Electricity Grid Review 2025: Great Britain

January 1 - December 31, 2024 vs 2025

Data coverage: 366 days (2024), 365 days (2025)

1. Electricity Price (Day-Ahead, GBP/MWh)

Mean 2024

£72.5

Mean 2025

£80.5

+£8.0

Monthly Average Day-Ahead Price

GBP/MWh

20242025

Price-Carbon Correlation

Correlation coefficient: -0.68 (2024), -0.71 (2025). Strong negative correlation - higher renewable generation = lower prices, reflecting the merit order effect.

1.1 Daily Price Extremes

Based on daily average prices

Metric	2024	2025
Highest Daily Avg	£220.2 (Dec 12, 2024)	£259.2 (Jan 22, 2025)
Lowest Daily Avg	£6.8 (Apr 06, 2024)	£1.1 (Oct 04, 2025)
Negative Price Days	0	0
Negative Price Hours	141	190

1.2 Hourly Price Extremes

Metric	2024	2025
Highest Price	£491.0 (Dec 12, 2024 16:00)	£958.5 (Jan 22, 2025 17:00)
Lowest Price	£-28.2 (Apr 13, 2024 13:00)	£-30.5 (May 25, 2025 11:00)

1.3 Days by Price Range

Based on daily average prices

Range (£/MWh)	2024	2025	Δ
£0-50	34	33	-1
£51-100	305	281	-24
£101-150	25	46	+21
£151-200	1	3	+2
£201+	1	2	+1

1.4 Hours by Price Range

Based on hourly prices

Range (£/MWh)	2024	2025	Δ
Negative	141	190	+49
£0-50	1,152	869	-283
£51-100	6,548	5,926	-622
£101-150	870	1,600	+730
£151-200	40	75	+35
£201+	31	47	+16

1.5 Average Price by Hour of Day

2025 Average Price by Hour

£/MWh

1.6 Price Distribution (Hourly)

Price Distribution

Number of hours at each level

20242025

Negative Price Events

190 hours with negative prices across 33 days. Most negative: £-30.5/MWh.

Intraday Price Volatility

Average daily price swing: £68/MWh. Maximum single-day swing was £866/MWh on 2025-01-22 (low: £92, high: £958).

Notable monthly evolutions

⚠️ Jan-Feb 2025: Electricity prices were 71% higher than Jan-Feb 2024

Change: +71% vs 2024

Possible explanation: Extended Dunkelflaute (dark doldrums) conditions in early 2025 - a combination of cold weather and very low wind generation - forced Germany to rely heavily on coal and gas power plants. Wind output dropped to just 2.8 GW compared to a normal 19 GW capacity, causing wholesale prices to spike above €900/MWh at peak hours.

1.7 Multi-Level Price Heatmap

Price Heatmap

£/MWh

80.5 £/MWh yearly avg

hourly range: -31-959

Yearly

Monthly

Daily

Hourly

600

175

-250

2. Load

Load 2024

266.2 TWh

Load 2025

270.3 TWh

+1.5%

Production 2024

236.9 TWh

Production 2025

244.2 TWh

+3.1%

2.1 Average Load by Hour of Day

36.518.30

00:0006:0012:0018:0023:00

Load Pattern

Peak demand at 17:00 (36.5 GW). Minimum at 04:00 (23.0 GW).

2.2 Weekday vs Weekend

Weekday Average

31.7 GW

Weekend Average

28.8 GW

2.3 Net Load Pattern (Duck Curve)

Net Load Pattern (excl. Solar & Wind)

GW

Solar Integration Challenge

Evening ramp of 9.7 GW from belly (04:00) to evening peak (18:00). This requires flexible dispatchable generation or storage to meet rapidly increasing demand as solar output decreases.

2.4 Peak & Minimum Demand Records (2025)

Rank	Highest Load	Date	Lowest Load	Date
1	49059.6 GW	2025-01-09 17:00	16613.7 GW	2025-08-24 04:00
2	48233.0 GW	2025-01-10 11:00	16790.2 GW	2025-08-24 05:00
3	48059.3 GW	2025-01-10 10:00	17035.9 GW	2025-08-24 03:00

3. Production-Based vs Flow-Traced Carbon Intensity (gCO₂eq/kWh)

Key Insight

Production-based carbon intensity is 17.1g higher than flow-traced carbon intensity in 2024 (20.3g in 2025). This means Great Britain's imports are cleaner than domestic production, lowering the carbon footprint of consumed electricity.

Production-Based 2024

192.2 g

Production-Based 2025

196.2 g

+4.0

Flow-Traced 2024

175.0 g

Flow-Traced 2025

175.9 g

+0.9

3.1 Production Mix (Domestic Generation)

2024 Production

35%

31%

16%

8%

7%

2025 Production

36%

32%

14%

8%

8%

3.2 Flow-Traced Power Mix

2024 Flow-Traced

32%

27%

20%

7%

7%

6%

2025 Flow-Traced

33%

28%

18%

8%

7%

5%

Nuclear

Hydro

Wind

Solar

Biomass

Gas

Coal

Oil

Hydro Storage

Battery

3.4 Power Mix Comparison

Production vs Flow-Traced consumption by source

Source	Prod 2024	Flow-traced 2024	Prod 2025	Flow-traced 2025
Wind	34.9%	32.3%	35.5% (+0.6pp)	32.6% (+0.3pp)
Gas	30.7%	27.5%	32.0% (+1.3pp)	28.2% (+0.7pp)
Nuclear	16.2%	19.7%	14.1% (-2.1pp)	18.1% (-1.6pp)
Solar	6.7%	6.8%	7.8% (+1.1pp)	8.2% (+1.4pp)
Biomass	7.9%	7.2%	8.2% (+0.3pp)	7.4% (+0.2pp)
Hydro	1.5%	5.6%	1.4% (-0.1pp)	4.9% (-0.7pp)
Hydro Storage	1.4%	0.2%	1.0% (-0.4pp)	0.3% (+0.1pp)
Coal	0.7%	0.8%	0.0% (-0.7pp)	0.2% (-0.6pp)

3.5 Key Trend

Wind Share (Flow-Traced)

Great Britain's electricity consumption is led by ~32.6% wind. Hydro Storage saw the biggest growth from 0.2% to 0.3%.

4. Cross-Border Electricity Flows

Total Exports 2025

14.74 TWh

+43.5%

Total Imports 2025

43.17 TWh

-0.4%

Net Position 2025

-28.43 TWh

Great Britain: Net Electricity Importer

Great Britain imported a net 28.43 TWh in 2025.

4.1 2025 Gross Exports (Great Britain → Neighbor)

Total electricity exported to each country — with average carbon intensity

4.80 TWh

173g

2.46 TWh

172g

GB-NIR

2.32 TWh

174g

DK-DK1

2.23 TWh

185g

1.64 TWh

180g

0.62 TWh

163g

NO-NO2

0.42 TWh

119g

0.20 TWh

172g

GB-ORK

0.03 TWh

195g

4.2 2025 Gross Imports (Neighbor → Great Britain)

Total electricity imported from each country — with average carbon intensity

21.63 TWh

29g

NO-NO2

8.60 TWh

28g

DK-DK1

4.81 TWh

89g

3.78 TWh

162g

2.84 TWh

236g

0.30 TWh

221g

GB-NIR

0.14 TWh

262g

GB-ORK

0.04 TWh

14g

4.3 Net Position by Neighbor (2025)

Neighbor	Net (TWh)	Direction
IE	+4.51	Net Exporter
GB-NIR	+2.18	Net Exporter
IM	+0.20	Net Exporter
GB-ORK	-0.02	Net Importer
NL	-0.38	Net Importer
BE	-2.14	Net Importer
DK-DK1	-2.58	Net Importer
NO-NO2	-8.18	Net Importer
FR	-21.01	Net Importer

Positive = Great Britain is net exporter to that neighbor. Negative = Great Britain is net importer from that neighbor.

4.4 Flow Pattern by Hour of Day

Cross-Border Flow Pattern by Hour

MW (positive = export, negative = import)

Net ExportNet Import

Cross-Border Flow Timing

Peak exports at 05:00 (-1.5 GW avg). Peak imports at 11:00 (4.6 GW avg).

5. Carbon Intensity (gCO₂eq/kWh)

Mean 2024

175.0 g

Mean 2025

175.9 g

+0.9

Monthly Average Carbon Intensity

gCO₂eq/kWh (flow-traced)

20242025

5.1 Daily Records

Metric	2024	2025
Lowest Carbon Intensity	65.6 g (Apr 05, 2024)	70.2 g (Oct 26, 2025)
Lowest Fossil %	8.2% (Apr 05, 2024)	7.9% (May 29, 2025)
Highest Carbon Intensity	360.2 g (Dec 12, 2024)	348.0 g (Jan 20, 2025)
Highest Fossil %	68.7% (Dec 12, 2024)	65.1% (Jan 20, 2025)

5.2 Hourly Records

Metric	2024	2025
Lowest Carbon Intensity	44.1 g (Aug 29, 2024 10:00)	50.7 g (May 29, 2025 09:00)
Highest Carbon Intensity	384.4 g (Dec 12, 2024 06:00)	379.2 g (Jan 22, 2025 07:00)

5.3 Days Below Thresholds

Threshold	2024	2025	Δ
< 100 gCO₂eq/kWh	40	38	-2
< 200 gCO₂eq/kWh	250	243	-7
< 300 gCO₂eq/kWh	354	356	+2

5.4 Hours Below Thresholds

Threshold	2024	2025	Δ
< 100 gCO₂eq/kWh	1,727	1,780	+53
< 200 gCO₂eq/kWh	5,879	5,683	-196
< 300 gCO₂eq/kWh	8,298	8,328	+30

5.5 Average Carbon Intensity by Hour of Day

2025 Average Carbon Intensity by Hour

gCO₂eq/kWh

5.6 Carbon Intensity Distribution (Hourly)

Carbon Intensity Distribution

Number of hours at each level

20242025

Notable monthly evolutions

ℹ️ Apr 2025: Carbon intensity was 29% higher in Apr

Change: +29% vs Apr 2024

Possible explanation: Continued low wind conditions through spring 2025 kept carbon intensity elevated. Just 39 TWh of wind-powered electricity was produced from January to April - the lowest for that period since 2017, despite wind capacity increasing by 30% since then.

ℹ️ Aug 2025: Carbon intensity was 34% higher in Aug

Change: +34% vs Aug 2024

ℹ️ Nov 2025: Carbon intensity was 22% lower in Nov

Change: -22% vs Nov 2024

Golden Hours

1,621 hours with both low price (<£70/MWh) and low carbon intensity (<108 gCO₂eq/kWh).

5.7 Multi-Level Carbon Intensity Heatmap

Carbon Intensity Heatmap

gCO₂eq/kWh

175.9 gCO₂eq/kWh yearly avg

hourly range: 51-379

Yearly

Monthly

Daily

Hourly

1200

600

0

6. Renewable & Carbon-Free Energy (Flow-Traced)

Includes electricity exchanged with neighboring grids

Renewable 2024

51.3%

Renewable 2025

52.5%

+1.2pp

Carbon-Free 2024

70.7%

Carbon-Free 2025

70.3%

-0.4pp

Monthly Carbon-Free Share

% of consumption (renewable + nuclear)

20242025

6.1 Days Above Thresholds

Days with carbon-free share above threshold

Threshold	2024	2025	Δ
≥50% carbon-free	205	212	+7
≥60% carbon-free	98	115	+17
≥70% carbon-free	14	21	+7

6.2 Hours Above Thresholds

Hours with carbon-free share above threshold

Threshold	2024	2025	Δ
≥50% carbon-free	4,816	5,019	+203
≥60% carbon-free	2,795	3,139	+344
≥70% carbon-free	813	1,185	+372

6.3 Multi-Level Carbon-Free % Heatmap

Carbon-Free % Heatmap

70.3 % yearly avg

hourly range: 28-96

Yearly

Monthly

Daily

Hourly

100

50

0

Electricity Grid Review 2025: Great Britain

January 1 - December 31, 2024 vs 2025

Data coverage: 366 days (2024), 365 days (2025)

1. Electricity Price (Day-Ahead, GBP/MWh)

Mean 2024

£72.5

Mean 2025

£80.5

+£8.0

Monthly Average Day-Ahead Price

GBP/MWh

20242025

Price-Carbon Correlation

Correlation coefficient: -0.68 (2024), -0.71 (2025). Strong negative correlation - higher renewable generation = lower prices, reflecting the merit order effect.

1.1 Daily Price Extremes

Based on daily average prices

Metric	2024	2025
Highest Daily Avg	£220.2 (Dec 12, 2024)	£259.2 (Jan 22, 2025)
Lowest Daily Avg	£6.8 (Apr 06, 2024)	£1.1 (Oct 04, 2025)
Negative Price Days	0	0
Negative Price Hours	141	190

1.2 Hourly Price Extremes

Metric	2024	2025
Highest Price	£491.0 (Dec 12, 2024 16:00)	£958.5 (Jan 22, 2025 17:00)
Lowest Price	£-28.2 (Apr 13, 2024 13:00)	£-30.5 (May 25, 2025 11:00)

1.3 Days by Price Range

Based on daily average prices

Range (£/MWh)	2024	2025	Δ
£0-50	34	33	-1
£51-100	305	281	-24
£101-150	25	46	+21
£151-200	1	3	+2
£201+	1	2	+1

1.4 Hours by Price Range

Based on hourly prices

Range (£/MWh)	2024	2025	Δ
Negative	141	190	+49
£0-50	1,152	869	-283
£51-100	6,548	5,926	-622
£101-150	870	1,600	+730
£151-200	40	75	+35
£201+	31	47	+16

1.5 Average Price by Hour of Day

2025 Average Price by Hour

£/MWh

1.6 Price Distribution (Hourly)

Price Distribution

Number of hours at each level

20242025

Negative Price Events

190 hours with negative prices across 33 days. Most negative: £-30.5/MWh.

Intraday Price Volatility

Average daily price swing: £68/MWh. Maximum single-day swing was £866/MWh on 2025-01-22 (low: £92, high: £958).

Notable monthly evolutions

⚠️ Jan-Feb 2025: Electricity prices were 71% higher than Jan-Feb 2024

Change: +71% vs 2024

1.7 Multi-Level Price Heatmap

Price Heatmap

£/MWh

80.5 £/MWh yearly avg

hourly range: -31-959

Yearly

Monthly

Daily

Hourly

600

175

-250

2. Load

Load 2024

266.2 TWh

Load 2025

270.3 TWh

+1.5%

Production 2024

236.9 TWh

Production 2025

244.2 TWh

+3.1%

2.1 Average Load by Hour of Day

36.518.30

00:0006:0012:0018:0023:00

Load Pattern

Peak demand at 17:00 (36.5 GW). Minimum at 04:00 (23.0 GW).

2.2 Weekday vs Weekend

Weekday Average

31.7 GW

Weekend Average

28.8 GW

2.3 Net Load Pattern (Duck Curve)

Net Load Pattern (excl. Solar & Wind)

GW

Solar Integration Challenge

Evening ramp of 9.7 GW from belly (04:00) to evening peak (18:00). This requires flexible dispatchable generation or storage to meet rapidly increasing demand as solar output decreases.

2.4 Peak & Minimum Demand Records (2025)

Rank	Highest Load	Date	Lowest Load	Date
1	49059.6 GW	2025-01-09 17:00	16613.7 GW	2025-08-24 04:00
2	48233.0 GW	2025-01-10 11:00	16790.2 GW	2025-08-24 05:00
3	48059.3 GW	2025-01-10 10:00	17035.9 GW	2025-08-24 03:00

3. Production-Based vs Flow-Traced Carbon Intensity (gCO₂eq/kWh)

Key Insight

Production-Based 2024

192.2 g

Production-Based 2025

196.2 g

+4.0

Flow-Traced 2024

175.0 g

Flow-Traced 2025

175.9 g

+0.9

3.1 Production Mix (Domestic Generation)

2024 Production

35%

31%

16%

8%

7%

2025 Production

36%

32%

14%

8%

8%

3.2 Flow-Traced Power Mix

2024 Flow-Traced

32%

27%

20%

7%

7%

6%

2025 Flow-Traced

33%

28%

18%

8%

7%

5%

Nuclear

Hydro

Wind

Solar

Biomass

Gas

Coal

Oil

Hydro Storage

Battery

3.4 Power Mix Comparison

Production vs Flow-Traced consumption by source

Source	Prod 2024	Flow-traced 2024	Prod 2025	Flow-traced 2025
Wind	34.9%	32.3%	35.5% (+0.6pp)	32.6% (+0.3pp)
Gas	30.7%	27.5%	32.0% (+1.3pp)	28.2% (+0.7pp)
Nuclear	16.2%	19.7%	14.1% (-2.1pp)	18.1% (-1.6pp)
Solar	6.7%	6.8%	7.8% (+1.1pp)	8.2% (+1.4pp)
Biomass	7.9%	7.2%	8.2% (+0.3pp)	7.4% (+0.2pp)
Hydro	1.5%	5.6%	1.4% (-0.1pp)	4.9% (-0.7pp)
Hydro Storage	1.4%	0.2%	1.0% (-0.4pp)	0.3% (+0.1pp)
Coal	0.7%	0.8%	0.0% (-0.7pp)	0.2% (-0.6pp)

3.5 Key Trend

Wind Share (Flow-Traced)

Great Britain's electricity consumption is led by ~32.6% wind. Hydro Storage saw the biggest growth from 0.2% to 0.3%.

4. Cross-Border Electricity Flows

Total Exports 2025

14.74 TWh

+43.5%

Total Imports 2025

43.17 TWh

-0.4%

Net Position 2025

-28.43 TWh

Great Britain: Net Electricity Importer

Great Britain imported a net 28.43 TWh in 2025.

4.1 2025 Gross Exports (Great Britain → Neighbor)

Total electricity exported to each country — with average carbon intensity

4.80 TWh

173g

2.46 TWh

172g

GB-NIR

2.32 TWh

174g

DK-DK1

2.23 TWh

185g

1.64 TWh

180g

0.62 TWh

163g

NO-NO2

0.42 TWh

119g

0.20 TWh

172g

GB-ORK

0.03 TWh

195g

4.2 2025 Gross Imports (Neighbor → Great Britain)

Total electricity imported from each country — with average carbon intensity

21.63 TWh

29g

NO-NO2

8.60 TWh

28g

DK-DK1

4.81 TWh

89g

3.78 TWh

162g

2.84 TWh

236g

0.30 TWh

221g

GB-NIR

0.14 TWh

262g

GB-ORK

0.04 TWh

14g

4.3 Net Position by Neighbor (2025)

Neighbor	Net (TWh)	Direction
IE	+4.51	Net Exporter
GB-NIR	+2.18	Net Exporter
IM	+0.20	Net Exporter
GB-ORK	-0.02	Net Importer
NL	-0.38	Net Importer
BE	-2.14	Net Importer
DK-DK1	-2.58	Net Importer
NO-NO2	-8.18	Net Importer
FR	-21.01	Net Importer

Positive = Great Britain is net exporter to that neighbor. Negative = Great Britain is net importer from that neighbor.

4.4 Flow Pattern by Hour of Day

Cross-Border Flow Pattern by Hour

MW (positive = export, negative = import)

Net ExportNet Import

Cross-Border Flow Timing

Peak exports at 05:00 (-1.5 GW avg). Peak imports at 11:00 (4.6 GW avg).

5. Carbon Intensity (gCO₂eq/kWh)

Mean 2024

175.0 g

Mean 2025

175.9 g

+0.9

Monthly Average Carbon Intensity

gCO₂eq/kWh (flow-traced)

20242025

5.1 Daily Records

Metric	2024	2025
Lowest Carbon Intensity	65.6 g (Apr 05, 2024)	70.2 g (Oct 26, 2025)
Lowest Fossil %	8.2% (Apr 05, 2024)	7.9% (May 29, 2025)
Highest Carbon Intensity	360.2 g (Dec 12, 2024)	348.0 g (Jan 20, 2025)
Highest Fossil %	68.7% (Dec 12, 2024)	65.1% (Jan 20, 2025)

5.2 Hourly Records

Metric	2024	2025
Lowest Carbon Intensity	44.1 g (Aug 29, 2024 10:00)	50.7 g (May 29, 2025 09:00)
Highest Carbon Intensity	384.4 g (Dec 12, 2024 06:00)	379.2 g (Jan 22, 2025 07:00)

5.3 Days Below Thresholds

Threshold	2024	2025	Δ
< 100 gCO₂eq/kWh	40	38	-2
< 200 gCO₂eq/kWh	250	243	-7
< 300 gCO₂eq/kWh	354	356	+2

5.4 Hours Below Thresholds

Threshold	2024	2025	Δ
< 100 gCO₂eq/kWh	1,727	1,780	+53
< 200 gCO₂eq/kWh	5,879	5,683	-196
< 300 gCO₂eq/kWh	8,298	8,328	+30

5.5 Average Carbon Intensity by Hour of Day

2025 Average Carbon Intensity by Hour

gCO₂eq/kWh

5.6 Carbon Intensity Distribution (Hourly)

Carbon Intensity Distribution

Number of hours at each level

20242025

Notable monthly evolutions

ℹ️ Apr 2025: Carbon intensity was 29% higher in Apr

Change: +29% vs Apr 2024

ℹ️ Aug 2025: Carbon intensity was 34% higher in Aug

Change: +34% vs Aug 2024

ℹ️ Nov 2025: Carbon intensity was 22% lower in Nov

Change: -22% vs Nov 2024

Golden Hours

1,621 hours with both low price (<£70/MWh) and low carbon intensity (<108 gCO₂eq/kWh).

5.7 Multi-Level Carbon Intensity Heatmap

Carbon Intensity Heatmap

gCO₂eq/kWh

175.9 gCO₂eq/kWh yearly avg

hourly range: 51-379

Yearly

Monthly

Daily

Hourly

1200

600

0

6. Renewable & Carbon-Free Energy (Flow-Traced)

Includes electricity exchanged with neighboring grids

Renewable 2024

51.3%

Renewable 2025

52.5%

+1.2pp

Carbon-Free 2024

70.7%

Carbon-Free 2025

70.3%

-0.4pp

Monthly Carbon-Free Share

% of consumption (renewable + nuclear)

20242025

6.1 Days Above Thresholds

Days with carbon-free share above threshold

Threshold	2024	2025	Δ
≥50% carbon-free	205	212	+7
≥60% carbon-free	98	115	+17
≥70% carbon-free	14	21	+7

6.2 Hours Above Thresholds

Hours with carbon-free share above threshold

Threshold	2024	2025	Δ
≥50% carbon-free	4,816	5,019	+203
≥60% carbon-free	2,795	3,139	+344
≥70% carbon-free	813	1,185	+372

6.3 Multi-Level Carbon-Free % Heatmap

Carbon-Free % Heatmap

70.3 % yearly avg

hourly range: 28-96

Yearly

Monthly

Daily

Hourly

100

50

0