The UK is currently facing two significant challenges with its energy supply. Firstly, ageing conventional power stations are coming to the end of their operational lives, which will leave a huge shortfall in its electricity supply. At the same time imported natural gas, primarily from less stable parts of the world such as Russia and the Middle East, is being relied upon for an ever increasing portion of the UK’s energy supply. Secondly, it is widely recognised that climate change is the single largest environmental threat facing the planet, and that it is primarily due to the burning of fossil fuels. As our electricity supply is one of the major consumers of fossil fuels there is an urgent need to find alternative sources of energy.

The UK is home to one of the most abundant wind resources in Europe. Wind is not only a free, natural resource, but it is also one of the most viable, advanced and developed technologies currently available for renewable electricity generation. Furthermore, the development process, from project inception to operation, is far quicker than that of other forms of conventional and alternative power generation.

The important role that wind energy can play in reducing our emissions was recognised by the Committee on Climate Change in their 2nd Annual Report where it is stated that:

"wind generation offers the best opportunity for early decarbonisation of the power sector because it is the only low-carbon technology that is ready for large scale deployment now." ¹

The wind energy market has made substantial advances in recent years. In 2009, more wind power capacity was installed within the EU than any other generating technology, now with a total installed capacity of nearly 75,000MW.² Within the UK alone, there is now over 4,500MW of electricity generated across over 2,900 turbines.³ The growth in wind energy generation has been driven by several factors: the increased awareness of climate change, policy & protocol, the wider context of energy supply & demand, and security of supply.

¹ Committee on Climate Change (2010) 2nd Annual Report: Meeting Carbon Budgets - ensuring a low-carbon recovery, http://www.theccc.org.uk/reports/2nd-progress-report [accessed 16.09.10].

² European Wind Energy Association (2010) Wind in power: 2009 European statistics, http://www.ewea.org/index.php?id=1665 [accessed 16.09.10].

³ RenewableUK [formerly named BWEA] (2010) UK Wind Energy Database – UKWED, http://www.bwea.com/ukwed/index.asp [accessed 16.09.10].

Over the past 100 years the Earth’s average atmospheric temperature has dramatically increased above natural fluctuations. It has been established that this significant level of warming correlates with the combustion of vast quantities of fossil fuels, which has led to the emission of equally vast quantities of harmful greenhouse gases.

Carbon dioxide is presently the largest contributing factor to global warming and therefore anthropogenic climate change, with average global levels rising 20% over the last 45 years. The following graph illustrates the correlation between carbon dioxide levels in the atmosphere and global average temperature trends.

Source: Department of Energy and Climate Change [DECC] (2009), The UK Low Carbon Transition Plan, http://www.decc.gov.uk/en/content/cms/what_we_do/lc_uk/lc_trans_plan/lc_trans_plan.aspx [accessed 16.09.10].

Climate change is recognised by the global scientific community as the single largest environmental threat facing the planet and its inhabitants. The effects of global warming are evident across the globe, as demonstrated by the retreat of glaciers, rising sea levels and increasing frequency of severe weather events.

Evidence of these effects are endorsed by both national and international organisations, such as the Department of Energy & Climate Change [DECC] and the Intergovernmental Panel on Climate Change [IPCC]. This has led to the compiling of various synthesis reports, which have in turn initiated the drafting of both policy and protocol at both national and international level.

The Kyoto Treaty was initially adopted on 11th December 1997 as a protocol to the United Nations Framework Convention on Climate Change [UNFCCC]. The Treaty prioritises the stabilisation of greenhouse gas atmospheric concentrations, aimed at mitigating anthropogenically induced climate change.

In December 2009, the business grouping behind The Prince of Wales's Corporate Leaders' Group on Climate Change met in Copenhagen to negotiate a successor agreement to the Kyoto Protocol. Whilst a final agreement was not reached, over 950 member companies, from over 60 countries attending the meeting, issued a communiqué stating:

"... The business community will, I’m sure, welcome the fact that the world’s major economies have, for the first time, made commitments to curb emissions and this provides a clear signal that the sensible money is in low-carbon.

[...] a legally binding deal is needed as a matter of urgency to provide business with the confidence it needs to invest in specific low-carbon technologies and infrastructure.

[...] The Corporate Leaders' Group is ready to work with governments, NGOs and other business groupings to secure an ambitious, robust and equitable legally binding UN deal as soon as possible in 2010." ¹

In July 2009, the UK Government implemented strategic commitment through ‘The UK Renewable Energy Strategy’, which outlined the steps required to meet the UK's obligation, under the 'EU Renewable Energy Directive', of providing 15% of energy generation from renewable sources by 2020. This is almost a seven-fold increase in the share of renewables in scarcely more than a decade, potentially reducing the UK's emissions of carbon dioxide by over 750 million tonnes between now and 2030.²

The main mechanism for supporting large scale generation of renewable electricity is currently the Renewables Obligation [RO]. Through placing an obligation on licensed electricity suppliers to source a specified and annually increasing proportion of their electricity sales from renewable sources or pay a penalty, prospects of reaching such stringent targets, such as that of the UK Renewable Energy Strategy, are ever more likely. ³ 

In July 2009, the Government published ‘The UK Low Carbon Transition Plan’ which sets out plans to achieve the 2020 target of reducing greenhouse gas emissions by 34% from 1990 levels. ⁴

¹ The Prince of Wales's Corporate Leaders Group on Climate Change (2009), Copenhagen conference: The verdict from business - "Not done yet" http://www.copenhagencommunique.com/images/stories/verdict-from-business-not-done-yet.pdf [accessed 28.10.10].

² Department of Energy and Climate Change [DECC] (2009), The Renewable Energy Strategy (RES), http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energy_mix/renewable/res/res.aspx [accessed 16.09.10].

³ Department of Energy and Climate Change [DECC] (2009), Renewables Obligation, http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energy_mix/renewable/policy/renew_obs/renew_obs.aspx [accessed 28.10.10]

⁴ Department of Energy and Climate Change [DECC] (2009), The UK Low Carbon Transition Plan, http://www.decc.gov.uk/en/content/cms/what_we_do/lc_uk/lc_trans_plan/lc_trans_plan.aspx [accessed 16.09.10].

The demand for energy is ever increasing, requiring significant investment in new power generation capacity and grid infrastructure. The indigenous fossil fuels currently used to generate electricity supply are becoming significantly depleted, resulting in an increasing reliance upon imported sources. Global competition for these imported resources can reduce supply confidence and inevitably result in volatile prices. In addition to these factors, the requirement to reduce carbon emissions levels creates a serious problem for the security of the UK's energy supply. As published by Ofgem, UK regulator of electricity and gas markets, secure supply is expected to last until around 2015¹. Wind energy, however, is an unlimited domestic clean and free power source with vast generation potential: there are no fuel costs, no geo-political risks and no import dependency.

As global demand for fossil fuels increases, so too does the price, resulting in a higher cost for the electricity consumer. Wind farms do not have to purchase fuel and therefore help to keep electricity costs down in high fuel price environments. Money invested in wind power generation today will therefore have a significant effect in reducing future electricity prices.

Currently, the UK energy sector requires major sustained investment in order to secure energy supply and enable the UK to meet ambitious national and international renewable energy targets. Wind power can be deployed faster than any other energy supply technology² and, as such, offers a cost effective and timely solution for such indigenous energy generation, not only in consideration of supply security, but in ensuring the targeted reductions in emission levels are met.

¹ Ofgem (2010) Project discovery - Options for delivering secure and sustainable energy supplies, http://www.ofgem.gov.uk/Pages/MoreInformation.aspx?file=Project_Discovery_FebConDoc_FINAL.pdf&refer=Markets/WhlMkts/Discovery [accessed 16.09.10].

² Committee on Climate Change (2010) 2nd Annual Report: Meeting Carbon Budgets - ensuring a low-carbon recovery, http://www.theccc.org.uk/reports/2nd-progress-report [accessed 16.09.10].

As published by Renewable UK : www.bwea.com; calculated using the Digest of UK Energy Statistics [DUKES] figures: http://decc.gov.uk/en/content/cms/statistics/source/renewables/renewables.aspx [calculation assumes a 2.5MW turbine, producing 6.5million units of electricity per annum].

Assumptions:

• REpower MM92 (2MW) turbine with site average wind speed of 7.2m/s at hub height would produce on average: 6,000MWh per annum

• Standard kettle rating: 2.2kW

• Specific heat capacity of water: 4.187kJ/kgK

• Average tap water temp across the year: 10 ⁰C

• Average volumetric capacity of a tea cup: 250ml

• Density of tap water: 1000 kg/m3

Calculations:

• Weight of a cup of tea: Volume x density = weight

• Temperature raise required: Required temp (boiling) – existing temp = required raise

• Energy required to heat a cup of tea to boiling: Specific heat capacity of water x weight of water x required temperature raise

• Time taken to boil 1 cup: Required energy / energy delivered

• Therefore; in 1 hour (3600 seconds), a kettle would consume 2.2kWh and produce 38 cups of boiling water.

• Hence; for each single kWh produced, 38 cups of water could be boiled

• The wind turbine would generate 6,000,000 kWh, which equates to ...

= 228 million cups of tea

Assumptions

• REpower MM92 (2MW) turbine with site average wind speed of 7.2m/s at hub height would produce on average: 6,000MWh per annum

• Car emissions based on petrol vehicle weighing less than 2.5 tonnes, with engine size greater than 2,000 cc and assuming urban driving: 269 g/km CO₂ [Department for Transport Emissions Factors 2009, www.dft.gov.uk]

• Average annual distance travelled per car: 8,690 miles per car (13,985 km) [Transport Statistics Great Britain 2009, www.dft.gov.uk]

• Current UK grid emissions factor 0.46 kg/kWh [Department for Energy and Climate Change 2009, www.decc.gov.uk]

Calculations

• Annual emissions per car: Distance travelled (8,690) x emissions per km (269g)

• Annual emissions saving per turbine: Energy produced (6,000 MWh) x average grid emissions factor (0.46 kg/KWh) = 2,760t CO₂ per turbine

• Car CO₂ offset from 1x turbine: Emissions saving kg / emissions per car kg

= 734 cars per annum

The UK is the windiest country in Europe, so much so that we could power our country several times over using this free fuel. [Renewable UK 2010, http://www.bwea.com/onshore/index.html] 

At the end of 2010, the total installed capacity of wind turbines globally was 194,390 MW whilst in 2000 it was 17,400 MW [Global Wind Energy Council 2010, www.gwec.net]. 

‘Like waterwheels, windmills were among the original prime movers that replaced human beings as a source of power. The use of windmills was increasingly widespread in Europe from the 12th century until the early 19th century.’ [Encyclopaedia Britannica 2010, http://www.britannica.com/EBchecked/topic/645158/windmill]