NORWAY’S OCEAN OSMOSIS PLAY

Power of osmosis used to deliver eco-friendly energy; A Norwegian firm is testing a renewable and emission-free source of energy that harnesses the power of water through osmosis
Gwladys Fouche, 25 November 2009 (UK Guardian)

"The world's first test plant to harness osmotic power, a new emission-free source of energy, opened…in Norway. Nestled amid pine-covered hills on the banks of the Oslo fjord, 60km south of the Norwegian capital, the facility will exploit the energy produced when fresh water meets seawater.

"Statkraft, the Norwegian energy firm behind the test plant, says osmotic power could produce up to 1,600–1,700 terawatt hours worldwide – the equivalent of half of the energy generated in the EU today…"

click thru for a complete Statkraft presentation

"Statkraft says osmotic power would be especially suited for generating electricity for large cities…[situated where large rivers flow into the sea and therefore not needing new transmission]…[A] commercial [25 megawatt] plant would be…[the size of a football field]…[An] osmotic plant could [however] have the same environmental impact [on biodiversity] as a hydropower facility…[so the right site is crucial]…

"The new technology is based on the principle of osmosis, the diffusion of water through a semi-permeable membrane, which is how plants draw water from the soil…[F]resh water and salt water is guided into separate chambers, divided by an artificial membrane. When the fresh and seawater meet on either side of the membrane, the fresh water is drawn towards the seawater. The flow puts pressure on the seawater side, and that pressure can be used to drive a turbine, producing electricity."

click thru for a complete Statkraft presentation

"The two-storey, tennis-court-size [pilot] plant, situated next to a pulp mill, will generate little power…There is no river at the site…so Statkraft will use the water from a nearby lake piped by the pulp mill…The company hopes to launch the first commercial plant between 2015 and 2020 – if everything goes to plan.

"The challenges are many. First is the price…[S]ince it is a new technology, osmotic power is expensive to run…Another challenge is technical. The key to the technology is the membrane, but Statkraft says it needs to be made five times more efficient than it is today. Yet another issue is developing the business, with Statkraft looking to find business partners, such as membrane manufacturers and utility companies…[Other companies and NASA are] looking into osmotic power…"