Key to this whole argument is security of supply
THEY'RE a thing of beauty, or a blot on the landscape. They help reduce bills, or drive prices up because of subsidies we pay. They're the solution to our energy crisis, or a barrier to reducing consumption.
Never has a technology been so polarising as wind energy.
The first windfarm was erected in Ballacorrick in Co Mayo in 1992, and it is still generating power today. By the end of this decade, there will be sufficient wind on the system to power more than three million homes, with more than 263 individual farms dotted across the country.
And like all large-scale infrastructure projects, the issue is rife with controversy. The Government, and developers, say we need renewable energy to hedge against future oil and gas price increases, to develop an indigenous supply and help meet climate change targets, where 16pc of all electricity must be produced from renewable sources by 2020.
Opponents say the turbines, which can be up to 180 metres high, are a blot on the landscape and don't benefit the host communities because the power is transmitted elsewhere. They impact on health and property values, and the only winners are the companies involved in their construction, they say.
But concerns about new forms of electricity generation becoming costly white elephants are nothing new.
In December 1924, William Hewat from the Businessmen's Party told the Dail the costs of developing the Ardnacrusha hydroelectric plant – at the time designed to serve the entire country's needs – were based on a "Dublin supply".
Conor Hogan from the Farmers Party added that judgment on the merits of the scheme should be "suspended" until it was proven that cheap power could be generated.
The cost of wind power is frequently highlighted as a reason not to implement the technology, with claims it adds to household bills.
Industry group, the Irish Wind Energy Association (IWEA), says it costs around €2m to install one megawatt of wind generation, which is sufficient to power about 850 homes. To encourage investment, the Government sets a guaranteed price for each megawatt produced at €69 per hour, called a REFIT (Renewable Energy Feed-In Tariff).
"People are not going to take the risk without reward," IWEA chief executive Kenneth Matthews says. "Developers are helping governments meet renewable targets. The cheapest way to meet those targets is through wind."
He says that a 5MW wind farm, "with everything going well", produces power about 30pc of the time. The price paid for electricity generated from that farm is guaranteed at around €900,000.
The public, therefore, subsidises wind energy though the REFIT scheme, but also by paying a charge on their bills called the Public Service Obligation (PSO). It amounts to €17.20 a year to subsidise wind power production, according to the regulator, the Commission for Energy Regulation (CER).
Customers also pay an additional €31.46 to subsidise the cost of having back-up power available, and to fund peat-burning plants, a payment which, for some reason, attracts little comment from opponents of wind.
There's sound economic reasons for having these supports in place. Because wind generation is "free" and does not involve burning oil or gas, it helps reduce the price for all electricity customers. We currently avoid spending some €200m a year importing fossil fuels because of the amount of wind on the system.
Electricity prices are based on the 'wholesale' price of power. Generators producing from oil, gas, hydroelectricity and other sources submit a bid price to the Single Electricity Market Operator (SEMO) to produce power in half-hour blocks the following day.
For example, the price could be €50 per megawatt hour (MWh) between 10am and 10.30am, rising to €75 per MWh between 6pm and 6.30pm. The cheapest power available at a given time is transmitted by EirGrid, the national grid operator, and all power suppliers including ESB and Bord Gais "draw" from this pool of electricity to supply their customers.
The 'average' price of power per half-hour block is paid to all the generators. When the wind is blowing, there is less need for conventional power, which reduces prices.
But key to the argument for wind is security of supply. Ireland is at the end of a very long pipeline, and having an indigenous source of energy gives us some comfort in the event of global shortages or political turmoil resulting in supplies being cut off.
That said, those opposed to wind farms have a range of legitimate concerns. There are issues involving shadow and flicker caused by the turbines, the thoroughbred industry has raised concerns about the impact farms will have on our world-renowned industry, while estate agents have also warned that property prices fall when wind turbines are erected nearby.
There is also concern about large-scale farms for the midlands designed to serve the UK market. Not until the British and Irish governments reach agreement can these projects go ahead, and only after planning and other permissions are obtained.
Some changes to planning rules are proposed. Earlier this year, the Department of the Environment published a consultation paper on proposed new guidelines for wind energy development.
No turbine should be closer than 500m to a home, they say. If issues of shadow or flicker arise, the turbine must be powered down until weather conditions improve and the problem is eliminated. Energy Minister Pat Rabbitte says deployment of wind energy is a hedge against future price hikes. "If you've a rich, indigenous resource capable of being exploited, why wouldn't you use it?" he says.
Even in a worst-case scenario, that fossil fuel prices plummet and wind ends up being more expensive, we will at least have reduced greenhouse gas emissions by avoiding burning fossil fuels. Given that turbines have a lifespan of about 25 years, when they come to the end of their lives we can always taken them down.