Wave Power Fails To Live Up To Promise

the_newsbeagle writes: One of the leading companies developing wave power devices, Ocean Power Technologies, has dramatically scaled down its ambitions. The company had planned to install the world's first commercial-scale wave farms off the coast of Australia and Oregon, but has now announced that it's ending those projects. Instead it will focus on developing next-gen devices. Apparently the economics of wave power just don't make sense yet.

Comments

When doing anything involving the ocean

[geekoid]

Take you expected costs, double it, then throw the piece of paper way because it's still useless.

Re:When doing anything involving the ocean

[Jane Q. Public]

When I was a child, we had a nice wood boat. A ChrisCraft. The finish was getting pretty weather-worn so my father took it to a guy who refinished boats to get it done. He specified brass screws, just like the original. The refinisher said, "Everybody uses stainless steel these days. They're just as good." My father reluctantly let him use the stainless steel screws.

The boat was moored by strong chains to a dock in the ocean. (You had to leave lots of play in the chains so the boat could ride up and down with the tide.) A few weeks later, by family got a call from the SeaBees. They had found the boat, dangling underwater by the chains holding it to the dock pilings.

The seawater had eaten the stainless steel screws right up. It only took a few weeks.

Re:When doing anything involving the ocean

[swb]

The original screws were probably bronze, not brass. Bronze has no appreciable zinc while brass contains a lot of zinc. Immersed in sea water, brass will dezincify and corrode.

Most marine raw water systems use bronze fittings for this reason.

Stainless isn't suitable for below the waterline applications because the chromium can't form a protective oxidization layer due to the lack of oxygen exposure.

Your boat would have sunk with brass or stainless screws.

sorry

[Charliemopps]

Moving parts = bad idea.
Moving parts in salt water?
Repairs under water?!?!
It's as simple as that.

Re:Too bad

[bluefoxlucid]

Ocean warming is a bigger opportunity. Jabbing a thermal collector into a volcanic vent, rolling it through a sterling engine as a cooling system, with the cold side submerged in the cold ocean.

A lot of new, green tech is ludicrous. People want solar farms in the desert because of all the arid heat and lack of clouds, but discount the fragile ecosystem. Wind farms take up much more space than nuclear plants for the same power output. Hydrogen is difficult to store without supercooling, and is only a storage scheme and not a generation scheme, and only operates at 50%-80% efficiency. Hydroelectric is an environmental disaster.

Direct heat applications from solar-thermal water heating are about the only thing that make sense. Their efficiency is high, and their cost is low. A small, 1.2 square meter collector provides 3000BTU/hr, about 85% of a kW; I can fit over 20 of these on my roof at a sun-receiving angle and spacing, giving over 65,000 BTU/hr average throughout the day. My roof can produce 19kW of heat output, while I only need 3kW to stay warm or cool--the AC breaker is 30A, providing about 3kW of cooling.

A hydronic coil off the water heater, an absorption cooler, or so on can harvest the heat collected by less than $2000 of tubes and a total of $3000 of equipment to provide for about $2500 annual air space and water heating and cooling in my house. Excess generated heat could theoretically drive a sterling engine to produce a small amount of electricity, but the investment for more tubes to generate a useful amount of electricity would be unjustifiable; I can buy 100% solar electricity for 12 cents per kWh.

Thus, in just over a year, I can recover my investment in solar water heating by incorporating space heating and cooling, assuming I was in the market for a new furnace and air conditioner anyway--the furnace would be an air handler with electric back-up, vastly cheaper than a new gas furnace, offsetting the expensive absorption chiller. A $900 pellet stove would serve as a back-up. Overall, the setup would save an immense amount of electricity and natural gas.