Electricity Grid Review 2025: Slovakia
January 1 - December 31, 2024 vs 2025
Data coverage: 366 days (2024), 365 days (2025)
1. Electricity Price (Day-Ahead, EUR/MWh)
Correlation coefficient: -0.55 (2024), -0.66 (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 | €381.4 (Dec 12, 2024) | €247.9 (Nov 25, 2025) |
| Lowest Daily Avg | €5.4 (May 01, 2024) | €25.7 (Mar 30, 2025) |
| Negative Price Days | 0 | 0 |
| Negative Price Hours | 287 | 295 |
1.2 Hourly Price Extremes
| Metric | 2024 | 2025 |
|---|---|---|
| Highest Price | €850.0 (Dec 12, 2024 16:00) | €563.1 (Jan 20, 2025 16:00) |
| Lowest Price | €-146.1 (May 12, 2024 11:00) | €-202.7 (May 11, 2025 12:00) |
1.3 Days by Price Range
Based on daily average prices
| Range (€/MWh) | 2024 | 2025 | Δ |
|---|---|---|---|
| €0-50 | 36 | 14 | -22 |
| €51-100 | 188 | 154 | -34 |
| €101-150 | 112 | 169 | +57 |
| €151-200 | 26 | 21 | -5 |
| €201+ | 4 | 7 | +3 |
1.4 Hours by Price Range
Based on hourly prices
| Range (€/MWh) | 2024 | 2025 | Δ |
|---|---|---|---|
| Negative | 287 | 295 | +8 |
| €0-50 | 1,061 | 801 | -260 |
| €51-100 | 4,192 | 3,019 | -1,173 |
| €101-150 | 2,273 | 3,417 | +1,144 |
| €151-200 | 584 | 829 | +245 |
| €201+ | 337 | 330 | -7 |
1.5 Average Price by Hour of Day
1.6 Price Distribution (Hourly)
295 hours with negative prices across 64 days. Most negative: €-202.7/MWh.
Average daily price swing: €144/MWh. Maximum single-day swing was €449/MWh on 2025-01-20 (low: €114, high: €563).
Notable monthly evolutions
Change: +122% vs 2024
1.7 Multi-Level Price Heatmap
Price Heatmap
€/MWh
hourly range: -203-563
Yearly
Monthly
Daily
Hourly
2. Load
2.1 Monthly Load
2.2 Average Load by Hour of Day
Peak demand at 17:00 (3.3 GW). Minimum at 00:00 (2.4 GW).
2.3 Weekday vs Weekend
2.4 Net Load Pattern (Duck Curve)
Evening ramp of 0.9 GW from belly (00:00) to evening peak (18:00). 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: 2.5 GW @ 00:00 | Peak: 3.5 GW @ 17:00 | Ramp: 1.0 GW
Spring (Mar-May)
Belly: 2.3 GW @ 01:00 | Peak: 3.1 GW @ 18:00 | Ramp: 0.8 GW
Summer (Jun-Aug)
Belly: 2.1 GW @ 01:00 | Peak: 2.9 GW @ 18:00 | Ramp: 0.9 GW
Fall (Sep-Nov)
Belly: 2.3 GW @ 01:00 | Peak: 3.3 GW @ 17:00 | Ramp: 1.0 GW
Evening ramps are similar across seasons: winter 1.0 GW, summer 0.9 GW. The grid faces consistent ramping challenges year-round.
2.6 Peak & Minimum Demand Records (2025)
| Rank | Highest Load | Date | Lowest Load | Date |
|---|---|---|---|---|
| 1 | 5.7 GW | 2025-08-07 07:00 | 0.9 GW | 2025-04-15 03:00 |
| 2 | 5.7 GW | 2025-08-07 15:00 | 1.0 GW | 2025-04-15 02:00 |
| 3 | 5.6 GW | 2025-08-07 09:00 | 1.0 GW | 2025-04-15 01:00 |
3. Production-Based vs Flow-Traced Carbon Intensity (gCO₂eq/kWh)
Production-based carbon intensity is 107.3g lower than flow-traced carbon intensity in 2024 (121.6g in 2025). This means Slovakia'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
3.4 Import/Export Impact on Mix
Nuclear makes up ~71% of local production but only ~55% of consumed electricity (some exported). Slovakia produces no wind power locally, but ~3% of consumed electricity comes from wind imports. Slovakia produces no coal power locally, but ~14% of consumed electricity comes from coal imports.
3.5 Power Mix Comparison
Production vs Flow-Traced consumption by source
| Source | Prod 2024 | Flow-traced 2024 | Prod 2025 | Flow-traced 2025 |
|---|---|---|---|---|
| Nuclear | 66.2% | 53.3% | 71.1% (+4.9pp) | 54.8% (+1.5pp) |
| Coal | 0.9% | 13.4% | 0.2% (-0.7pp) | 14.2% (+0.8pp) |
| Gas | 8.9% | 8.1% | 10.5% (+1.6pp) | 9.5% (+1.4pp) |
| Hydro | 17.2% | 12.8% | 11.2% (-6.0pp) | 8.0% (-4.8pp) |
| Solar | 2.0% | 3.9% | 2.1% (+0.1pp) | 4.4% (+0.5pp) |
| Wind | 0.0% | 2.9% | 0.0% (+0.0pp) | 3.2% (+0.3pp) |
| Biomass | 3.2% | 3.1% | 3.2% (+0.0pp) | 2.9% (-0.2pp) |
| Hydro Storage | 0.3% | 1.6% | 0.2% (-0.1pp) | 1.9% (+0.3pp) |
| Oil | 1.3% | 1.0% | 1.5% (+0.2pp) | 1.1% (+0.1pp) |
3.6 Key Trend
Slovakia's electricity consumption is dominated by ~54.8% nuclear. Nuclear saw the biggest growth from 53.3% to 54.8%.
4. Cross-Border Electricity Flows
Slovakia exported a net 2.55 TWh in 2025.
4.1 2025 Gross Exports (Slovakia → Neighbor)
Total electricity exported to each country — with average carbon intensity
4.2 2025 Gross Imports (Neighbor → Slovakia)
Total electricity imported from each country — with average carbon intensity
4.3 Net Position by Neighbor (2025)
| Neighbor | Net (TWh) | Direction |
|---|---|---|
| HU | +14.47 | Net Exporter |
| UA | +2.69 | Net Exporter |
| PL | -4.67 | Net Importer |
| CZ | -9.92 | Net Importer |
Positive = Slovakia is net exporter to that neighbor. Negative = Slovakia is net importer from that neighbor.
4.4 Flow Pattern by Hour of Day
Peak exports at 17:00 (0.6 GW avg). Peak imports at 10:00 (0.2 GW avg).
5. Carbon Intensity (gCO₂eq/kWh)
5.1 Daily Records
| Metric | 2024 | 2025 |
|---|---|---|
| Lowest Carbon Intensity | 92.5 g (Mar 31, 2024) | 124.4 g (May 31, 2025) |
| Lowest Fossil % | 11.0% (Mar 31, 2024) | 14.4% (Sep 07, 2025) |
| Highest Carbon Intensity | 393.3 g (Nov 15, 2024) | 348.8 g (Jan 21, 2025) |
| Highest Fossil % | 47.3% (Nov 14, 2024) | 43.0% (Jan 21, 2025) |
5.2 Hourly Records
| Metric | 2024 | 2025 |
|---|---|---|
| Lowest Carbon Intensity | 72.5 g (Sep 29, 2024 14:00) | 76.4 g (Jul 9, 2025 08:00) |
| Highest Carbon Intensity | 431.8 g (Nov 15, 2024 04:00) | 390.6 g (Jul 16, 2025 22:00) |
5.3 Days Below Thresholds
| Threshold | 2024 | 2025 | Δ |
|---|---|---|---|
| < 100 gCO₂eq/kWh | 1 | 0 | -1 |
| < 200 gCO₂eq/kWh | 160 | 140 | -20 |
| < 300 gCO₂eq/kWh | 337 | 327 | -10 |
5.4 Hours Below Thresholds
| Threshold | 2024 | 2025 | Δ |
|---|---|---|---|
| < 100 gCO₂eq/kWh | 244 | 96 | -148 |
| < 200 gCO₂eq/kWh | 3,844 | 3,196 | -648 |
| < 300 gCO₂eq/kWh | 7,742 | 7,253 | -489 |
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: 318 g @ 21:00 | Trough: 247 g @ 11:00 | Spread: 71 g
Spring (Mar-May)
Peak: 261 g @ 21:00 | Trough: 164 g @ 09:00 | Spread: 97 g
Summer (Jun-Aug)
Peak: 239 g @ 22:00 | Trough: 131 g @ 08:00 | Spread: 107 g
Fall (Sep-Nov)
Peak: 257 g @ 20:00 | Trough: 179 g @ 10:00 | Spread: 77 g
Summer offers the lowest carbon intensity, with midday troughs reaching 131 gCO₂/kWh—47% lower than winter. Winter evening peaks are the most carbon-intensive at 318 gCO₂/kWh. Scheduling flexible loads during seasonal low-carbon windows maximizes emission reductions.
5.7 Carbon Intensity Distribution (Hourly)
Notable monthly evolutions
Change: +43% vs Jan 2024
Change: +61% vs Feb 2024
Change: +28% vs Mar 2024
Change: +43% vs Apr 2024
Change: -22% vs Jun 2024
Change: -29% vs Aug 2024
1,242 hours with both low price (<€82/MWh) and low carbon intensity (<175 gCO₂eq/kWh).
5.8 Multi-Level Carbon Intensity Heatmap
Carbon Intensity Heatmap
gCO₂eq/kWh
hourly range: 76-391
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 | 0 | 0 | 0 |
| ≥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 | 0 | 0 | 0 |
| ≥60% carbon-free | 0 | 0 | 0 |
| ≥70% carbon-free | 0 | 0 | 0 |
6.3 Multi-Level Carbon-Free % Heatmap
Carbon-Free % Heatmap
%
hourly range: 52-91
Yearly
Monthly
Daily
Hourly
