Wind facts - the myths and the truth
Wind is ‘the most mature and cost-effective source of renewable energy’ (RenewableUK web site)
Greenhouse gas emissions have increased by 40% since pre-industrial times and continue to steadily increase (a record 34 billion tonnes of carbon dioxide were emitted globally in 2011). Most of these emissions come from burning fossil fuels without carbon capture. Consequently the average global surface temperature has increased by 0.8°C since pre-industrial times. Very simply, this is why sea level is rising, Arctic ice is melting and extreme weather events are becoming more common. Climate scientists are predicting that by 2100 the temperature will exceed 2°C (the ‘safe’ limit) and may even reach 3.5°C with disastrous consequences. The solution is to drastically reduce greenhouse gas emissions NOW.
Arguments in favour of onshore wind farms.
1. The UK, lying on the NE margin of the North Atlantic Ocean, is well very placed with prevailing SW winds.
2. Onshore wind is by far the cheapest large-scale renewable energy source that can be deployed at significant scale.4 Wind provides a free source of energy. A wind farm is not exposed to fluctuations of energy prices in the market place. So, once constructed, the running costs of a wind farm are very low.
4. Wind farms don’t produce greenhouse gases in operation. Onshore wind energy has a very small carbon footprint with a range of 8 - 20g CO2eq/kWh4relative to electricity from fossil fuel power stations which generates 590g CO2eq/kWh.
5. It is UK government policy to expand the contribution of onshore wind farms to national needs. Wind farms contribute to meeting published emissions targets and to the country’s energy security.
6. Wind farms are already producing electricity in UK. In 2011, onshore wind:[iii]
- generated enough power for 2.4 million homes
- cost just £6 per household electricity bill in terms of subsidies
- supported more than 8,600 jobs
- saved more carbon emissions than the footprint of a city the size of Leeds (population 750,000).
7. A wind farm takes up less than 5% of the land area within which the farm is built. On that basis it is about ten times better than solar PV in terms of energy produced per hectare.
8. A wind farm is usually given planning permission for a lifetime of 25 years. When the wind farm is decommissioned the land can be returned to the land owner (although there may be a benefit in retaining some service roads).
9. Local inhabitants can benefit from a wind farm by negotiating reduced electricity tariffs (e.g. Good Energy, Delabole, Cornwall, November 2012) and/or annual grants which can be spent by the community.
Arguments against the criticisms commonly used by objectors
1. ‘Wind turbines are inefficient’. This interpretation turns on the meaning of the word ‘efficiency’. Wind turbines are 33% efficient in converting the kinetic energy of the wind into electricity.[iv] What objectors usually mean is that the wind is variable. Of course this is true at any one site but on a national scale it is very rare that the wind is not blowing somewhere. Variability at any one site is expressed as the load factor which is that proportion of the maximum possible output in a year which the turbine actually delivers. Onshore this is typically around 25%.
2. ‘Wind turbines need back-up’. This is equally true of a nuclear or fossil-fuelled power station when it is down for maintenance or an unexpected break-down occurs. Low wind can be forecast 48 hours in advance and plans made temporarily for alternative sources of electricity. At the contribution currently expected of wind farms by 2020 (up to 20% of all the UK’s electricity) this is not a problem. Existing plant can cope.
3. ‘Wind turbines are heavily subsidised’. An energy supplier can lose money through the Renewable Obligation Certificates (ROCs) if they install turbines on a poor site. Other subsidies may exist but wind energy is probably no more subsidised than fossil fuel or nuclear power stations were in the past. Many farmers in rural areas (even those objecting to wind farms) also benefit from EC subsidies for their agricultural activities.
4. ‘Wind farms are noisy’. Turbines can occasionally produce an annoying low frequency sound which troubles a few people but generally they are very quiet . Sheep happily graze beneath them. The distance of turbines from residential buildings is determined by planning authorities.
5. ‘Wind farms take up a lot of land’. Actually the footprint of a wind farm (turbine foundation pads, service roads, electricity sub-station) is less than 5% of the area in which the turbines are located.[v] The rest of the land can be used by grazing livestock or even for arable crops. The UK has to move away from high energy density fossil fuels, however attractive, in the direction of less energy dense renewable energy.
6. ‘Money would be better spent on researching other renewable technologies’. Wind is a mature, well tested technology which can be installed now. Yes, we should research other renewable technologies too, such as waves and tidal currents, but it may take decades to arrive at a commercial product. Mankind can’t afford to wait that long to begin to halt global warming.
7. ‘Wind farms cause urbanisation/industrialisation of the countryside’. The Hampshire countryside might already be considered to be industrialised by the large scale growth of arable crops and by intensive rearing of pigs and chickens for example. Wind turbines do not have to be a permanent feature of the countryside and at the end of their life, or planning permission, can be removed almost without trace.
8. ‘Wind farms are unsightly’. This is probably the ONLY valid objection to wind turbines. But it is a subjective view; some people like turbines, others don’t. When put into the context of the UK’s (and the world’s) urgent need for non-greenhouse gas emitting sources of energy this is a cost which unfortunately some people will have to bear for the greater good.
Bob Whitmarsh, WinACC Science and Technology Advisory Panel, 5 April 2013
[i] RenewableUK web site
[iv] Shorter, B. (2012). Electricity from wind energy in the UK. Winchester, STAP/WinACC: pp.7.