Top-heavy marine device falls over, film at 11

[fivemack]

http://www.tridentenergy.co.uk/index.php

I don't quite understand how what these people are trying to do makes any kind of sense at all; their Web site looks like the write-up of a good A-level design technology project, and says in pieces dated February that they're about to start the test that clearly just failed to start in mid-September. The design seems to have a single guidance bearing taking all the sideways force of North Sea waves, held up on a remarkably flimsy-looking tower, and their prototype is made of eighty tons of steel and using four quite complicated linear generators to generate twenty measly kilowatts. I admit that I was slightly surprised that any marine engineers were involved in the endeavour at all.

What have I missed?

I'm sure it's unfair to compare the cost of tidal equipment to that of wind or solar; there's been, what, three orders of magnitude more money available for optimising wind and solar. But I can't help feeling there's a conclusion to draw from the fact that almost every story I read about wave power involves a wave-power demonstration, set up by a small company and producing less power than the smallest wind turbine Vestas will deign to sell, being destroyed by the wrath of Poseidon.

Comments

[nojay.livejournal.com]

The great thing about tidal and wave power is the density of the medium; it carries a lot of energy. The bad thing about trying to harvest tidal and wave power is the density of the medium as it contains a great deal of energy which the harvesting device has to resist in some manner in order to convert it to something useful (compressed air, electricity, flying monkeys, whatever).

[seawasp]

In a reasonable sea state, waves generate considerable energy. Turning that energy into electricity has some interesting hurdles and limitations, unfortunately. Why some of the designs I've seen are being used... I don't know. There's designs I'd use for temporary power (I'm actually in the process of writing a proposal for just that purpose), but something that's meant to last for any length of time in the ocean? That's major engineering, and not something to be approached lightly.

[htfb.livejournal.com]

It's certainly unfair to compare the cost of a first marine demonstrator, whose purpose is to prove the concept in a hostile environment, with any commercialised product at all. It has to stand in 25m of water and let people work on board, so it's going to be big---which means you've had to raise capital to build it, and therefore already had to convince people that your technology should scale to economic production at current levels of subsidy. So far, so sane.

And indeed the generator is serious engineering by serious engineers. I know (ref: private communication) that the bearings are one of the difficult and clever bits; the actual linear generator is very simple---and therefore potentially cheap and robust enough to make power economically.

You might read this embarrassing episode as a parable of the well-known weaknesses in this country's route for bringing inventions and basic research into commercial products: capture at too early a stage by the money-men from the technologists.

As I understand it (op cit.) much of the delay in launching the trial was caused by arguments over how to moor the rig. The engineers wanted to use a robust four-point mooring where the capitalists (who by now have a controlling interest) were wanting a two-point one. An independent report was commissioned and backed the engineers.

My guess would be that similar corner-cutting, which the engineers in this case couldn't head off, will have been responsible for the manner in which the rig was launched and for this catastrophe. Such a waste.

[pseudomonas.livejournal.com]

This is always the way with a proof-of-concept demo anything - they're intended to demonstrate one point, not to be useful in the real world. If they didn't have limitations they wouldn't be prototypes. It's a pity that the limitation in this case was quite so messy.

[arnhem.livejournal.com]

Surely the big problem with tidal energy harvesting is getting the power back to where you want to use it? [ similarly, to a lesser extent, with covering deserts with solar panels ].

On the other hand, if you've got an energy-intensive way of fixing atmospheric CO2, it doesn't really matter where you do it ...

[sonicdrift.livejournal.com]

Remind me on Thursday to explain in detail and at length, but basically the density of water is much greater and we get a predictable flow of it everyday.

In the mean time enjoy SeaGen, which is kinda cool even though it's basically a wind turbine under water:
http://www.marineturbines.com/