The UK's power output will be 70-80pc renewable by the end of this decade under all scenarios modelled for the government's net zero strategy, although gas-fired capacity will remain "crucial" for security of supply.
"From 2030 onwards renewable generation makes up around 70-80pc of domestic generation in all four scenarios" examined in an annex to the strategy, published today. The document models the UK's generation mix under its legally-binding target to reach net zero emissions by 2050, based on both lower and higher power demand scenarios — of 575TWh and 765TWh by mid-century, respectively — and the deployment or not of hydrogen. The scenarios are "indicative of what a future energy generation mix may look like rather than prescriptive forecasts".
Renewable generation rises to either 480TWh or 580TWh by 2050 without hydrogen and 450TWh or 570TWh with assumed hydrogen capacity of 20-25GW, generating 25-30TWh of electricity.
This includes 36-65GW more offshore wind capacity and 12-38GW more onshore wind capacity, reduced by 8GW and 5-7GW, respectively, in scenarios with hydrogen deployment. Solar capacity is assumed to be similar to the baseline "due to higher levels of merchant build in the baseline", but would be 5-9GW less with hydrogen.
The high proportion of renewables in the generation mix will make the UK a net power exporter to Europe from 2030 under all scenarios, the modelling finds, with net exports reaching 40-70TWh in 2050.
Around 90-93pc of domestic power output will be "low carbon" by 2030 under all scenarios, rising to more than 99pc by 2035.
The government sees nuclear generation rising in all cases, reaching 85TWh in 2050 under the lower demand scenarios and 175-190TWh in the event of higher demand, up by 50-150TWh compared with the baseline. This entails a 7-21GW increase in nuclear capacity in addition to the planned 3.2GW Hinkley Point C plant, and would be only a maximum of 1.6GW lower with hydrogen deployment.
Security of supply
All scenarios show a rise in gas-fired capacity to "ensure that the system can still meet security of supply constraints", to 70-100GW in 2050 without hydrogen and to 50-90GW with hydrogen, from 35GW in 2020.
Gas carbon capture, utilisation and storage will "increase significantly" to 40-70TWh by mid-century, representing an increase of 11-21GW in capacity, or 2GW less with hydrogen.
But unabated gas output "falls throughout the modelled period", with fleet average unabated gas load factors below 1pc in all scenarios from 2035 and natural gas meeting less than 1pc of total generation by 2050.
A House of Lords committee report published last week concluded that a lack of policy detail in the government's net zero strategy must be urgently addressed to ensure the country receives the investment required to meet its climate targets.
Three legal challenges launched against the strategy were last week granted permission to be heard together in a full hearing at the UK High Court.
UN secretary general Antonio Guterres yesterday called for a "prompt, well-managed transition to renewables" globally. "Fossil fuels are a dead end — for our planet, for humanity and for economies," he said.
