Yesterday, in Mark's post about new technology that could one day generate power from slow moving currents in rivers and oceans, commenter SamSam wondered whether "any weird and new generators ever get out of the lab and start providing meaningful amounts of power?" It's a fair question, and I think a lot more technologies are announced than do (or ever will) make it to market. Partly, that's just the nature of invention. Partly, it has to do with the fact that it takes a long time to develop this stuff and we're still kind of at the beginning of the alternative generation industry. But sometimes, the crazy ideas do work, at least well enough to move out of the lab and into beta-testing. For instance, today, Norway's state-owned utility opened a prototype generator that produces electricity via osmosis.
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. 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 is very small--it only produces about a coffee-pot's worth of electricity--but if the kinks with the membrane can be worked out at this small scale, the utility could have a full-scale plant powering 30,000 homes by 2015. Also, I have to give a shoutout to the Norwegians for not claiming that their osmosis-based generator will magically solve the world's energy problems--instead describing it as part of a mix of different technologies that, together, could make a difference.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.