UK low-carbon electricity generation stalled in 2019, says Carbon Brief


GENERATION of electricity from low-carbon sources in the UK stalled in 2019, new analysis by Carbon Brief shows.

Low-carbon electricity output from wind, solar, nuclear, hydro and biomass rose by just 1 terawatt hour (less than 1%) in 2019.

It represents the smallest annual increase in a decade, where annual growth averaged 9TWh.

According to Carbon Brief, this growth will need to double in the 2020s to meet UK climate targets while replacing old nuclear plants as they retire.

Some 54% of UK electricity generation in 2019 came from low-carbon sources, including 37% from renewables and 20% from wind alone.

A record-low 43% was from fossil fuels, with 41% from gas and just 2% from coal, also a record low.

In 2010, fossil fuels generated 75% of the total.

Carbon Brief’s analysis of UK electricity generation in 2019 is based on figures from BM Reports and the Department for Business, Energy and Industrial Strategy.

The numbers differ from those published earlier in January by National Grid, which were for electricity supplied in Great Britain only (England, Wales and Scotland, but excluding Northern Ireland), including via imports from other countries.


The nominal 100gCO2/kWh target for 2030 was set in the context of the UK’s less ambitious goal of cutting emissions to 80% below 1990 levels by 2050.

Now that the UK is aiming to cut emissions to net-zero by 2050, that 100gCO2/kWh indicator is likely to be the bare minimum.

Even so, it would require a rapid step up in the pace of low-carbon expansion, compared to the increases seen over the past decade, Carbon Brief says.

On average, low-carbon generation has risen by 9TWh each year in the decade since 2010 – including a rise of just 1TWh in 2019.

According to Carbon Brief, given scheduled nuclear retirements and rising demand expected by the Committee on Climate Change, with some electrification of transport and heating, low-carbon generation would need to increase by 15TWh each year until 2030, just to meet the benchmark of 100gCO2/kWh.

For context, the 3.2 gigawatt (GW) Hinkley C new nuclear plant being built in Somerset will generate around 25TWh once completed around 2026.

The world’s largest offshore windfarm, the 1.2GW Hornsea One scheme off the Yorkshire coast, will generate around 5TWh each year.

The new Conservative government is targeting 40GW of offshore wind by 2030, up from today’s figure of around 8GW.

If policies are put in place to meet this goal, then it could keep power sector emissions below 100gCO2/kWh, depending on the actual performance of the windfarms built.

However, new onshore wind and solar, further new nuclear or other low-carbon generation, such as gas with carbon capture and storage, is likely to be needed if demand is higher than expected, or if the 100gCO2/kWh benchmark is too weak in the context of net-zero by 2050.

Looking more closely at UK electricity generation in 2019, Carbon Brief’s analysis shows why there was so little growth for low-carbon sources compared to the previous year.

There was another increase for wind power in 2019 (up 8TWh, 14%), as several large new windfarms were completed including the 1.2GW Hornsea One project in October and the 0.6GW Beatrice offshore windfarm in Q2 of 2019.

However, this was offset by a decline for nuclear (down 9TWh, 14%), due to ongoing outages for reactors at Hunterston in Scotland and Dungeness in Kent.

(Analysis of data held by trade organisation RenewableUK suggests some 0.6GW of onshore wind capacity also started operating in 2019, including the 0.2GW Dorenell scheme in Moray, Scotland.)

As a result of these movements, the UK’s windfarms overtook nuclear for the first time ever in 2019, becoming the country’s second-largest source of electricity generation.

The UK’s currently suspended nuclear plants are due to return to service in January and March, according to operator EDF, the French state-backed utility firm.

However, as noted above, most of the UK’s nuclear fleet is set to retire during the 2020s, with only Sizewell B in Suffolk due to still be operating by 2030.

Hunterston is scheduled to retire by 2023 and Dungeness by 2028.

Set against these losses, the UK has a pipeline of offshore windfarms, secured via “contracts for difference” with the government, at a series of auctions.

The most recent auction, in September 2019, saw prices below £40 per megawatt hour – similar to current wholesale electricity prices.

However, the capacity contracted so far is ‘not sufficient’ to meet the government’s target of 40GW by 2030, meaning further auctions – or some other policy mechanism – will be required.

As well as the switch between wind and nuclear, 2019 also saw coal fall below solar for the first time across a full year after it suffered another 60% reduction in electricity output.

Just six coal plants remain in the UK, with Aberthaw B in Wales and Fiddlers Ferry in Cheshire closing in March.

Coal accounted for just 2% of UK generation in 2019, the lowest share since centralised electricity supplies started to operate in 1882.

The fuel met 40% of UK needs as recently as 2012, but has plummeted due to falling demand, rising renewables, cheaper gas and higher CO2 prices.

The reduction in average coal generation hides the fact that the fuel is now often not required at all to meet the UK’s electricity needs.

The 83 days in 2019 with zero coal generation amount to nearly a quarter of the year and include the record-breaking 18-day stretch without the fuel.

Notably, overall UK electricity generation fell by another 9TWh in 2019 (3%), bringing the total decline to 58TWh since 2010.

This is equivalent to more than twice the output from the Hinkley C scheme being built in Somerset.

As Carbon Brief explained last year, falling demand has had a similar impact on electricity-sector CO2 emissions as the increase in output from renewables.

This is illustrated by the fact that the 9TWh reduction in overall generation translated into a 9TWh (6%) cut in fossil-fuel generation during 2019, with coal falling by 10TWh and gas rising marginally.

As fossil-fuel output and overall generation have declined, the UK’s renewable sources of electricity have continued to increase.

Their output has risen nearly five-fold in the past decade and their share of the UK total has increased from 7% in 2010 to 37% in 2019.

As a result, the UK’s increasingly renewable grid is seeing more minutes, hours and days during which the likes of wind, solar and biomass collectively outpace all fossil fuels put together.

There were also four months in 2019 when renewables generated more of the UK’s electricity than fossil fuels: March, August, September and December.

The first-ever such month came in September 2018 and more are ‘certain to follow.’

National Grid is aiming to be able to run the system without fossil fuels by 2025, at least for short periods.

At present, it sometimes has to ask windfarm operators to switch off and gas plants to start running in order to keep the electricity grid stable.

Notably biomass accounted for 11% of UK electricity generation in 2019, nearly a third of the total from all renewables.

Some two-thirds of the biomass output is from “plant biomass”, primarily wood pellets burnt at Lynemouth in Northumberland and the Drax plant in Yorkshire.

The remainder was from an array of smaller sites based on landfill gas, sewage gas or anaerobic digestion.

Energy UK’s interim chief executive Audrey Gallacher, responded to Carbon Brief’s analysis by saying: “While these figures show just how much progress the energy sector has made in moving to cleaner sources of power and reducing emissions over the past few years – they are also a stark reminder of how much further and faster we have to go with the net-zero target in place.

“The amount of low carbon power produced has doubled over the last decade but we need to go above and beyond that to keep pace with our climate change targets, especially with overall demand set to increase – rather than falling as it has done in recent years.

“This underlines the urgency of increasing all forms of low carbon generation – and why we need to see Energy White Paper as soon as possible with action and policies that can enable the required investment and innovation to make this happen.“

Read the whole analysis by Carbon Brief here.