Friday, September 5, 2008

Athwart the thawt


Diagram from the Guardian article here.

Another new sustainable technology bulletin. This one is a new configuration for underwater tidal-flow turbines. Looks like a push-lawnmower.

The transverse horizontal axis water turbine or THAWT for short. Gives a projected 12 MW from an installation using a fraction of the concrete and steel of a standard wind turbine, or the newer marine turbines with the same horizontal-axis-and-airfoil configuration.

Of course, we will have to build one and see if it works. The fun part.

And we will need materials science and engineering capable of withstanding the corrosion and pressure.

Funny, though, how all these experimental configurations use the same Newtonian physics and fail to add much to our lexicon of engineering, beyond reconfiguration of axis and airfoil.

Somehow I find that reassuring. I learned this particular physics and engineering myself three decades ago as an RAF "fitter" trainee. Those months in the classrooms and shops at Number One Technical Traning School, RAF Halton, have stood me in incredibly good stead for so many new things in my life. I definitely owe a big professional debt to the men of that program. Even though the instructors were all b.....ds and the drill sergeants hated my skinny sproggy untidy guts. Still, the high pressure meant that the lessons stuck well. In 1978 there remained a 1940s Battle of Britain, shoulders to the wheel, feel to the ground crew training courses, and some of the more elderly instructors, the flight sergeants and chief techs, had actually been around in those stirring times. They could be tough teachers though. The toughest.

But less nostalgia. Back to task.

The nice thing about the tide is it happens twice a day, every day. With our current soggy, hurricane remnant weather from the south, it hasn't been windy here in Maine for quite a few hours and days. (A fact that our wind turbine crews on Freedom Ridge are probably happy with, since wind is actually a hazard in the construction phase.)

Springs and neeps will make for similar back-up capacity restrictions to those found in wind energy development, however, and a similar build-out percentage at some fraction of total need. With wind turbines this is posited as around 20%, but the Dutch and Danes feel they might be able to do better.

Still, this new technology, if it works and is cost-effective as the authors suggest, ought to be a good one to try in Maine.

Keeping track of R&D in sustainability tech is hard. There's so many areas to keep up with. If I had a job as a specialist, I could just delve into one small patch, hoe my own row, and reap the harvest.

That wouldn't do my students very much good though. At this sage, knowing the basic principles and a little bit about each kind and configuration of renewable energy device is best. Actually betting on winners and losers is a job for the market, or occasionally for government, and particularly for chancy young dudes in suits and flash cars with (generally someone else's) money to burn, not for grey-bearded old lags like me.

I just read the news and tech papers and call it as I see it.

Caveat emptor.

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