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 Department of Energy &Climate Change in its June 2011 publication "The UK Renewable Energy Roadmap". The Roadmap estimates that onshore wind could contribute up to around 13GW of installed capacity by 2020.
The majority of this would be from large scale projects over 5MW. Achieving this 9GW increase would require an annual growth rate of 13% over the next decade, slightly less than the growth rate experienced between 2009 - 2010.¹
The wind energy market has made substantial advances in recent years. In 2011, wind accounted for 30% of all new renewable capacity installations within the EU, the second largest share after solar PV (66%). This brings the total installed capacity of wind within the EU to nearly 94GW.² Within the UK alone, there is now over 6.6GW of installed wind generating capacity across over 3,744 turbines.³ The growth in wind energy generation has been driven by several factors: the increased awareness of climate change, policy and protocol, the wider context of energy supply and demand, and security of supply.
¹ Department of Energy & Climate Change [DECC] (2011) UK Renewable Energy Roadmap, http://www.decc.gov.uk/en/content/cms/meeting_energy/renewable_ener/re_roadmap/re_roadmap.aspx [accessed 07.06.12].
² European Wind Energy Association (2012) Wind in power: 2011 European statistics, [accessed 06.06.12].
3 RenewableUK [formerly named BWEA] (2012) UK Wind Energy Database - UKWED, http://www.bwea.com/ukwed/index.asp [accessed 06.06.12].
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 & Climate Change [DECC] (2009), The UK Low Carbon Transition Plan [accessed 07.06.12].
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 adoption of both policy and protocol at both national and international levels.
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.
The fate of the Kyoto Treaty, which is due to expire at the end of 2012, has been a key subject of debate since 2008. In December 2009, the UNFCCC held its 15th session of the Conference of the Parties (COP 15) in Copenhagen, Denmark, in aid of negotiating a successor agreement to the Kyoto Protocol. Whilst it failed to turn government pledges into legal commitments, the accord it produced broke new ground on international and co-operative action, and was endorsed by over 110 countries. In December 2010, COP 16 took place in Cancun, Mexico. Whilst decisions on the future of the Kyoto Protocol were effectively deferred to the following year's COP 17 in South Africa, the outcome of the summit was an agreement adopted by members that further emphasised the need for the 2020 emission reductions targets, as pledged in the Copenhagen Accord, and in addition, called for 'developing' countries to draw up plans to reduce their emissions levels. In aid of doing so, a 'Green Climate Fund' was founded within the framework of the UNFCCC, with an objective to raise $100 billion a year by 2020 in order to assist 'developing' countries in adaptation and mitigation practices to counter climate change.
More recently, in December 2011, the 17th United Nations Climate Change Conference [UNCCC] was held in Durban, South Africa, with the overarching aim of establishing a new treaty to limit global carbon emissions. Despite the fact that a new treaty to replace the Kyoto Protocol was not agreed upon, the primary outcome of COP 17 was the establishment of the Ad Hoc Working Group on the Durban Platform for Enhanced Action. The 'Durban Platform' agreement sets out a path to negotiate a new 'universal' emission reductions arrangement by 2015, which is to be officially adopted by 2020 and whose targets would be applicable, for the first time, to both 'developed' and 'developing' countries. It was agreed that in the interim, UNFCCC members should enter into a secondary commitment period to the Kyoto Protocol, which will commence in early 2013 and is expected to last until 2020, albeit the expiration date has not yet been decided upon. The 18th UNCCC (COP 18), to be held in Qatar at the end of 2012, is expected to present further clarification upon the matter.
In July 2011, the UK Government's Department of Energy & Climate Change published the 'UK Renewable Energy Roadmap', which sets out a comprehensive action plan to accelerate deployment and hence the use of renewable energy technologies 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 a legally binding target imposed upon UNFCCC EU member countries by the Copenhagen Accord, established at COP 16. The Roadmap focusses upon eight technologies that have the greatest potential to help meet the 2020 target. Onshore wind is identified as the largest single contributor to the current renewable energy pipeline, with over 11GW of capacity in planning, consented or under construction. This indicates that onshore wind could contribute up to around 13GW by 2020, which equates to an annual growth rate of 13% over and above the 4GW presently installed.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 EU Renewable Energy Directive, are ever more likely.³
In December 2011, the UK Government published the 'Carbon Plan', which sets out plans for achieving the emissions reductions committed to in the first four carbon budgets, a pathway consistent with lowering the six Kyoto greenhouse gases below 1990 base levels by a minimum of 80%; a legally binding target established by the 'Climate Change Act 2008'. 4
² Department of Energy & Climate Change [DECC] (2011) UK Renewable Energy Roadmap, http://www.decc.gov.uk/en/content/cms/meeting_energy/renewable_ener/re_roadmap/re_roadmap.aspx [accessed 07.06.12].
³ Department of Energy & 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 07.06.12]
4 Department of Energy & Climate Change [DECC] (2008), Climate Change Act 2008, http://www.decc.gov.uk/en/content/cms/legislation/cc_act_08/cc_act_08.aspx [accessed 07.06.12].
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 jointly published in a report by the Department of Energy & Climate Change and 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 has the potential to significantly reduce 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. In June 2011, the Committee on Climate Change published its 3rd Annual Report 'Meeting Carbon Budgets', which emphasises the necessity to accelerate the pace of investment in wind over the next two decades3, further accentuating the need for increased domestic supply.
¹ Department of Energy & Climate Change [DECC] (2009) Energy Markets Outlook [accessed 07.06.12].
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 07.06.12].
3 Committee on Climate Change (2011) 3rd Annual Report: Meeting Carbon Budgets, http://www.theccc.org.uk/reports/2nd-progress-report [accessed 07.06.12].
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].
• 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
• 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
• 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]
• 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 2011, the total installed capacity of wind turbines globally was 237,669MW, whilst in 2000 it was 17,400MW [Global Wind Energy Council 2012, www.gwec.net].This represents a 1,266% rise in global capacity since 2000.
‘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]