Ocean Kinetics - The Engineering Experts

Letters / Breezy, not windy!

It seems that some problems are destined never to be solved (Last fight over Viking Energy next month; SN, 26/11/14). Take, for instance, the case of the Lang Kames project, also known as the Viking wind farm.

Slightly more than six years after a private email exchange with one of the founders and main movers of Sustainable Shetland ended with me informing him that, in my opinion if he took a political rather than a technical tack in opposing that project, he’d fail (simply because Viking Energy would be better at ‘playing politics’ than he was), the whole wrangle is still on-going.

He duly went ahead and formed Sustainable Shetland anyway only a few weeks after that exchange finished; and now here we are, six years on from that time with yet another expensive ‘enquiry’ or ‘review’ of the situation.

Let me say at the outset that I’m not in the least bit opposed to the IDEA of wind farms – but that my experiences of correlating local wind speed regimes in several countries with a variety of wind turbine manufacturers’ own published data (usually in graph form) have shown in all cases that wind farms are a complete failure on a technical level, in that they can’t deliver the power that they’re supposed to be able to.

On that basis, I’m distrustful of everything I’ve heard about and seen of them, while ever-hopeful that they’ll all justify themselves one day in terms of anything other than money subsidies and ‘green’ fantasies.

Worse than that, the failure of wind farms in general is being disguised wilfully by the adroit use of emotional language, and by trading on the general technical ignorance of the populace at large.

For instance, one of the verbal ‘sleights-of-hand’ used with regard to weather conditions on Shetland is to describe the place as being ‘windy’.

In strict Beaufort-Scale terms, this appears to be a deliberate mis-statement, if not an outright lie – because the Beaufort Scale descriptions of air movement assigns magnitude numbers ranging all the way from flat calm (Force 0), to Light Air (Force 1), to Light Breeze (Force 2), through Gentle Breeze (F3), Moderate Breeze (F4), Fresh Breeze (F5) and Strong Breeze (F6) – when suddenly, and for just one band of wind velocities (Force 7), it’s described as High Wind or Gale before it moves on to Gale or Fresh Gale (F8), Strong Gale (F9), and Whole Gale or Storm (F10).

It may seem like a quibble to say that Shetland is breezy rather than windy – but the truth is that, for a place whose mean annual wind speed is a mere 12 mph (Force 3, Gentle Breeze), the only true description of Shetland’s weather is that of ‘breezy’ (qualified by ‘and not very, most of the time’).

Wind turbine designs generally haven’t reached a stage yet where anything but laughable quantities of energy can be generated in winds of only Force 3 intensity.

A quick look at the ‘power’ (energy) curves for the Vestas and Enercon turbines (in particular) will show up this truth immediately, in all cases; and since the information is in the public domain, just as is the Meteorological Office’s annual average wind speed data analysis for all UK postcodes, a simple (and most revealing) correlation of the two can made possible simply by displaying them side-by-side on two separate Internet Explorer windows.

Any discussion on how to increase the output of any given turbine would be speculative – because not even the turbine manufacturers have managed to do that yet – but increasing the available wind-generated torque (or ‘angular leverage’, which is the means to drive a heavily-loaded generator) and the speed at which the rotor turns would both have to figure in the evaluation.

Unfortunately, increases in either or both of those quantities would involve increasing the rate at which the air is cut by any given rotor; which inevitably multiplies the risks and dangers to bird life.

A cynic might argue that if a bird’s eyesight isn’t good enough to allow it to avoid a collision with a wind turbine blade, then maybe that bird has reached the point in its life where it can no longer successfully forage for food, and is possibly only days away from being unable to avoid being torn out of the air by a bonxie flying around on a ‘snack mission’. That’s for the naturalists to argue about and decide – it’s beyond me.

The latest almost-laudatory article in the SN yesterday concerning Viking Energy was headed by the following picture:

It shows an almost ‘Teletubbie-ish’ fantasy presentation of how the Lang Kames would be expected to look after the wind farm has been installed.

This can’t possibly be realistic: because it doesn’t show the Burn of Lunklet in permanent torrential flood after rainfall (as it will be when the pattern of hydrology on the Lang Kames has been destroyed forever); and it certainly doesn’t show the bog-burst and peat slippage that would result from the peat blanket having been pierced to allow turbine bases and roadways to be installed, and then not knitted back into one piece to keep it firmly in place (because no such technology exists yet).

Neither does it show the extent of inundation of places downstream of the Lang Kames, both north and south, where widespread flooding will destroy all of the property in its path.

I suppose I could observe that the relatively minor problem of possible closure of the A968 by landslide would be the council’s problem to clean up; but at a time when a number of schools are still facing closure, and when an article this week in this very newspaper states that Toft Pier can’t be repaired (both of which are because there’s no money to pay for the work to be done, due to past profligacy on the part of people who were well-paid and trusted to know better), I have to wonder at how the money will be found to keep that road open.

I shall continue to watch the progress of the Lang Kames Project with considerable interest – because, not only can I not see how it will ever make any money, or generate adequate amounts of electricity that would justify the construction of a mainland interconnector cable: I can’t see either how it could possibly reel-in enough investors to get it going – especially not when penny drops regarding the implications of the local average wind speed vs. the turbine energy curve information that I alluded to earlier on in this letter.

Philip Andrews
Unst

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