Pelamis Power, the company putting large, snake-like devices off the coast of Portugal appears to be having money trouble. The company that owns them is, well, going bankrupt. Until Pelamis can find a new financial friend, it looks like they will have to wait on the sidelines.

It’s starting to look like ocean and wave power might just be one of those technologies that never really takes off; kind of the way algae looked after last week’s announcement that GreenFuel was closing shop. It’s frustrating, because when you look at the ocean you can’t help but thinking “Man! Why aren’t we tapping all that energy?”

The hard truth is: although it would be nice, it’s just technologically very difficult to build, operate and maintain these things at sea. Even Verdant Energy can’t seem to put turbines in New York’s East River yet. Granted, these are engineering challenges and they will eventually be overcome. But let’s not forget that even if we tapped all of our shores, it wouldn’t be that much. At a conference this year, Saul Griffith estimated the entire global tidal potential at 3.5 TW, which may sound like a lot, but is actually pretty low compared to other sources (he estimated global geothermal capacity, for example at 32 TW). So is wave power really worth the effort?

But there are those who are more optimistic, and see Pelamis’ failure simply as the inevitable consequence for an overambitious startup. This Green Inc. piece quotes one Robert Bedard of the Electric Power Research Institute (a think tank out in Palo Alto where scientists think about the future of electric power), who believes that PG&E and Ocean Power Technology have a chance to really succeed, as they have more money and experience.

Via Green Inc

Offshore power generation is usually thought to mean windpower (despite the fact that there is still none in the United States). But other means of extracting energy from near shore regions are being explored, as well. And a new variety of tidal power generation is one of the latest systems to be explored.

Developed by scientists at NASA's Jet Propulsion Laboratory, the new hydrokinetic system uses tidal turbines to create a high pressure fluid, rather than making electricity with each turbine. The high pressure fluid is driven to shore where the generating turbine is located.

One difficulty for engineers is that electrical cables are needed to go several miles (or more) from the generator to the shore where the power will be used. Undersea cables need to be more than just a couple of wires and have to be safe, even after rough treatment and exposure to ocean conditions. Seawater is very corrosive and that only adds to the need to protect the cabling and the other electrical components. Locating the generating facility on land helps reduce the complexity of the system, and keeps seawater and electricity segregated from each other.

Potentially, the system costs could be lower by using simpler pumping turbines rather than generating turbines in this configuration. Maintenance costs might well be lower, too, since there are no electrical systems that need to be maintained out in the water.

link: JPL site