Wind power’s factor of unpredictability

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Is wind blowing us off course?

There’s been a lot in the Manx media about wind energy in the last few months, and rightly so.

We’re burdened with the infrastructure costs of the MEA power station in Pulrose, which are going to take a generation or more to pay off and the government can’t continue to shield us from the full effect of that forever.

While it looks likely at the moment that gas supplies will hold up for that time, they will run out one day, and market forces are going to make them much more expensive as time goes on. What’s worse, burning gas makes CO2, and this is beginning to affect our planet’s climate.

So what’s wrong with using the wind?

Nothing, provided that we accept the realities of the Isle of Man’s unique situation.

To start with, we have to look at our motive for using wind power. It can’t be to save money in the short term, because wind power is much more expensive to produce.

We’d end up spending money rather than saving it, and we still need to pay off the bill for the existing power station.

In the long term that may not matter, because fossil fuels will rise in price, but we have to accept that wind power is unlikely to save us any money during the lifespan of the wind turbines. What about saving materials? Well, most of the materials used are not recyclable, so while we save fuel we use up a lot of other stuff that will have to be thrown away when the wind turbines wear out.

It’s not obvious that we will end up using less CO2 either. For obvious reasons, wind turbines have to be built in windy places, and being huge structures they need substantial concrete foundations.

Producing thousands of tonnes of concrete also makes thousands of tonnes of CO2. It would take large quantities of diesel fuel to transport these building materials through Manx lanes that would need widening and reinforcing in places.

The remote sites where they are to be built would need access roads and hard standing. All this for something with a typical design lifetime of 20 years.

In his recent letter ffinlo Costain wrote under the headline ‘Wind farm remains on course for 2015’, but he was careful not to state the exact course.

You don’t need to be a sailor to know that the wind doesn’t blow all the time, and that sometimes it blows too hard. A small change in wind speed can also have a big effect on the power that a wind turbine produces.

Because we don’t know exactly how fast the wind is going to blow at any time, we can’t know how much electricity we’re going to get, and that’s a big problem. The electricity network needs to have just the right amount of power available at any moment, and wind power can’t guarantee that.

If we try to supply all our electricity from the wind, there will be calm winter days when we need lots of power and none is produced, and nights with huge amounts of power available at 3am when it’s not needed.

This unpredictability has to be compensated for somehow, and for now the only way to do it is by using our fossil fuel power stations.

When the wind slackens, fossil fuel takes the strain; when the wind picks up, fossil fuel can be burnt more slowly. At least that way we’re burning less fuel overall, right?

Sadly, it’s not that simple. Those power stations don’t take kindly to being constantly tweaked in this way. They need more maintenance and – guess what? – they use more fuel. We could end up saving much less carbon than we think.

So, am I against wind power? Absolutely not, but we need to address the variable and unpredictable nature of wind generation. If it’s not windy here, it’s probably windy somewhere else, so we need to network over large distances, maybe hundreds of miles, to share the resource.

That’s not possible on an island like ours, partly because our one interconnector cable with the UK was never designed for this job.

We don’t have the luxury of being on a large national or international power network that can absorb the fluctuating power output from wind generation. Remember, too, that nobody wants a wind turbine near them – we’re talking about a dozen or more huge machines, each over 400ft tall with blades more than 150 feet long.

The solution found by many countries, even continental ones like the US, is to go offshore. Like it or not, we’re going to have wind turbines off our coasts, outside our territorial waters.

The technology is improving all the time and the costs are slowly coming down. The logistic support to build and maintain them already exists and electricity networks are being put in place to handle the power coming from them.

From a technical point of view it wouldn’t be difficult to connect to those networks, although I accept that there may be commercial or political issues.

Manx territorial waters are much more extensive than our land area, offering plenty of space for wind farms. What’s more, we have some of the best waters around the British Isles for tidal flow generation, and opportunities for using wave power.

We need to set course out to sea, to make use of the proven technology that is already being installed nearby, and to research the potential of the tides and waves. Going for land-based wind farms will take us on to the rocks.


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