Wind energy

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, [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, [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.



In 1997, the UK Government signed up to the Kyoto Protocol, an international treaty designed by the United Nations Framework Convention on Climate Change (UNFCCC) to reduce the collective greenhouse gas emissions of the international community. The Protocol came into force in 2005 when Russia became the 55th country to sign up to the agreement and now provides the foundations for all national and international emissions reduction targets.

In November 2008, the UK Government passed legislation that introduced the world’s first long-term, legally binding framework to aid the fight against climate change, the ‘Climate Change Act 2008’. The Act bound into law the UK’s ambitious greenhouse gas emissions reduction target of 34% by 2020 and 80% by 2050, against 1990 emissions base levels.1 In addition, the ‘Committee on Climate Change’ was created as an expert advisory body to the Government on the UK’s progress towards its targets and budgets.

In July 2009, the UK Government implemented a strategic commitment through ‘The UK Renewable Energy Strategy’, which outlined the steps required to meet the UK’s obligation, under the ‘2009 Renewable Energy Directive’, of providing 15% of energy consumption from renewable sources by 2020.2

The Renewable Energy Roadmap3 published in 2011 and updated in 2012 sets out a strategy for meeting the ambitious 2020 consumption target. The Roadmap sets out a portfolio approach to the UK’s future energy policy, with the range of renewable technologies playing an important role. In its central scenario, onshore wind is expected to contribute 13GW of installed capacity.

Government currently estimates that due to plant closures and the need to replace and upgrade the UK’s electricity infrastructure, around £110bn of capital investment will be required. Its Electricity Market Reform (EMR) legislation is intended to attract the investment needed to replace our ageing energy infrastructure and meet future predicted increases in demand due to the expected electrification of the transport and heat sectors.4 EMR is the Government’s initiative to ensure that the UK remains a leading destination for low carbon electricity investment. The key measures EMR intends to implement are:

•    A capacity based market; and
•    Contracts for Difference (CfDs)

CfDs are intended to provide predictable revenue streams for low carbon electricity generators, including renewables, and the capacity based market is intended to ensure that there is always spare electricity generating capacity, avoiding shortfalls at times of high demand.

The 5th report by the Intergovernmental Panel on Climate Change, published in September 2013, states that human influence is extremely likely to have caused recorded increases in temperature, sea level rises and changes in some climate extremes.

1 Department of Energy and Climate Change [DECC] (2011) Climate Change Act 2008,, [accessed 23.08.13].

2 Department of Energy and Climate Change [DECC] (2013), Increasing the use of low-carbon technologies, [accessed 23.08.13].

3 Department of Energy and Climate Change [DECC] (2013), 5 Department of Energy and Climate Change [DECC] (2012) Renewable Energy Roadmap update 2012,, [accessed 23.08.13].

4 Department of Energy and Climate Change [DECC] (2013) Maintaining UK Energy Security: Electricity Market Reform. [accessed 23.08.13].

The UK’s electricity system is ageing, requiring significant investment in new power generation capacity and grid infrastructure. The indigenous fossil fuels currently used to generate electricity are a finite resource and the UK is becoming increasingly reliant on fuel imports. Global competition for fossil fuels, alongside political instability in the Middle East, is resulting in volatile prices here in the UK. Wind energy, however, is an unlimited, domestic, clean power source with vast generation potential: there are no fuel costs, no political risks and no import dependencies.

Furthermore, the Large Combustion Plant Directive (LCPD) places strict limits on the emissions of conventional thermal power stations, and is likely to result in the closure of many of the UK’s large coal fired power stations, placing further strain on the domestic electricity supply chain. Add this to the fact that a large percentage of the UK’s ageing fleet of nuclear power stations is due to be decommissioned in the near future, and it is clear that the UK faces a serious and compelling challenge to keep the lights on.

Ofgem is now required to produce annual reports for Government on electricity supply security and in 2013, for the second year running, the report found that the risks to security of supply are increasing, with an expectation that there will be a shortfall against demand this decade.1

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 in the long run. Money invested in wind power today therefore has the potential to have a significant effect in reducing future electricity prices.

Currently, the UK energy sector requires major sustained investment in order to secure energy supply for the future and enable the UK to meet ambitious national and international renewable energy targets. Wind power can be deployed faster than most other energy supply technologies and, as such, offers a cost effective and timely solution for indigenous energy generation.

Although wind power could never provide the whole solution, we believe it has a very important role to play in the future energy generation mix for the UK.

1 Ofgem (2013) Electricity Capacity Assessment Report 2013, [accessed 23.08.13].

As published by Renewable UK :; calculated using the Digest of UK Energy Statistics [DUKES] figures: [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,]

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

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


• 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,

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,].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,