The UK requires commissioning of more than 20GW of new capacity by 2020. This represents around 22% of total installed capacity. However, it is not simply closures of existing plant that are important, but that the electricity network will contain more intermittent generation such as wind, and possibly wave generation, as well as more inflexible generation such as nuclear (DECC 2011a). This increases the challenge faced by National Grid in meeting demand at all times. Ofgem (2012a) clearly show that 2015 and 2016 are critical years, during which there will be a low capacity margin, the level by which available electricity generation capacity exceeds the maximum expected level of demand.
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Figure 3.5 shows a scenario generated from the following key information from the UK Government and Sector bodies with regards to capacity changes over the next decade. Peak Demand is taken from National Grid’s base case of 58GW that will not significantly change over the next decade notwithstanding significant new technology deployment. The other sources of information for individual technologies are shown below.
Coal, oil and mixed
The oldest operating UK coal power stations are 47 years old, of which there are three, one of which closed this year due to a fire (DECC 2013). The youngest is 32 years old. Six new power plants are planned and all will likely require CCS if they are to open in the UK (DECC 2012a). Significant closures totalling 12GW of coal-fired plant is scheduled by 2016 due to the Large Combustion Plant Directive (LCPD).
Nuclear
Only two nuclear plant type will be in operation by the end of this scenario since 16 reactors are to be retired by 2023 and one new plant (Hinkley C) will come online in 2023 and after a number of plants will have their operational lives extended (World Nuclear Association 2013). A further 16GW of new nuclear power capacity at eight sites around the UK is planned but it is not yet guaranteed to be online before 2023 (Nuclear AMRC 2014).
Gas
Gas power is significant in that it is the most suitable plant technology for reacting with intermittent sources of generation due to its short start-up times, when compared to coal and nuclear plants. However, as has been mentioned, it is also subject to price uncertainty. It is likely that the depicted shortfall from the above scenario will be taken up predominantly by gas-fired power for these reasons as well as the relatively short times to build new plant. It is also seen in 2008-12 that this technology was the main contributor to increased capacity.
Renewables
18.2GW of wind farms were under construction, consented or in planning as of 2013 (DECC 2012c) but assuming consents relative to historic figures, 2.7GW may not be continued. The total capacity required is equal to 23.47GW - 30% of total generating
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capacity - in 2020, based on the presented scenario’s calculation. After 2020, renewables contributions will remain at 30% of the electricity generated in this scenario. Tidal resources could supply in excess of 10% of total UK electricity (Sustainable Development Commission 2007) while wave resources are considerably greater, estimated at 50TWh/year – enough to meet around 14% of UK electricity demand (RenewableUK 2010). This however, in a pragmatic sense, is still speculation and as mentioned, wave and tidal projects have not been demonstrated on a commercial scale and in order to be conservative in this scenario no specific capacity is considered other than what could be assumed that would contribute to total renewables, meeting the 2020 EU targets.
Figure 3.5: Changes to UK Capacities over the next decade. (2008-12 from published data (DECC 2013) and 2012-23 taken using the assumptions detailed in the text,
including meeting EU targets for installed renewables)
It is important to realise that renewables will be unable to meet 2020 targets without adding approximately 2.1GW per year. There have been contrasting global projections for annual capacity increases of wind capacity. The International Energy Agency (IEA) suggest as little as 5% annually (although up from 2.2% in 2008 projections) in their reference scenario (IEA 2009; Figure 9.2), while the Energy Watch Group (EWG) suggested 30% was more realistic (Rechsteiner 2008). This is a large range and is difficult to relate to UK wind capacity increases. This scenario increases wind capacity linearly at 2.1.GW per annum based on meeting our renewable targets. A review of
0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 Installe d Capac ity (G W ) Electricity Shor8all Hydro Renewables Nuclear Gas-‐fired
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projects either under construction, consented or in planning, suggests Figure 3.5 is not unreasonable. Chapter 5 will also show how growth in wind power within the EU has exceeded most projections to date. Based on these figures, UK targets appear achievable. Optimists believe strongly that “wind power generation will be the same
volume as conventional plant types as soon as 2025 if historical growth of wind sector continues or construction of nuclear and coal plant types come to an end and natural gas plant types are used for peak demand only” (Peter & Lehmann 2008). There were
other suggestions for the likely build rate of wind power in the UK, expressed by Parsons Brinckerhoff who suggested a capacity build rate of 800MW per year (Parsons Brinckerhoff, 2009; Table 9.5.2). This estimation comes from wind farms installed in the UK in 2008, therefore it is based on real figures, but it is also now a historical figure and is below the annual increases now seen in the UK (DECC 2013). It is the legally binding EU targets that will drive the required increase through subsidy and political support. This is why it is assumed that 2.1GW is feasible. This compares similarly to the build rate of combined cycle gasification turbine power plant during the ‘dash for gas’ during the 1990s (Parsons Brinckerhoff 2009) with a lead-in time of 4 years as opposed to wind power’s 3 years, favouring wind.