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)
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
1.6 Price Distribution (Hourly)
164 hours with negative prices across 40 days. Most negative: €-100.6/MWh.
Average daily price swing: €166/MWh. Maximum single-day swing was €489/MWh on 2025-01-20 (low: €114, high: €603).
Notable monthly evolutions
Change: +121% vs 2024
1.7 Multi-Level Price Heatmap
Price Heatmap
€/MWh
hourly range: -101-603
Yearly
Monthly
Daily
Hourly
2. Load
2.1 Monthly Load
2.2 Average Load by Hour of Day
Peak demand at 10:00 (4.9 GW). Minimum at 00:00 (3.6 GW).
2.3 Weekday vs Weekend
2.4 Net Load Pattern (Duck Curve)
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)
Belly: 4.1 GW @ 11:00 | Peak: 5.8 GW @ 17:00 | Ramp: 1.7 GW
Spring (Mar-May)
Belly: 2.5 GW @ 08:00 | Peak: 4.1 GW @ 17:00 | Ramp: 1.6 GW
Summer (Jun-Aug)
Belly: 2.0 GW @ 07:00 | Peak: 3.7 GW @ 17:00 | Ramp: 1.7 GW
Fall (Sep-Nov)
Belly: 2.8 GW @ 08:00 | Peak: 4.1 GW @ 18:00 | Ramp: 1.3 GW
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)
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.
3.1 Monthly Production Mix
3.2 Production Mix (Domestic Generation)
3.3 Flow-Traced Power Mix
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
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
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
4.2 2025 Gross Imports (Neighbor → Bulgaria)
Total electricity imported from each country — with average carbon intensity
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
Peak exports at 08:00 (0.8 GW avg). Peak imports at 20:00 (0.3 GW avg).
5. Carbon Intensity (gCO₂eq/kWh)
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
5.6 Seasonal Carbon Intensity Patterns
Carbon intensity daily patterns shift with seasonal changes in renewable generation and electricity demand.
Winter (Dec-Feb)
Peak: 535 g @ 21:00 | Trough: 411 g @ 11:00 | Spread: 125 g
Spring (Mar-May)
Peak: 347 g @ 21:00 | Trough: 221 g @ 09:00 | Spread: 126 g
Summer (Jun-Aug)
Peak: 352 g @ 22:00 | Trough: 189 g @ 08:00 | Spread: 163 g
Fall (Sep-Nov)
Peak: 408 g @ 20:00 | Trough: 275 g @ 10:00 | Spread: 133 g
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)
Notable monthly evolutions
Change: +26% vs Jan 2024
Change: +61% vs Feb 2024
Change: +23% vs Apr 2024
Change: -24% vs Sep 2024
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
hourly range: 123-651
Yearly
Monthly
Daily
Hourly
6. Renewable & Carbon-Free Energy (Flow-Traced)
Includes electricity exchanged with neighboring grids
6.1 Days Above Thresholds
Days with carbon-free share above threshold
| Threshold | 2024 | 2025 | Δ |
|---|---|---|---|
| ≥50% carbon-free | 4 | 0 | -4 |
| ≥60% carbon-free | 0 | 0 | 0 |
| ≥70% carbon-free | 0 | 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
%
hourly range: 36-89
Yearly
Monthly
Daily
Hourly
