Government analysis suggests we might need up to 40GW of firm power – nuclear or power plants with carbon capture and storage by 2050. On the other hand a growing number of studies suggest that with flexibility and ever cheaper renewables it is perfectly possible to run our energy system on 100% renewables.
According to The Times, a leaked Government analysis suggests that Britain needs to build a fleet of nuclear or carbon-capture power plants equivalent to a dozen Hinkley Point Cs – up to 40GW of non-intermittent low carbon power stations to hit climate change targets. In its consultation on the nuclear funding model the Government said that while wind and solar energy would provide the majority of low-carbon capacity in 2050, there would still be a role for firm power supplies available when the wind doesn’t blow or the sun doesn’t shine.
Carbon Brief says the idea that electricity from nuclear and CCS will be required to get to net-zero is broadly in line with advice from the Committee on Climate Change (CCC) and some other research, whereas the National Infrastructure Commission (NIC) recommended a focus on renewables instead.
Unfortunately, the government’s justification appears to rest on model simulations run internally, which have not been published. The lack of transparency makes this analysis impossible to judge, says Michael Liebreich, founder of and now senior contributor to Bloomberg New Energy Finance. He told Carbon Brief:
“Any case for ‘firm’ power is essentially valueless without knowing the detail of the assumptions. Firm power which cannot be switched off when you don’t need it will be as much of a problem as variable power which cannot be switched on when you do. What is called for is flexibility, in huge quantities and of all types. Does the nuclear power in the government model provide it? We just aren’t told.”
Recent Committee on Climate Change (CCC) advice on reaching net-zero broadly supports the internal BEIS analysis but it includes a wider range of sources with different characteristics and levels of flexibility. The CCC’s ‘Further Ambition’ scenario, for instance, sees low-carbon sources providing 100% of power generation in 2050, through a mixture of variable renewables (57%), firm low-carbon power like nuclear or plants fitted with carbon capture and storage (38%) and decarbonised gas such as hydrogen (5%). But as we point out in nuClear News No.118 the reason for the view on firm power in this analysis seems to boil down to cost.
CCC says you can only go so far with the proportion of our energy supplied by renewables before costs start to rise. Yet the CCC doesn’t have a good record of estimating future energy costs. Back in 2008, it estimated that offshore and onshore wind costs would to be around £88/MWh and £76/MWh, respectively, by 2020 (expressed in 2008 prices). And it suggested that the potential for emissions reductions from solar PV was ‘very small’ within the first three budget periods, because of the high cost. In fact offshore wind generation dropped to under £65/MWh in 2017, and onshore wind would be around £46/MWh and the cost of installing new solar PV capacity is now around £56/MWh. It currently expects to see nuclear costs fall by 28% by 2050, which given past experience seems highly unlikely.
The other thing which the CCC has been bad at forecasting is electricity demand. In 2008 it expected that electricity demand would continue to increase overall, but demand has actually dropped. The CCC now expects a doubling of demand by 2050 due to extensive electrification of heat and transport. As we have reported here many times, the incoming Conservative-LibDem Coalition Government of 2010 was officially planning on the basis of a doubling or possibly even a tripling of electricity consumption by 2050. The 2005 Energy White Paper was expecting that by 2020 electricity consumption would have increased by 15%. In reality it has decreased by 16%. Nowadays primary energy demand is expected to continue falling by a further 11% by 2025. But after that projections revert to the bad old days. Within ten years Government forecasters expect consumption to be 2% more than today. As we point out in nuClear News No.118, it is becoming increasingly clear that car use will still need to be curbed even when all vehicles are powered by clean electricity, In nuClear News No.117 we looked at a report which said the increase in demand as a result of the electrification of transport may only be very limited and won’t dent the trends towards reduced electricity consumption.
Forecasting the impact of heat decarbonisation on electricity demand is much more complex. CCC says low-carbon hydrogen cannot be produced in large enough quantities to completely replace natural gas but this view is being challenged by the falling cost of renewables combined with the significant cost reduction potential of power-to-gas technology which could lead to much cheaper electrolytic hydrogen production than many have previously thought. Energy commentator Chris Goodall told Carbon Brief that “Cost competitive hydrogen from renewables makes full decarbonisation possible through power-to-gas and power-to-liquids.” German think thank Energy Brainpool claimed hydrogen produced by surplus wind and solar energy could be cheaper than natural gas as an energy source itself by the 2030s. And in the absence of a final decision on the decarbonisation of the gas grid energy efficiency measures, which could save around 130TWh, would be a no regrets option.
The BEIS assertion that up to 40GW of firm power will be “required” by 2050 is more clearly at odds with the views of the National Infrastructure Commission (NIC), which said last year that a focus on renewables “looks like a safer bet than constructing multiple new nuclear plants”. The NIC also gave short shrift to small nuclear plants (“their benefits remain speculative”) and CCS in the power sector (“unlikely to form part of a cost competitive generation mix”).
As Doug Parr, Chief Scientist at Greenpeace, points out there are a number of studies which show that a 100% renewable energy system is deliverable. The myth that a very high level of renewables can’t be integrated into the electric grid is being demolished by the clean tech and battery storage revolution. “By 2040, renewables make up 90% of the electricity mix in Europe, with wind and solar accounting for 80%,” according to projections by Bloomberg New Energy Finance (BNEF) in their annual energy outlook. “Cheap renewable energy and batteries fundamentally reshape the electricity system,” explains BNEF. Since 2010, wind power globally has dropped 49% in cost. Both solar and battery prices have plummeted 85%.
Mark Jacobson and his team from Stanford University, reckon that 100% of all global energy can come from renewable sources (with biomass excluded) by 2050 with full grid balancing. A new report by LUT University in Finland and the Energy Watch Group (EWG) in Germany outlines a cross-sector, global 100% renewable energy system.
An article published in Energy in May found that 180 studies on 100% renewables had been published since 2004. The authors of that paper say that six months later the number has jumped to 280.