Electricity Grid Review 2025: Bulgaria

January 1 - December 31, 2024 vs 2025

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

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

Mean 2024

€104.4

Mean 2025

€106.4

+€2.0

Monthly Average Day-Ahead Price

EUR/MWh

20242025

Price-Carbon Correlation

Correlation coefficient: -0.24 (2024), -0.51 (2025). Moderate correlation between price and carbon intensity.

1.1 Daily Price Extremes

Based on daily average prices

Metric	2024	2025
Highest Daily Avg	€348.2 (Dec 12, 2024)	€252.5 (Jan 15, 2025)
Lowest Daily Avg	€20.7 (Apr 13, 2024)	€31.7 (May 01, 2025)
Negative Price Days	0	0
Negative Price Hours	55	164

1.2 Hourly Price Extremes

Metric	2024	2025
Highest Price	€950.0 (Sep 3, 2024 17:00)	€603.3 (Jan 20, 2025 16:00)
Lowest Price	€-45.0 (Apr 13, 2024 11:00)	€-100.6 (May 1, 2025 12:00)

1.3 Days by Price Range

Based on daily average prices

Range (€/MWh)	2024	2025	Δ
€0-50	23	10	-13
€51-100	181	156	-25
€101-150	110	166	+56
€151-200	32	27	-5
€201+	20	6	-14

1.4 Hours by Price Range

Based on hourly prices

Range (€/MWh)	2024	2025	Δ
Negative	55	164	+109
€0-50	1,112	950	-162
€51-100	3,990	2,683	-1,307
€101-150	2,434	3,345	+911
€151-200	613	998	+385
€201+	468	454	-14

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

164 hours with negative prices across 40 days. Most negative: €-100.6/MWh.

Intraday Price Volatility

Average daily price swing: €166/MWh. Maximum single-day swing was €489/MWh on 2025-01-20 (low: €114, high: €603).

Notable monthly evolutions

⚠️ Feb 2025: Electricity prices were 121% higher than Feb 2024

Change: +121% vs 2024

1.7 Multi-Level Price Heatmap

Price Heatmap

€/MWh

107.8 €/MWh yearly avg

hourly range: -101-603

Yearly

Monthly

Daily

Hourly

600

175

-250

2. Load

Load 2024

37.1 TWh

Load 2025

38.1 TWh

+2.6%

Production 2024

38.1 TWh

Production 2025

39.4 TWh

+3.3%

2.1 Monthly Load

Monthly Consumption vs Production

TWh per month

Consumption 2024Consumption 2025Production 2024Production 2025

2.2 Average Load by Hour of Day

4.92.50

00:0006:0012:0018:0023:00

Load Pattern

Peak demand at 10:00 (4.9 GW). Minimum at 00:00 (3.6 GW).

2.3 Weekday vs Weekend

Weekday Average

4.4 GW

Weekend Average

4.2 GW

2.4 Net Load Pattern (Duck Curve)

Net Load Pattern (excl. Solar & Wind)

GW

Solar Integration Challenge

Evening ramp of 1.5 GW from belly (09:00) to evening peak (17:00). This requires flexible dispatchable generation or storage to meet rapidly increasing demand as solar output decreases.

2.5 Seasonal Net Load Patterns

The duck curve shape varies significantly by season due to changes in solar intensity and heating/cooling demand patterns.

Winter (Dec-Feb)

Winter (Dec-Feb) Net Load Pattern

GW

Belly: 4.1 GW @ 11:00 | Peak: 5.8 GW @ 17:00 | Ramp: 1.7 GW

Spring (Mar-May)

Spring (Mar-May) Net Load Pattern

GW

Belly: 2.5 GW @ 08:00 | Peak: 4.1 GW @ 17:00 | Ramp: 1.6 GW

Summer (Jun-Aug)

Summer (Jun-Aug) Net Load Pattern

GW

Belly: 2.0 GW @ 07:00 | Peak: 3.7 GW @ 17:00 | Ramp: 1.7 GW

Fall (Sep-Nov)

Fall (Sep-Nov) Net Load Pattern

GW

Belly: 2.8 GW @ 08:00 | Peak: 4.1 GW @ 18:00 | Ramp: 1.3 GW

Seasonal Comparison

Evening ramps are similar across seasons: winter 1.7 GW, summer 1.7 GW. The grid faces consistent ramping challenges year-round.

2.6 Peak & Minimum Demand Records (2025)

Rank	Highest Load	Date	Lowest Load	Date
1	7.4 GW	2025-02-20 07:00	2.4 GW	2025-09-28 07:00
2	7.3 GW	2025-02-19 07:00	2.5 GW	2025-05-24 02:00
3	7.3 GW	2025-02-20 06:00	2.5 GW	2025-05-24 01:00

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

Key Insight

Production-based carbon intensity is 7.6g lower than flow-traced carbon intensity in 2024 (6.7g in 2025). This means Bulgaria's domestic production is slightly cleaner than consumed electricity.

Production-Based 2024

341.7 g

Production-Based 2025

358.6 g

+16.9

Flow-Traced 2024

349.4 g

Flow-Traced 2025

365.3 g

+15.9

3.1 Monthly Production Mix

Production Mix by Month

GWh per month by source

2024: left bars2025: right bars

Nuclear

Hydro

Wind

Solar

Biomass

Gas

Coal

Oil

Hydro Storage

Battery

3.2 Production Mix (Domestic Generation)

2024 Production

41%

24%

14%

9%

8%

2025 Production

39%

26%

16%

8%

8%

3.3 Flow-Traced Power Mix

2024 Flow-Traced

38%

24%

12%

11%

10%

5%

2025 Flow-Traced

36%

26%

14%

10%

9%

5%

Nuclear

Hydro

Wind

Solar

Biomass

Gas

Coal

Oil

Hydro Storage

Battery

3.5 Power Mix Comparison

Production vs Flow-Traced consumption by source

Source	Prod 2024	Flow-traced 2024	Prod 2025	Flow-traced 2025
Nuclear	41.3%	37.5%	38.9% (-2.4pp)	35.9% (-1.6pp)
Coal	24.0%	24.4%	25.8% (+1.8pp)	25.9% (+1.5pp)
Solar	13.6%	11.5%	15.9% (+2.3pp)	13.8% (+2.3pp)
Gas	9.0%	11.0%	8.2% (-0.8pp)	10.3% (-0.7pp)
Hydro	8.1%	10.0%	7.7% (-0.4pp)	9.0% (-1.0pp)
Wind	3.5%	4.9%	3.1% (-0.4pp)	4.6% (-0.3pp)
Biomass	0.4%	0.5%	0.3% (-0.1pp)	0.4% (-0.1pp)
Hydro Storage	0.0%	0.1%	0.0% (+0.0pp)	0.1% (+0.0pp)

3.6 Key Trend

Nuclear Share (Flow-Traced)

Bulgaria's electricity consumption is led by ~35.9% nuclear. Solar saw the biggest growth from 11.5% to 13.8%.

4. Cross-Border Electricity Flows

Total Exports 2025

6.08 TWh

-3.5%

Total Imports 2025

4.80 TWh

-9.8%

Net Position 2025

+1.27 TWh

Bulgaria: Net Electricity Exporter

Bulgaria exported a net 1.27 TWh in 2025.

4.1 2025 Gross Exports (Bulgaria → Neighbor)

Total electricity exported to each country — with average carbon intensity

2.37 TWh

334g

1.43 TWh

324g

0.96 TWh

328g

0.94 TWh

332g

0.37 TWh

250g

4.2 2025 Gross Imports (Neighbor → Bulgaria)

Total electricity imported from each country — with average carbon intensity

2.04 TWh

289g

1.15 TWh

446g

1.10 TWh

292g

0.32 TWh

512g

0.19 TWh

439g

4.3 Net Position by Neighbor (2025)

Neighbor	Net (TWh)	Direction
RS	+1.10	Net Exporter
MK	+0.77	Net Exporter
RO	+0.33	Net Exporter
GR	-0.15	Net Importer
TR	-0.78	Net Importer

Positive = Bulgaria is net exporter to that neighbor. Negative = Bulgaria 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 08:00 (0.8 GW avg). Peak imports at 20:00 (0.3 GW avg).

5. Carbon Intensity (gCO₂eq/kWh)

Mean 2024

349.4 g

Mean 2025

365.3 g

+15.9

Monthly Average Carbon Intensity

gCO₂eq/kWh (flow-traced)

20242025

5.1 Daily Records

Metric	2024	2025
Lowest Carbon Intensity	154.8 g (Jun 13, 2024)	191.3 g (Apr 28, 2025)
Lowest Fossil %	16.8% (Jun 12, 2024)	19.5% (Jun 16, 2025)
Highest Carbon Intensity	653.6 g (Nov 14, 2024)	598.7 g (Feb 16, 2025)
Highest Fossil %	67.0% (Nov 14, 2024)	56.5% (Dec 23, 2025)

5.2 Hourly Records

Metric	2024	2025
Lowest Carbon Intensity	107.4 g (Jun 5, 2024 07:00)	122.9 g (Jun 27, 2025 11:00)
Highest Carbon Intensity	698.3 g (Nov 18, 2024 21:00)	651.3 g (Feb 25, 2025 21:00)

5.3 Days Below Thresholds

Threshold	2024	2025	Δ
< 100 gCO₂eq/kWh	0	0	0
< 200 gCO₂eq/kWh	22	4	-18
< 300 gCO₂eq/kWh	149	156	+7

5.4 Hours Below Thresholds

Threshold	2024	2025	Δ
< 100 gCO₂eq/kWh	0	0	0
< 200 gCO₂eq/kWh	847	912	+65
< 300 gCO₂eq/kWh	3,406	3,470	+64

5.5 Average Carbon Intensity by Hour of Day

2025 Average Carbon Intensity by Hour

gCO₂eq/kWh

5.6 Seasonal Carbon Intensity Patterns

Carbon intensity daily patterns shift with seasonal changes in renewable generation and electricity demand.

Winter (Dec-Feb)

Winter (Dec-Feb) Carbon Intensity

gCO₂eq/kWh

Peak: 535 g @ 21:00 | Trough: 411 g @ 11:00 | Spread: 125 g

Spring (Mar-May)

Spring (Mar-May) Carbon Intensity

gCO₂eq/kWh

Peak: 347 g @ 21:00 | Trough: 221 g @ 09:00 | Spread: 126 g

Summer (Jun-Aug)

Summer (Jun-Aug) Carbon Intensity

gCO₂eq/kWh

Peak: 352 g @ 22:00 | Trough: 189 g @ 08:00 | Spread: 163 g

Fall (Sep-Nov)

Fall (Sep-Nov) Carbon Intensity

gCO₂eq/kWh

Peak: 408 g @ 20:00 | Trough: 275 g @ 10:00 | Spread: 133 g

Seasonal Comparison

Summer offers the lowest carbon intensity, with midday troughs reaching 189 gCO₂/kWh—54% lower than winter. Winter evening peaks are the most carbon-intensive at 535 gCO₂/kWh. Scheduling flexible loads during seasonal low-carbon windows maximizes emission reductions.

5.7 Carbon Intensity Distribution (Hourly)

Carbon Intensity Distribution

Number of hours at each level

20242025

Notable monthly evolutions

ℹ️ Jan 2025: Carbon intensity was 26% higher in Jan

Change: +26% vs Jan 2024

ℹ️ Feb 2025: Carbon intensity was 61% higher in Feb

Change: +61% vs Feb 2024

ℹ️ Apr 2025: Carbon intensity was 23% higher in Apr

Change: +23% vs Apr 2024

ℹ️ Sep 2025: Carbon intensity was 24% lower in Sep

Change: -24% vs Sep 2024

Golden Hours

1,420 hours with both low price (<€83/MWh) and low carbon intensity (<256 gCO₂eq/kWh).

5.8 Multi-Level Carbon Intensity Heatmap

Carbon Intensity Heatmap

gCO₂eq/kWh

365.3 gCO₂eq/kWh yearly avg

hourly range: 123-651

Yearly

Monthly

Daily

Hourly

1200

600

0

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

Includes electricity exchanged with neighboring grids

Renewable 2024

27.1%

Renewable 2025

27.9%

+0.8pp

Carbon-Free 2024

64.6%

Carbon-Free 2025

63.7%

-0.9pp

Monthly Carbon-Free Share

% of consumption (renewable + nuclear)

20242025

6.1 Days Above Thresholds

Days with carbon-free share above threshold

Threshold	2024	Δ
≥50% carbon-free	4	-4
≥60% carbon-free	0	0
≥70% carbon-free	0	0

6.2 Hours Above Thresholds

Hours with carbon-free share above threshold

Threshold	2024	2025	Δ
≥50% carbon-free	646	828	+182
≥60% carbon-free	146	179	+33
≥70% carbon-free	0	0	0

6.3 Multi-Level Carbon-Free % Heatmap

Carbon-Free % Heatmap

63.7 % yearly avg

hourly range: 36-89

Yearly

Monthly

Daily

Hourly

100

50

0