2050 and all that
The Department of Energy and Climate Change has produced a new DIY energy supply-and-demand model, running up to 2050, developed under the supervision of Prof. David MacKay, DECC’s chief scientific advisor. You can try it out: http://2050-calculator-tool.decc.gov.uk/.
It allows you to vary the energy supply mix so as to try to meet emission targets in line with various possible demand patterns, including charging electric car batteries overnight. Following the line adopted in earlier DECC scenarios, what emerges is that it’s hard to stay in balance and get emissions down, without nuclear and Carbon Capture and Storage (CCS). The model tests the ability of the chosen supply mix to meet demand during a five-day anticyclone, with five days of low wind output and an increase in heating demand associated with the cold weather. But there are ways to balance variations like this, and the DECC report on ‘2050 energy pathways’, which sets the model in context, does explore some of these options.
Even so, it concludes that, if CCS is not widely used, ‘because of the large amount of renewables in this pathway, the challenges of balancing the electricity grid in the event of a five-day peak in heating and a drop in wind are more substantial. We would need a very significant increase in energy storage capacity, demand shifting and interconnection, together with 5GW of fossil-fuel-powered standby generation that would be inactive for most of the year.’ And if nuclear was not used, ‘the challenges of balancing the electricity grid are very substantial: we would need an extremely substantial increase in storage, demand shifting and interconnection’. By contrast ‘without renewables in the system, it is easier to balance the electricity grid and no additional back-up capacity beyond what exists today is required’. Nuclear then dominates, and, DECC seems to say, that path gives lowest overall costs long term.
Not everyone may agree with that. Indeed, Chris Huhne, the new Lib Dem Energy and Climate Change Secretary of State, is on record as saying that nuclear economics means that it will need state support to be competitive – something he and the coalition government were not prepared to provide. A recent version of this view was his response to Lord Marlands statement on behalf of the government that ‘there should be no dramatic increase’ in current plans for around 14GW of on land wind power. Defending wind, Huhne commented: ‘We have seen that with onshore wind, whose cost has come down dramatically precisely because of the encouragement of the public sector. I am afraid that the same argument cannot be made for nuclear power, which has been around for a long time. It is not an infant industry, but an established and mature one and it can and should compete on that basis, along with all other comers.’
However he seems to have been under pressure to back nuclear none the less. In a letter to The Financial Times (4 Aug) he said: ‘Given our policy framework, and the outlook for oil, gas and carbon prices, I am nevertheless confident that there will be new nuclear power as planned by 2018.’
He went on: ‘What nuclear will not have – and this is common across all three parties in Britain – is public subsidy specific to the industry.’ But there will – or could – be a susbsidy, in all but name, in the form of a floor price for carbon, which will benefit all non and low carbon options.
So what could actually emerge? DECC’s 2050 Pathways are not based on funding or support programmes, but simply offer four different ‘levels’ of possible technical response – from more or less none (1) to the absolute maximum (4), and then uses that as a basis for assembling a range of pathways with different mixes on both the supply and demand side, on the way to 2050.
Focusing here just on the supply side, on land wind comes out reasonably well with, by 2050, at Level 2, it being assumed that there could be 20 GW in place (delivering 55TWh of electricity then); at Level 3, 32GW (delivering 84TWh) and at the maximum Level 4, 50GW (132TWh). But offshore wind does much better – 60GW (delivering 184TWh) at Level 2,100GW (307TWh) at Level 3 and a massive 140 GW (430 TWh) at level 4. Wave/tidal stream devices do quite well at, respectively, 11.5GW (delivering 25TWh), 29 GW (68 TWh) and, at maximum, 58 GW (139 TWh), with wave leading tidal currents up to Level 4, when wave is put at 70TWh, tidal stream at 69TWh. But Tidal Range projects (barrages and lagoons) only manage, respectively, 1.7GW (3.4TWh), 13 GW (6TWh), and 20 GW (40 TWh) at Level 4 – significantly less than either wave or tidal stream in each case.
PV solar comes out of almost nowhere to yield, by 2050, 80 TWh at Level 3 and a massive 140 TWh at Level 4, although DECC is at pains to point out that the latter is very ambitious, expansion of this scale presenting ‘an unprecedented challenge’. In addition, small-scale wind only delivers 8.6 TWh/yr max, while geothermal reaches just 5 GW by 2030 at Level 4, and hydro moves up to 4 GW in Level 4.
More radically, by 2050, there are 140 TWh of imports from Concentrating Solar Power in desert areas, covering 5000 sq km, in level 4. It’s assumed that the UK’s share of this is 20%. There are also some imports of biomass – at the maximum, around 135 TWh each of wet and dry biofuels, by 2050.
In terms of grid balancing for variable renewables, DECC notes that, being relatively inflexible, neither nuclear or CCS can be relied on for very large balancing capacity. So it looks to others options – energy storage, new grid interconnections to and from the continent, and flexibility (e.g. by using the proposed electric vehicles (EVs) or plug-in hydbrid electric vehicles (PHEV) car battery fleet as an overnight store). At Level 3 the storage capacity peak output increases to 7 GW by 2050. Interconnection increases to 15 GW, and around a half of all EVs and PHEVs have a shiftable electricity demand capacity. At Level 4, storage capacity peak output reaches 20 GW, interconnection 30 GW; and 75% of all EVs’ and 90% of all PHEVs’ storage capacity are utilised for shifting demand.
Finally there’s nuclear. While at Level 1 it is assumed that ‘the Government no longer wishes to take new nuclear forward and that a lack of clarity over planning and licensing timescales would lead to no planning applications coming forward and potentially the suspension of activities at sites where planning applications had been submitted’. At Level 2 there would be ‘continued government and public support for new nuclear and that the facilitative actions would progress’, with a total capacity of 39 GW at 2050 delivering 275 TWh of electricity per year with a build rate of just over 1GW/year. (Interestingly, by comparison, it notes that in Germany in recent years the build rate for wind has averaged around 2.1 GW/year.)
At Level 3, a nuclear build rate of 3 GW/year is achievable from 2025, leading to 90 GW at 2050 (633 TWh). And at Level 4 we move from a build rate of 3 GW/yr up to 2025 to a max of 5 GW/yr thereafter, with government interventions being needed, so that 146 GW in reached at 2050, delivering 1025 TWh. But we couldn’t do that by ourselves – we would need overseas help!
Looking 40 years ahead is risky and hard to cost, but it’s a brave effort, especially as it also tries to cover a range of heat suppliers, like solar, and end-use sectors, including transport. There is a call for evidence and there will no doubt be plenty of debate on the details and the viability and desirability of some of the Level 4 suggestions, not least of 146GW of nuclear!
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