Clean power by 2035 to meet climate targets says National Grid

Less than 1% unabated fossil fuels and at least 80% wind and solar in the power mix required

Tom Harrison

Electricity transition analyst

11 August 2021 | 4 min read

The UK is committed to achieving net-zero carbon emissions by 2050 and this year’s edition of National Grid ESO’s Future Energy Scenarios shows that a 2035 clean power sector driven by a massive expansion of renewables is now the benchmark for the UK if it is to reach this goal. All of National Grid’s scenarios which meet UK climate targets include less than 1% unabated fossil fuels by 2035 and generate 80% of their power from wind and solar. Achieving these levels of renewables requires significant action in the near term but will set the UK on a pathway to becoming a major exporter of clean power. The UK government should now commit to a clean power system by 2035 safe in the knowledge that this goal is achievable.

By 2035, fossil fuels will be just noise in the UK generation mix if the country is on track to meet its own climate targets. As this week’s new IPCC report demonstrates, removing fossil fuels from the power sector is the most important route to halving global emissions this decade. Ahead of COP26 in Glasgow, the government can again stand as a world leader by committing the country to deliver a clean power system by 2035.

Tom Harrison Analyst, Ember
Tom Harrison

Future Energy Scenarios 2021

In July, National Grid ESO published its annual Future Energy Scenarios (FES) using class-leading energy modelling to map out three credible pathways to decarbonising the UK economy. This year’s edition, FES 2021, updates its predecessor’s (FES 2020) pathways to reaching economy-wide net-zero carbon emissions by 2050.

All three scenarios meet the 2050 net-zero target through complete decarbonisation of the energy sector as well as road and rail transport and are also aided by emissions removals through bioenergy with carbon capture and storage (BECCS), direct air carbon capture and storage (DACCS) or land-use change. Although the three scenarios achieve this through different emphases on supply- or consumer-side transformation, all rely on significant decarbonisation through electrification. Consequently, by 2050, generation of renewable power from wind and solar increases by at least five-fold from 101 TWh in 2020 to between 563 TWh and 712 TWh in 2050.

Zero-carbon power by 2035

Of course this massive expansion in renewables generation has significant near term implications. Most notably, all three FES 2021 scenarios see the UK achieving an essentially zero-carbon power sector by 2035. This happens through the elimination of effectively all electricity generation from unabated fossil fuels, which fall from 33% to 0.98-0.46% of total electricity generation. Fossil fuels are replaced with renewables increasing the share of zero-carbon power from 67% to >99% of total generation by 2035. Wind and solar provide nearly all of this increase, accounting for 80% of total generation by 2035.

How does National Grid envision the 2035 energy mix?

➥Fossil Fuels

FES 2021 sees fossil fuel generation drop from 33% of total domestic generation (92 TWh) in 2020 to less than 1% (3-5 TWh) in 2035. Despite a near end to generation from fossil fuels, by 2035 significant unabated gas capacity of 9.8-30.4GW still remains in all scenarios to ensure security of power supply.


Renewables see a strong increase in capacity by 2035, primarily led by offshore wind which increases up to almost eight fold by 2035 (10.5 GW in 2020 and 56.8-76.2 GW in 2035). Onshore wind and solar also play an expanded role increasing up to 2.5 and 4.2 times respectively. Onshore wind rises from 12.7 GW in 2020 to 27.8-31.7 GW in 2035, while solar increases from 13.0 GW in 2020 to 37.1-57.2 GW in 2035.


The increase in renewables capacity is met with increased electricity storage capacity in all scenarios (3.5 GW in 2020 and 13.7-23.4 GW in 2035). Although the FES scenarios see a variety of storage solutions contributing to grid flexibility, including pumped hydro and vehicle-to-grid, battery storage is the dominant technology and accounts for the majority of the capacity increase.

➥Gas CCUS and hydrogen

Gas CCUS and hydrogen play a negligible role in power generation reflecting a status as purely grid-balancing technologies. They only marginally increase in capacity by 2035 (0-3.5GW and 2.9-6.6GW respectively).


The transition to clean power sees generation from unabated biomass fall to negligible levels after 2027 in all scenarios, coinciding with the government’s removal of support for converted coal-to-biomass plants.


Following the rapid expansion of wind and solar and increased interconnection capacity with Europe, the UK becomes a significant net exporter of electricity in all scenarios that meet the UK’s climate targets, reaching 65-111 TWh in 2035, equivalent to 15-20% of domestic generation.

Does BECCS risk polluting the zero-carbon target?

The phase out of unabated biomass does not spell the end for the involvement of biomass in the power sector. By 2035 all scenarios see the emergence of large-scale BECCS reaching 3.0-6.6 GW capacity. This is up to more than twice the total capacity of Drax – the world’s largest wood burning power plant – and several times larger than the first two units (1.3GW) of Drax’s proposed BECCS project. The scale and speed of BECCS deployment in FES reflects National Grid’s confidence in the ability of BECCS to deliver negative emissions. This confidence incentivises rapid deployment, relying on BECCS to remove carbon from the atmosphere as early as possible. The negative emissions generated by BECCS are not used to decarbonise the power sector but instead mitigate emissions from harder to decarbonise sectors.

Although its generation output and capacity are comparatively small when measured against wind and solar’s role in the future scenarios, relying on BECCS for negative emissions is extremely risky. BECCS is an unproven technology that relies upon the unreasonable and uncritical assumption that burning biomass for power is inherently carbon neutral. As a result BECCS may not deliver the negative emissions it promises or worse yet, actually contribute carbon emissions. It is also likely to be a highly costly technology that will demand considerable public subsidy to operate. FES 2021’s most ambitious scenario includes less BECCS capacity than the same scenario last year. Given the significant carbon and cost risks of BECCS, we would encourage National Grid to continue to minimise its involvement in future models and reports.

National Grid and the CCC agree: the power sector must be decarbonised by 2035

FES 2021 adds to a growing consensus on the necessary timeline for UK power sector decarbonisation. All of National Grid ESO’s net-zero scenarios rely on an effectively fully decarbonised power sector by 2035 to reach net-zero by 2050, which closely aligns with recommendations from the CCC’s Sixth Carbon Budget. There are slight differences: FES scenarios retain some unabated gas capacity on the grid in 2035 (and beyond), whereas the CCC calls for a complete phase-out of unabated gas power (subject to meeting security of supply) in the same time frame. However, the electricity generation from the remaining unabated gas in 2035 is negligible in the FES scenarios, reaffirming the emerging consensus that net-zero by 2050 means a decarbonised power system by 2035.

Although the FES 2021 scenarios are not predictions of what will happen, they are credible projections that show a 2035 clean power sector could happen. The IPCC’s report released this week has underlined the urgency with which we must tackle climate change. As the UK prepares to host this year’s pivotal COP26 talks, it can catalyse a global gas phase-out by making a firm commitment to clean power by 2035, just as the UK coal phase-out began an international trend. At home, the clean power commitment can accelerate the green industrial revolution and technological innovation that will take the country to net zero.