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Wind Energy FAQ

What is a wind farm?

A wind farm is comprised of a group of wind turbines located relatively in the same area which are then interconnected with a medium voltage power collection system together with a communications network. A substation is also located on site. At the substation, this medium-voltage electrical current is increased in voltage with a transformer for connection to the higher voltage transmission system.

How efficient is wind energy?

Wind turbines produce electricity approximately 85% of the time. The other 15% of the time they are not turning for reasons, such as: very low wind speeds, very high wind speeds, and maintenance/repair work. After six to seven months, a wind turbine will have produced as much energy as it has consumed constructing it. 

(Source; ESB -

The output of a wind turbine depends on the turbine's size and the wind's speed through the rotor. A wind turbine with a net capacity factor of 35% and a capacity of 4.2 MW can produce more than 12,800 MWh in a year – enough to supply more than 3,000 average Irish households. (Source; Eirgrid -

What happens when the wind stops blowing?

The power grid operator constantly matches the electricity generation available to electricity demand. No power plant is 100% reliable, and the electricity grid is designed to cope with power plants shutting down unexpectedly, and times when the wind is not blowing. Wind is variable, but predictable. Wind farm sites are chosen after careful analysis of wind patterns. This enables a forecast of output to be made - information which can be made available to the network operators who will distribute the electricity.

In the future, once a truly European electricity grid has been constructed, wind-powered electricity will be able to be traded between EU countries to balance out supply and demand even more easily. Other renewables such as solar will also form part of this electricity exchange.

(Source: EWEA -

What is the current situation of wind energy in Ireland?

Wind energy is currently the largest contributing resource of renewable energy in Ireland. It is both Ireland’s largest and cheapest renewable electricity resource. In 2018 Wind provided 85% of Ireland’s renewable electricity and 30% of our total electricity demand. It is the second greatest source of electricity generation in Ireland after natural gas. Wind provided 37 per cent of the State’s electricity in the first three months of 2019, surpassing even natural gas in this period. There are over 250 wind farms in the Republic of Ireland, amounting to a total installed capacity of 3,700 MW.

(Source; SEAI -

(Source; IWEA -

What is the future for wind energy in Ireland?

The Climate Action Plan to Tackle Climate Breakdown, issued by the Department of Communications, Climate Action and Environment (DCCAE) in June 2019, commits Ireland to supplying 70% of our electricity needs from renewable sources by 2030. According to this paper, this is likely to involve the addition of over 12 GW of renewable capacity, of which the government recommends that 8.2 GW, or 68%, should be onshore wind. This recommendation is based on their Marginal Abatement Cost Curve (MACC) analysis, showing wind energy to be Ireland's most economic solution to our energy targets and a vital component in the future of Irish energy.

(Source; DCCAE -

What is RESS?

In July 2018, the Department of Communications, Climate Action and Environment (DCCAE) released the Renewable Electricity Support Scheme (RESS) High Level Design (HLD) paper, which outlines a series of auctions, designed to help Ireland achieve its 2020 and 2030 energy targets.

The first RESS auction will commence in Q4 2019, and it is believed that 1,000 GWh of annual generation will be auctioned in this first round. According to the RESS HLD paper, this would require around 356 MW of onshore wind energy.

Providing pathways for increased community participation will be a cornerstone of the new scheme, delivering on Energy White Paper commitments. It is proposed that a contribution of €2/MWh for all RES-E generation produced and seeking support via RESS auctions is provided to the local community involved.


Additionally, investment opportunities for communities and citizens in all RESS projects will be provided. To qualify for RESS auctions, projects will have to meet community investment criteria. It is proposed that projects will have to facilitate the registration of interest in investing by individuals prior to participating in RESS auctions. If successful in the auctions, these individuals will then have the opportunity to realise this investment option. This phased approach will significantly de-risk the investment procss for individuals.

(Source: DCCAE -

Why do governments promote onshore wind power rather than other renewable technologies?

Governments tend not to promote one technology above another. The reason that wind power has been popular is because of its cost effectiveness. In the short to medium term, alternatives are less attractive to developers and state subsidy providers.  Hydroelectric power using large dams was popular until recent times. However, the social and environmental problems caused by the flooding of valleys and large areas of land means that future hydro schemes are likely to be smaller and river-based. Solar power is generally more costly than wind in countries like Ireland and Britain today, though it is reducing rapidly in cost and can be effective when integrated into new buildings.  Tidal and wave power technologies are not as well developed as wind, although the long term future offers potential.

(Source; UK Sustainable Development Commission -

The first RESS auction (RESS-1) is intended to follow a purely "technology neutral" approach. This means that all qualifying renewable energy technologies will compete against each other for the lowest cost of electricity, guaranteeing the consumer the cheapest renewable energy, regardless of source. In subsequent RESS auctions, a technology cap is intended to be introduced, whereby a limit is placed on the portion of each round a given technology can win. This is will prevent one technology winning the entire auction and ensure more diversity in our energy mix, though at an increased cost.

As onshore wind is presently the cheapest renewable technology, this measure is an example of the government actively promoting other technologies at the expense of onshore wind energy.

What has wind energy cost the Irish consumer?

In January 2019, management and research consultancy, Baringa, conducted a financial impact analysis for end consumers of wind generation in Ireland over the period 2000-2020. The analysis indicated that the deployment of 4.1 GW of wind generation capacity in Ireland
between 2000 and 2020 will result in a total net cost to consumers, over 20 years, of €0.1bn (€63
million to be exact), which equates to a cost of less than €1 per person per year.

(Source: Baringa -

In the near future, as wind energy reaches cost competitiveness with new and existing gas fired plants, there will be a net financial benefit to electricity consumers for each turbine installed, in addition to all of the environmental and health benefits.

Aren't wind farms widely unpopular?

This is a common misconception resulting from the disproportionate coverage generated by small minority opposition groups. An opinion poll conducted by Interactions Research and commissioned by IWEA in November 2018 discovered the following:

  • 83% in favour of the use of wind power (54% strongly in favour)

  • 81% of rural residents favour the use of wind power (55% strongly in favour, up 12 points since 2017)

  • 87% say Ireland should promote an indigenous source of energy and not rely on imported fossil fuels (56% strongly in favour, up 11 points since 2017)

  • 80% would choose renewables over fossil fuels to power their homes (up 10 points since 2017)

  • 82% see reduced CO2 emissions as a benefit of wind power (up 8 points since 2017)

  • 77% see cheaper electricity as a benefit of wind power (up 9 points since 2017)

  • 55% are in favour of a wind farm set up in their local area – up 9 points since last year (46%)

(Source: IWEA -

Aren’t wind farms a real blot on the landscape?

Some people find wind farms unacceptably intrusive in our much loved countryside. Others see them as graceful structures, generating local civic pride – unlike electricity pylons, for example, which we have lived with for decades. It’s a highly subjective judgement. Climate change – unless tackled effectively now – is far more likely to have a severe and widespread impact on the landscape in the longer term than wind plants. Our willingness to save energy and reduce our dependence on traditional means of power generation will help to safeguard the landscape for the use and enjoyment of future generations.

(Source; UK Sustainable Development Commission -

Do wind farms require overhead transmission lines or electrical pylons?

No. EMPower wind farms involve the installation of no electrical pylons or overhead transmission lines. Instead, all transmission lines will be buried out of sight in the form of underground cables. EMPower will endeavour to create the minimum visual and ecological impact by locating these transmission lines along existing public roads and access tracks where possible.

Are wind farms harmful to people's health?

Scientific evidence and human experience to date concludes that wind turbines are not harmful to human health – in fact, wind energy reduces harmful air emissions compared to traditional electricity sources. Concerns over impacts on health from wind farms are usually raised in relation to noise, shadow flicker, infrasound, electro-magnetic fields or vibration. The Irish Health Service Executive (HSE), in their Position Paper on Wind Turbines and Public Health (2017), state that “there is no published scientific evidence to support adverse effects of wind turbines on health.” This conclusion is explicitely repeated by HSE in regards to the issues of noise, infrasound, electro-magnetic fields and shadow flicker. (Source: HSE -;jsessionid=787BB9B28B82F820B0AC68EA582FB088?sequence=3)

This finding is echoed by peer reviewed literature from institutions such as the Technical Research Centre of Finland (2013), Massachusetts Institute of Technology (MIT) (2014), and the Sydney University Medical School (2015).


In response to a Parliamentary Question in May 2014, the European Commission stated ‘The Commission keeps a continuous watch on the possible impacts of wind turbines on health and well-being, taking into account the results from on-going projects and other sources. So far there has been no scientific evidence of lasting impacts, but there is recognition, also in industry, of public perception of impacts and nuisance.’

(Source: Friends of the Earth Ireland -

Do wind farms make noise?

It is the duty of EMPower to demonstrate during the planning process noise levels of our turbines will not adversely affect local residents. The studies completed during this period will be used to design each new wind farm so noise levels at nearby residential homes do not exceed national planning guidelines. Currently in Ireland and the United Kingdom, guidelines in relation to wind turbine noise levels are set at: “35 and 45 decibels dependent on the time of day and the level of background noise”, in line with international best practices.

Do wind turbines emit harmful infrasound?

Infrasound, sometimes referred to as low-frequency sound, is generally regarded as sound that is lower in frequency than 20 Hz or cycles per second. Infrasound is an frequently present element of the natural and man-made environment. It is produced by sources such as sea waves, rainfall, animals, vehicle traffic, buildings, appliances and indeed, wind turbines, to name a few.


The overwhelming consensus in peer reviewed scientific literature, much of which is readily available on the internet, is that there is no sound evidence to indicate infrasound caused by wind turbines creates harmful health impacts. In 2016, the Ministry for the Environment, Climate and Energy of the Federal State of Baden-Wuerttemberg in Germany published an investigation into infrasound produced from wind turbines.


“Infrasound is caused by a large number of different natural and technical sources. It is an everyday part of our environment that can be found everywhere. Wind turbines make no considerable contribution to it. The infrasound levels generated by them lie clearly below the limits of human perception. There is no scientifically proven evidence of adverse effects in this level range. The measurement results of wind turbines also show no acoustic abnormalities for the frequency range of audible sound. Wind turbines can thus be assessed like other installations according to the specifications of the TA Lärm (noise prevention regulations). It can be concluded that, given the respective compliance with legal and professional technical requirements for planning and approval, harmful effects of noise from wind turbines cannot be deduced.”

(Source: Ministry for the Environment, Climate and Energy of the Federal State of Baden-Wuerttemberg -


Similar conclusions have also been reached by British Wind Energy Association/Renewables UK (2005), Sydney University

Medical School (2013), Massachusetts Institute of Technology (MIT) (2014) and The Quebec National Institute of Public Health (2015), to name a few.

Do wind turbines create harmful electro-magnetic fields (EMF)?

Wind turbines are not considered a significant source of EMF exposure since emissions levels around wind farms are low. The overwhelming scientific evidence is that there is nothing unique to wind farms with respect to EMF exposure; in fact, magnetic field levels in the immediate vicinity of wind turbines are regularly lower than those produced by many common household electrical devices and are well below any existing regulatory guidelines with respect to human health.

(Source: Chief Medical Officer of Health of Ontario -

(Source: Intrinsik Environmental Sciences -

Will local residents be affected by shadow flicker?

Shadow flicker refers to the effect of the sun (low on the horizon) shining through the rotating blades of a wind turbine, casting a moving shadow. Present planning guidelines require that any possible effects of shadow flicker are mitigated entirely by installing solar sensors on the turbine which slow or shut down the turbine during times of possible shadow flicker. Therefore, no residents will be affected.

(Source: Department of the Environment, Heritage and Local Government -


Do wind farms effect house prices?

Research from around the world has shown that wind farms do not impact on house prices. In Britain, the Centre for Economics and Business Research (CEBR), found that wind turbines did not effect property sale prices. In the United States, researchers supported by the US Department of Energy (2014) also reached this conclusion.

(Source: CEBR -

(Source: Hoen et al -

(Source: ESB -

What are a turbine’s lifetime emissions?

Wind energy emits no toxic substances such as mercury and air pollutants like smog-creating nitrogen oxides, acid rain-forming sulphur dioxide and particulate deposits. These pollutants can trigger cancer, heart disease, asthma and other respiratory diseases, can acidify terrestrial and aquatic ecosystems, and corrode buildings.

Wind energy creates no waste or water pollution. Unlike fossil fuel and nuclear power plants, wind technology uses very little water to produce electricity. Given the fact that water scarcity is pressing and will be exacerbated by climate change and population growth, wind energy is key to preserving water resources.

(Source: EWEA -


In 2014, the Intergovernmental Panel on Climate Change (IPCC) compared the lifetime CO2 equivalent [CO2(e)] emissions of all major energy technologies in operation worldwide. Onshore wind energy was found to have the lowest mean lifecycle emissions of all sources at 11 grams CO2(e) per kWh. In comparison nuclear energy had 12 grams CO2(e) per kWh, utility solar PV had 48 grams CO2 (e) per kWh and combined cycle natural gas had 490 grams CO2(e) per kWh.

(Source: IPCC -

Do wind turbines harm animals, birds and marine life?

Leading environmental and nature conservation groups like Birdlife, WWF, Greenpeace, Friends of the Earth, and Birdlife support wind energy. Birdlife recently stated that climate change was the single largest threat to birds and wind and renewables were a clear solution to climate change.

Wind farms are always subject to an Environmental Impact Assessment to ensure that their potential effect on the immediate surroundings, including fauna and flora, are carefully considered before construction is allowed to start. Deaths from birds flying into wind turbines represent only a tiny fraction of those caused by other human-related sources such as vehicles and buildings.

A 2012 study carried out in the UK (Pearce- Higgins et al.) concluded that a large majority of species can co-exist or thrive with wind farms once they are operating (Journal of Applied Ecology).

According to the Greening Blue Energy study, “Including both on and offshore facilities, estimated rates of mortality for different bird species range from 0.01 to 23 mortalities per turbine per year” (Drewitt & Langston, 2005). It has been estimated that wind turbines in the US cause the direct deaths of only 0.01-0.02% of all of the birds killed annually by collisions with man-made structures and activities.

(Source: EWEA -

Why not site wind turbines offshore?

The urgent need to respond to climate change means that we’ll need to use as many renewable resources as quickly as possible, including both onshore and offshore wind. At present onshore wind is one of the most economically competitive of the renewable technologies. Due to the technical hurdles of offshore construction and connection to the national grid, there is unlikely to be any offshore wind projects competing in the initial rounds of the RESS auctions. When projects and supporting grid infrastructure are ready, offshore wind will compete on price with other renewable technologies and the most economic solution will succeed. 


The offshore wind resource potential is considerable in Ireland, but due to technical and economic restrictions, onshore wind is currently the key technology if we are to reach our energy objectives.

(Source: EWEA -

What are the EIA subjects of study?

The following studies will be conducted;

Social Impact Assessment

  • This involves examining the social effects of infrastructure projects on the surrounding community. The impact of the wind farm on human beings will be assessed by completing a desk study and conducting site visits to the surrounding areas. This study will examine land use, employment, health and safety, tourism and local amenities. EMPower employs best practice guidelines to ensure any potential impacts are mitigated as early as possible.


  • An ecological impact assessment will be carried out for the wind farm to assess the impact on the sites natural environment (flora and fauna). The study involves identifying, quantifying and evaluating potential impacts of the wind farm on the local ecosystem. The findings of this study will inform the final design and position of the turbines.

Soils, Hydrology and Hydrogeology

  • The hydrology of the site refers to how water currently flows under and through the land. The final design will consider the soil and rock composition found onsite and will minimise any disturbance to drainage and ensure no interruption to residents’ drinking water supplies.

Noise Assessment

  • A noise assessment will be carried out to assess the impact of noise on the surrounding community. Sound level meters will be installed at sound sensitive locations (houses) to measure the existing background noise. The audible impact of the wind farm will be estimated using wind turbine noise curves. Turbines can then be positioned in order to mitigate adverse noise pollution to the local community.

Shadow Flicker

  • Shadow flicker refers to alternating changes in light intensity caused by the moving turbine rotors,   possibly impacting dwellings. This generally occurs only at sunrise or sunset when the shadows are very long. EMPower will carry out a shadow flicker analysis using computer software to ensure that the placement of each turbine does not result in any shadow flicker.

Civil Engineering

  • The civil engineering assessment details the design of the site access tracks, turbine foundations, crane hardstandings, sediment and erosion control measures for the protection of watercourses, traffic impact assessment and turbine site investigations. 

Landscape and Visual

  • A landscape and visual impact assessment will be carried out to ascertain the visual impact of the wind farm on the surrounding community and key transport routes. A zone of theoretical visibility (ZTV) will be produced outlining which turbines will be visible from various locations. Photo montages will also be produced showing the operational turbines in situ. 

Cultural and Archaeological Heritage

  • This study will include the identification of significant archaeological, and cultural heritage constraints on the site and surrounding area. The final design will ensure that any sensitive areas are protected throughout development

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