What stops these turbines from turning? You guessed it: wind!

Chris Donegan • Published 26 Jan 2012 13:00 0 Comments

Share this

Windmills adorn the skyline on the road between Ederney and Lack.

As the storms raged across Fermanagh at the beginning of the month and you cowered under the kitchen table there was only one thought running through your mind: Those wind farms must be milking it.

You may have imagined those huge turbines on the hill whizzing around like an aircraft propeller, generating enough environmentally friendly green electricity to light up half the country.

You may even have defiantly raised two fingers to Venezuelan president Hugo Charvas and his friends in OPEC, the Organisation of the Petroleum Exporting Countries' cartel, and shouted: "Tiocfaidh ár lá."

You may have been a bit premature.

Our day may well indeed come but it hasn't arrived just yet. We haven't reached the stage where Fermanagh is self-sufficient in renewable wind energy, never mind achieving the industry's dream of the county being an energy exporter. That will be the day when we all sport designer sunglasses and drive electric powered Toyota Land Cruisers around the sand dunes of Rossnowlagh.

Until then we are still dependent on oil.

So humblest apologies Mr. Charvas and Co.

Indeed we may be on our knees grovelling to the oil despots for longer than we would have wished.

If you lived near a wind farm and had picked up the courage to crawl out from under table at the peak of the storm, what would you have seen? You might have expected to see those turbines churning out enough gigawatts of electricity to sent Marty McFly and Doc Brown racing "Back to the Future" in their DeLorean sports car. But you would have been in for bit of a shock.

Because what stops a wind turbine dead in its tracks?

You guessed it. Strong winds. Gale force winds to be precise.

I'm not winding you up.

When storms raged across England and Scotland at the end of last year many wind farms shuddered to a halt. As the old fossil fuel power stations stepped in to save the day by ramping up their output, finger waving oil men and those frackers from the shale gas industry were knocking each other over in the rush to tell us wind energy was only so much hot air and couldn't deliver when it counted. A photograph of a turbine on fire at the height of the storm was used to illustrate a number of obituaries on the industry.

However, like our profane gesticulations at Hugo and Co., talk of wind energy's demise was premature. What the melt down did was generate debate.

According to the Government's Department of Energy and Climate Change: "Wind will be a key component in meeting the United Kingdom's 2020 target for energy from renewable sources, and onshore wind could deliver around 15 per cent of the total. The wind industry can be a key player in creating the investment, exports and jobs we need for a return to economic prosperity."

However, it admitted: "No individual technology will provide the silver bullet - our energy mix will have to become increasingly diverse. As part of that mix, onshore wind will have an important role to play as one of the most cost-effective and proven renewable energy technologies."

Airtricity is the biggest renewable energy generator in Ireland and owns the Tappaghan wind farm at Lack in North Fermanagh.

A company spokesman said: "Tappaghan wind farm produces around 75 million kilowatt hours of electricity each year, enough to power approximately 16,000 homes.

"The green energy produced at Tappaghan wind farm results in reductions of harmful carbon dioxide emissions of 32,200 tonnes each year," he added.

According to the Irish Wind Energy Association, Fermanagh's wind farms at Tappaghan, Callagheen near Belleek and Slieve Rushen at Derrylin, can generate up to 95 megawatts of electricity.

The Airtricity spokesman explained: "A modern wind turbine produces electricity 70 to 85 per cent of the time, generating different outputs depending on wind speed. Over the course of a year, it is likely to generate about 30 to 35 per cent of the theoretical maximum output. This is known as its load factor."

Under ideal conditions that load factor would increase to 35 to 40 per cent.

"Ideal conditions would include winds at of 25 miles per hour and slightly damp air," said the spokesman.

The air in Fermanagh is often more than slightly damp and sometimes breaks that speed limit.

"Wind turbines start operating at wind speeds of around 10 miles an hour and reach maximum power output at around 33 miles per hour. At very high wind speeds, for example Gale Force 9 winds of over 50 miles per hour, wind turbines automatically shut down," explained the spokesman.

Electronic monitors at the wind farms warn Airtricity staff of severe weather and when the wind speed drops back below 50mph for more than 10 minutes the turbines start up again automatically.

"During the recent severe winds, the power lost at Tappaghan wind farm was minimal - a couple of hours," explained the Airtricity spokesman.

In the event of it losing power from a wind farm, Airtricity can make up the shortfall by buying it from the Single Electricity Market, a central hub into which all generators feed their supply.

As to the future: "Airtricity has not undertaken specific research on the long-term impact of climate change on wind generation."

On the subject of climate change it said it was committed to reducing the carbon dioxide of electricity produced at power stations in which it is involved by 50 per cent by 2020.

"The United Kingdom and Ireland now have legally binding climate change and renewable energy targets, and this means that the way in which we produce electricity must change: power stations which produce large amounts of carbon emissions, like coal and gas, will have to gradually be replaced by those which produce very few, such as renewables.

"Fortuitously, Northern Ireland is endowed with one of the best renewable energy resources in Europe - wind," said the spokesman.

"Wind power is currently one of the most developed, cost-effective and scaleable renewable electricity technologies, with the United Kingdom and Ireland having the largest wind resource in Europe. For these reasons, wind power is expected to be the leading technology for the decarbonisation of the power sector in the medium to long term," he stated.

Airtricity's parent company SSE (Scottish and Southern Energy) announced this month that it has reached a significant milestone of more than one gigawatt of onshore wind farm capacity in operation for the first time - enough to power 800,000 homes for a year. The company has 30 operational onshore wind farms with another 48 wind farm projects in progress.

"Typically, SSE contributes over £225,000 annually from its Tappaghan wind farm to the local County Fermanagh economy through a combination of landowner payments, county council commercial rate payments, and community fund contributions. We estimate that over the typical 25 year lifetime of Tappaghan wind farm, SSE will contribute around £5.7 million in local contributions and payments and as such, Tappaghan is a major current and future net contributor to the County Fermanagh economy," said the Airtricity spokesman.

This article appeared in Impartial Reporter 26 Jan 12

Return to the main index, get more from this section or browse our News archives.