plants, but that feels ambitious. Our report finds there are still technical, permitting and regulatory hurdles. Yet the promise of osmotic power is significant, and an industry is beginning to emerge."