Modelling as part of the government’s long-awaited energy white paper shows that wind and solar generation could more than quadruple by 2050.
The modelling – which aimed to help the government understand the potential impact on system costs of reducing carbon emissions at different levels of demand, using different combinations of generating and storage technologies – looked at a range of scenarios in 2050, including with and without hydrogen and low (575TWh) and high demand scenarios (672TWh).
It identified 2050 capacity ranges for low carbon technologies that are deployable at scale, placing solar in the 15-120GW range, offshore wind between 40-120GW and onshore wind between 15-60GW.
It found that all low cost solutions include significant levels of wind and solar, with electricity system costs lowest when carbon intensity is between 5-25gCO2/kWh.
It did, however, find that all low-cost solutions also require other forms of low-carbon generation to provide resilience during extended periods of low wind and solar irradiation. The modelled options to provide this were nuclear, gas generation with carbon capture usage and storage (CCUS) and short-term dispatchable generation from unabated gas and/or low carbon hydrogen.
Overall, the government concluded that there is no single optimal technology mix. It said that many capacity mixes can meet different carbon emissions levels at low cost, and that this is true for all levels of demand modelled.
The amount of decarbonisation that can be achieved is influenced by the volume of hydrogen, new nuclear and CCUS, however. In the scenario without hydrogen, new nuclear beyond Sizewell C and Hinkley Point C or gas carbon capture usage and storage (CCUS), there were significant limits on the amount of decarbonisation that could be achieved as well as increases in system costs of decarbonisation.
This, it said, is because the additional renewable capacity required to replace unabated gas generation during periods of low renewable output either increases systems costs more than using additional nuclear and/or gas CCUS to do the same thing, or is not achievable within the build limits used in its modelling.
Curtailment will also remain a problem, with the level of curtailment increasing across all scenarios as the volume of renewables in the generation mix increases.
In the hydrogen scenario, curtailment is lower because of the generally lower volumes of renewable generation required, and in scenarios including within day storage and demand side response curtailment is also reduced.
It can be further reduced by the deployment of longer-term storage technologies, although these are not included within the modelling.
Storage was modelled, however, alongside interconnection and demand side response to determine the importance of flexibility in 2050.
A combination of demand side response, battery storage and interconnection was found to significantly reduce the system costs compared to scenarios with extremely low levels of flexibility. The example of the high demand scenario without hydrogen was given, where there is a reduction of up to £12 billion per year at a carbon intensity of 5gCO2/kWh.
An in-depth look at the policy measures revealed in the energy white paper can be read here.