Re: Here be dragons...



Nick Temple-Fry wrote:



Thanks guys. I'm just praying that I haven't dropped a couple of noughts

from the sums! 


Well you could compare your results with the information in the
library section of the website. Which I'm sure, by now, you are
totally familiar with.

Fascinating, isn't it? They've built a prototype which has been running for a couple of years, but where is a summary of it's performance? Mostly the papers comprise a lengthy description of other means of harvesting energy, either wind or wave. Nowhere do they say specifically how the prototype is performing, but the nearest we get to a performance figure is obtained by lookong at 2 of their papers. One states that the average wave power for the prototype is 0.4kW.m, and yet their predictions for a "full size model" is based on a wave energy density of 36kW/m. Now that's a f*** of a big diference, and begs 3 questions: 1. is the figure realistic, 2. can we expect the performance to scale?, and 3. that's one hell of a jump up in size and consequential engineering complexity! Looking at another paper, the prototype annual output (mesured or predicted? it doesn't say) is 0.06GWh/year. Looks impressive, doesn't it, quoting numbers in terms of gigawatts? Unfortunately, as there are about 10,000 hours in a year, this translates to a mean output of 60kW (looks like my back of the envelope numbers weren't so far out!).
Another cause for suspicion is the monumentally stupid set of equations and accompanying graph in the Christensen 2005 paper. There is no explanation of where these expressions come from, what they mean, or what their relevance is to the price of fish fingers. Am I missing some sublime truth here?. Can anyone spot "power output" in the data? I certainly can't! Isn't it interesting how many of the experimental points lie on the zero line, although I've no idea as to what the axes mean.
I bet our political masters are seriously impressed, that journalists are gathering round claiming that this is the solutioon to all the worlds problems. Me? Just a congenital cynic, I'm afraid.




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