Learning Through Osmosis (Power)

Next week begins international deliberations in Copenhagen, Denmark. The topic: how to move forward with on a multi-national framework to curb climate change.

At the meeting Prez Obama is expected pledge to cut US greenhouse gas emissions 17% on a 2005 base by 2020. (The EU has pledged to cut at least 20% by 2020 on that base.)  In doing so, Obama-san is going out on a limb, as Congress is still months away from passing a climate bill.

Expect more than the usual climate hoopla & hand wringing as America’s scientists and leading businessmen (& women) argue for a commitment for a climate-friendly economy and dinosaur energy interest wind up Toys for F.U.D. One favorite of the Fear, Uncertainty and Doubt Crowd is America’s lack of renewables (when in fact it likely leads the world in renewable energy resources). It is always welcome, then, when news of new, bountiful sources of clean power make strides towards commercialization. (It’s less welcome, when, as happens all too often these days, the news comes from abroad).

Here’s tell of one source of renewable power you’ve likely not heard a lot about: osmotic power!

TOFTE, Norway (Reuters) – Norway opened on Tuesday the world’s first osmotic power plant, which produces emissions-free electricity by mixing fresh water and sea water through a special membrane.

State-owned utility Statkraft’s prototype plant, which for now will produce a tiny 2-4 kilowatts of power or enough to run a coffee machine, will enable Statkraft to test and develop the technology needed to drive down production costs.

The plant is driven by osmosis that naturally draws fresh water across a membrane and toward the seawater side. This creates higher pressure on the sea water side, driving a turbine and producing electricity.

“While salt might not save the world alone, we believe osmotic power will be an interesting part of the renewable energy mix of the future,” Statkraft Chief Executive Baard Mikkelsen told reporters.

…

The main issue is to improve the efficiency of the membrane from around 1 watt per square meter now to some 5 watts, which Statkraft says would make osmotic power costs comparable to those from other renewable sources.

The prototype, on the Oslo fjord and about 60 km (40 miles) south of the Norwegian capital, has about 2,000 square meters of membrane.

Future full-scale plants producing 25 MW of electricity, enough to provide power for 30,000 European households, would be as large as a football stadium and require some 5 million square meters of membrane, Statkraft said.

Once new membrane “architecture” is solved, Statkraft believes the global production capacity for osmotic energy could amount to 1,600-1,700 TWh annually, or about half of the European Union’s total electricity demand.

This is a particularly interesting source of energy for at least two reasons 1) places where fresh water meets salt water tend to be close to large population centers (e.g. the entire Atlantic seaboard) and 2) power of this sort would behave more like “baseload” resources such as nuclear or coal, in that they could generate power 24-7, as opposed to solar or wind, which, at least locally, are intermittent.

Another promising tool for meeting the domestic and international commitments to combat climate change inevitable in our nation’s future. The question that remains: will we lead or follow?