UK Electricity Grid Report 2017
In 2017, Great Britain generated 301 TWh of electricity. Gas was the biggest single source at 39.7%. Renewables (wind, solar and hydro) supplied 20.4%, or 21.1% counting biomass, and each unit generated averaged 240gCO₂ per kWh. That made 2017 cleaner than 2016: carbon intensity fell 33.8 g on the year.
Automated summaryIn 2017, Great Britain's electricity grid generated 300.69 TWh, with gas remaining the single largest source at 39.7%, followed by nuclear at 21.8% and wind at 10.8%. Renewables comprising wind, solar and hydro accounted for 20.4% of generation, rising to 21.1% when biomass is included, while low carbon sources together supplied 42.9%. Coal fell to a 6.9% share, and the grid operated without any coal generation for 585 hours across the year, helping bring average carbon intensity down to 240 gCO2/kWh. The average wholesale price sat at £46.23/MWh, with prices turning negative for 20.5 hours over the period.
Renewables share
20.4%
21.1% incl. biomass
Low carbon share
42.9%
renewables + nuclear
Carbon intensity
240 g
per kWh · low 64 g, high 425 g
Generation
301 TWh
incl. estimated embedded wind and solar
Coal share
6.9%
585 coal-free hours
Peak wind output
9.7 GW
highest half-hour average
The 2017 generation mix, fuel by fuel
share of GB generation- Gas39.7% · 119.23 TWh
- Nuclear21.8% · 65.56 TWh
- Wind10.8% · 32.34 TWh
- Coal6.9% · 20.61 TWh
- Imports6.5% · 19.48 TWh
- Other4.1% · 12.25 TWh
- Solar3.5% · 10.45 TWh
- Hydro1.3% · 3.96 TWh
- Storage0.9% · 2.74 TWh
- Biomass0.7% · 2.22 TWh
Wholesale prices in 2017
market index (MID), volume-weighted across APX and N2EXThe average UK wholesale electricity price in 2017 was £46.23 per MWh on the market index (MID) basis. Prices were negative for 20.5 hours across the year. The most expensive half hour came on 17 May 2017 (settlement period 34) at £388.37 per MWh; the cheapest, £-24.06, came on 7 June 2017.
Average price
£46.23
per MWh, volume-weighted
Highest half hour
£388
17 May 2017, period 34
Lowest half hour
£-24.06
7 June 2017
Negative price hours
20.5
price below £0/MWh
Electricity supplied, 2009 to 2026
TWh per year, generation basis incl. estimated embedded wind and solar- 2009329 TWh
- 2010335 TWh
- 2011322 TWh
- 2012324 TWh
- 2013322 TWh
- 2014310 TWh
- 2015305 TWh
- 2016303 TWh
- 2017301 TWh
- 2018298 TWh
- 2019292 TWh
- 2020276 TWh
- 2021285 TWh
- 2022290 TWh
- 2023275 TWh
- 2024281 TWh
- 2025289 TWh
- 2026151 TWh
Britain supplies markedly less electricity than it did in 2009, even as the economy has grown: efficiency, LED lighting and offshored industry all pushed demand down while the mix decarbonised.
How 2017 compares
- Versus 2016: renewables +5 points, carbon intensity -33.8 g.
- Versus 2009, the first year on record: renewables up 17 points (from 3.4%), and each unit of electricity 46% cleaner (445 g to 240 g).
- Explore the neighbouring years: 2016 · 2018 or the full year-by-year table.
Cite this report
You are welcome to reuse the figures on this page with a link back. Suggested citation:
Purely Energy, "UK Electricity Grid Report 2017", purelyenergy.co.uk/grid-report/2017. Derived from NESO historic generation mix data.
2017 grid questions, answered
How green was UK electricity in 2017?
In 2017, wind, solar and hydro supplied 20.4% of GB generation (21.1% including biomass), low-carbon sources supplied 42.9%, and the average carbon intensity was 240 gCO2 per kWh.
What was the biggest source of UK electricity in 2017?
Gas was the largest single source in 2017, supplying 39.7% of GB generation. The full fuel-by-fuel breakdown is on this page.
How much coal did the UK burn for electricity in 2017?
Coal supplied 6.9% of GB generation in 2017 (20.61 TWh), and the grid ran coal-free for 585 hours.
What was the average UK wholesale electricity price in 2017?
The average UK wholesale electricity price in 2017 was £46.23 per MWh on the market index (MID) basis, volume-weighted across the year's half-hourly trading.
How many hours were UK power prices negative in 2017?
UK wholesale power prices (market index basis) were negative for 20.5 hours in 2017.
Use the data
Every figure on this page, as a CSV you can drop into a spreadsheet.
Basis: NESO historic generation mix (GB transmission generation plus estimated embedded wind and solar), aggregated by calendar year, energy-weighted. Renewables is NESO's wind + solar + hydro measure; the biomass-inclusive share is shown alongside. See the live version of this data on our real-time grid map and today's prices on wholesale market data.
Data comes from the Elexon Insights Solution (BMRS), the NESO Data Portal and the Carbon Intensity API, a project by the National Energy System Operator and the University of Oxford Department of Computer Science. Contains BMRS data © Elexon Limited copyright and database right 2026.
Energy decisions for the grid of 2026
The mix above sets the shape of wholesale prices. We turn it into procurement strategy for businesses across the UK, from fixed contracts to flexible purchasing.
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