Electricity Grid Review 2025: Slovenia

January 1 - December 31, 2024 vs 2025

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

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

Mean 2024

€93.8

Mean 2025

€106.0

+€12.2

Monthly Average Day-Ahead Price

EUR/MWh

20242025

Price-Carbon Correlation

Correlation coefficient: -0.49 (2024), -0.49 (2025). Moderate correlation between price and carbon intensity.

1.1 Daily Price Extremes

Based on daily average prices

Metric	2024	2025
Highest Daily Avg	€353.3 (Dec 12, 2024)	€240.1 (Jan 20, 2025)
Lowest Daily Avg	€8.9 (May 01, 2024)	€25.4 (Mar 30, 2025)
Negative Price Days	0	0
Negative Price Hours	219	264

1.2 Hourly Price Extremes

Metric	2024	2025
Highest Price	€1022.3 (Aug 29, 2024 17:00)	€561.8 (Jan 20, 2025 16:00)
Lowest Price	€-105.9 (May 12, 2024 12:00)	€-126.5 (May 11, 2025 12:00)

1.3 Days by Price Range

Based on daily average prices

Range (€/MWh)	2024	2025	Δ
€0-50	30	8	-22
€51-100	198	141	-57
€101-150	114	189	+75
€151-200	17	22	+5
€201+	7	5	-2

1.4 Hours by Price Range

Based on hourly prices

Range (€/MWh)	2024	2025	Δ
Negative	219	264	+45
€0-50	1,100	669	-431
€51-100	4,256	2,831	-1,425
€101-150	2,416	3,845	+1,429
€151-200	469	794	+325
€201+	272	279	+7

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

264 hours with negative prices across 57 days. Most negative: €-126.5/MWh.

Intraday Price Volatility

Average daily price swing: €143/MWh. Maximum single-day swing was €475/MWh on 2025-06-02 (low: €11, high: €486).

Notable monthly evolutions

⚠️ Feb 2025: Electricity prices were 117% higher than Feb 2024

Change: +117% vs 2024

1.7 Multi-Level Price Heatmap

Price Heatmap

€/MWh

104.9 €/MWh yearly avg

hourly range: -127-562

Yearly

Monthly

Daily

Hourly

600

175

-250

2. Load

Load 2024

12.2 TWh

Load 2025

13.1 TWh

+6.9%

Production 2024

15.0 TWh

Production 2025

13.1 TWh

-12.5%

2.1 Monthly Load

Monthly Consumption vs Production

TWh per month

Consumption 2024Consumption 2025Production 2024Production 2025

2.2 Average Load by Hour of Day

1.70.80

00:0006:0012:0018:0023:00

Load Pattern

Peak demand at 07:00 (1.7 GW). Minimum at 01:00 (1.3 GW).

2.3 Weekday vs Weekend

Weekday Average

1.6 GW

Weekend Average

1.3 GW

2.4 Net Load Pattern (Duck Curve)

Net Load Pattern (excl. Solar & Wind)

GW

Solar Integration Challenge

Evening ramp of 0.5 GW from belly (12:00) 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)

Winter (Dec-Feb) Net Load Pattern

GW

Belly: 1.4 GW @ 02:00 | Peak: 1.8 GW @ 17:00 | Ramp: 0.4 GW

Spring (Mar-May)

Spring (Mar-May) Net Load Pattern

GW

Belly: 1.0 GW @ 12:00 | Peak: 1.5 GW @ 18:00 | Ramp: 0.6 GW

Summer (Jun-Aug)

Summer (Jun-Aug) Net Load Pattern

GW

Belly: 0.8 GW @ 12:00 | Peak: 1.4 GW @ 18:00 | Ramp: 0.6 GW

Fall (Sep-Nov)

Fall (Sep-Nov) Net Load Pattern

GW

Belly: 1.1 GW @ 01:00 | Peak: 1.6 GW @ 17:00 | Ramp: 0.5 GW

Seasonal Comparison

Evening ramps are similar across seasons: winter 0.4 GW, summer 0.6 GW. The grid faces consistent ramping challenges year-round.

2.6 Peak & Minimum Demand Records (2025)

Rank	Highest Load	Date	Lowest Load	Date
1	3.0 GW	2025-02-10 08:00	0.7 GW	2025-05-02 11:00
2	2.8 GW	2025-10-10 10:00	0.7 GW	2025-05-02 10:00
3	2.8 GW	2025-10-23 09:00	0.7 GW	2025-05-02 12:00

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

Key Insight

Production-based carbon intensity is 26.8g higher than flow-traced carbon intensity in 2024 (2.6g in 2025). This means Slovenia's imports are cleaner than domestic production, lowering the carbon footprint of consumed electricity.

Production-Based 2024

250.4 g

Production-Based 2025

196.8 g

-53.6

Flow-Traced 2024

223.6 g

Flow-Traced 2025

194.2 g

-29.4

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

36%

34%

21%

2025 Production

41%

29%

14%

7%

6%

3.3 Flow-Traced Power Mix

2024 Flow-Traced

35%

27%

17%

6%

5%

5%

2025 Flow-Traced

30%

29%

12%

9%

8%

5%

Nuclear

Hydro

Wind

Solar

Biomass

Gas

Coal

Oil

Hydro Storage

Battery

3.4 Import/Export Impact on Mix

Nuclear makes up ~41% of local production but only ~30% of consumed electricity (some exported). Slovenia produces no wind power locally, but ~5% of consumed electricity comes from wind 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	36.3%	27.3%	41.3% (+5.0pp)	29.9% (+2.6pp)
Hydro	33.5%	35.0%	28.7% (-4.8pp)	29.4% (-5.6pp)
Coal	20.7%	16.7%	13.7% (-7.0pp)	12.4% (-4.3pp)
Gas	3.2%	6.4%	7.2% (+4.0pp)	9.4% (+3.0pp)
Solar	3.5%	5.0%	5.8% (+2.3pp)	7.8% (+2.8pp)
Wind	0.0%	4.6%	0.1% (+0.1pp)	5.4% (+0.8pp)
Hydro Storage	1.8%	3.0%	2.4% (+0.6pp)	3.4% (+0.4pp)
Biomass	0.9%	2.0%	0.9% (+0.0pp)	2.3% (+0.3pp)

3.6 Key Trend

Nuclear Share (Flow-Traced)

Slovenia's electricity consumption is led by ~29.9% nuclear. Gas saw the biggest growth from 6.4% to 9.4%.

4. Cross-Border Electricity Flows

Total Exports 2025

9.06 TWh

-14.8%

Total Imports 2025

8.67 TWh

+14.7%

Net Position 2025

+0.40 TWh

Slovenia: Net Electricity Exporter

Slovenia exported a net 0.40 TWh in 2025.

4.1 2025 Gross Exports (Slovenia → Neighbor)

Total electricity exported to each country — with average carbon intensity

10.00 TWh

202g

6.71 TWh

179g

0.77 TWh

187g

0.65 TWh

223g

4.2 2025 Gross Imports (Neighbor → Slovenia)

Total electricity imported from each country — with average carbon intensity

12.05 TWh

166g

2.89 TWh

200g

2.23 TWh

248g

0.17 TWh

256g

4.3 Net Position by Neighbor (2025)

Neighbor	Net (TWh)	Direction
IT	+9.84	Net Exporter
HR	+4.48	Net Exporter
HU	-2.12	Net Importer
AT	-11.40	Net Importer

Positive = Slovenia is net exporter to that neighbor. Negative = Slovenia 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 16:00 (0.3 GW avg). Peak imports at 10:00 (0.1 GW avg).

5. Carbon Intensity (gCO₂eq/kWh)

Mean 2024

223.6 g

Mean 2025

194.2 g

-29.4

Monthly Average Carbon Intensity

gCO₂eq/kWh (flow-traced)

20242025

5.1 Daily Records

Metric	2024	2025
Lowest Carbon Intensity	32.6 g (May 10, 2024)	38.6 g (Jul 27, 2025)
Lowest Fossil %	3.0% (May 10, 2024)	4.1% (Jul 27, 2025)
Highest Carbon Intensity	402.5 g (Dec 12, 2024)	398.5 g (Oct 15, 2025)
Highest Fossil %	46.0% (Dec 12, 2024)	47.2% (Oct 15, 2025)

5.2 Hourly Records

Metric	2024	2025
Lowest Carbon Intensity	20.9 g (May 9, 2024 01:00)	29.5 g (Jun 4, 2025 21:00)
Highest Carbon Intensity	458.5 g (Nov 19, 2024 01:00)	487.1 g (Oct 15, 2025 21:00)

5.3 Days Below Thresholds

Threshold	2024	2025	Δ
< 100 gCO₂eq/kWh	29	139	+110
< 200 gCO₂eq/kWh	147	187	+40
< 300 gCO₂eq/kWh	332	306	-26

5.4 Hours Below Thresholds

Threshold	2024	2025	Δ
< 100 gCO₂eq/kWh	704	3,170	+2466
< 200 gCO₂eq/kWh	3,514	4,617	+1103
< 300 gCO₂eq/kWh	7,773	7,292	-481

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: 317 g @ 21:00 | Trough: 273 g @ 16:00 | Spread: 44 g

Spring (Mar-May)

Spring (Mar-May) Carbon Intensity

gCO₂eq/kWh

Peak: 178 g @ 02:00 | Trough: 130 g @ 12:00 | Spread: 48 g

Summer (Jun-Aug)

Summer (Jun-Aug) Carbon Intensity

gCO₂eq/kWh

Peak: 99 g @ 07:00 | Trough: 60 g @ 19:00 | Spread: 39 g

Fall (Sep-Nov)

Fall (Sep-Nov) Carbon Intensity

gCO₂eq/kWh

Peak: 229 g @ 01:00 | Trough: 187 g @ 17:00 | Spread: 42 g

Seasonal Comparison

Summer offers the lowest carbon intensity, with midday troughs reaching 60 gCO₂/kWh—78% lower than winter. Winter evening peaks are the most carbon-intensive at 317 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 Apr 2025: Carbon intensity was 27% lower in Apr

Change: -27% vs Apr 2024

ℹ️ May 2025: Carbon intensity was 28% lower in May

Change: -28% vs May 2024

ℹ️ Jun 2025: Carbon intensity was 61% lower in Jun

Change: -61% vs Jun 2024

ℹ️ Jul 2025: Carbon intensity was 56% lower in Jul

Change: -56% vs Jul 2024

ℹ️ Aug 2025: Carbon intensity was 57% lower in Aug

Change: -57% vs Aug 2024

ℹ️ Sep 2025: Carbon intensity was 45% lower in Sep

Change: -45% vs Sep 2024

ℹ️ Oct 2025: Carbon intensity was 37% higher in Oct

Change: +37% vs Oct 2024

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

Change: -24% vs Nov 2024

Golden Hours

911 hours with both low price (<€85/MWh) and low carbon intensity (<70 gCO₂eq/kWh).

5.8 Multi-Level Carbon Intensity Heatmap

Carbon Intensity Heatmap

gCO₂eq/kWh

194.2 gCO₂eq/kWh yearly avg

hourly range: 30-487

Yearly

Monthly

Daily

Hourly

1200

600

0

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

Includes electricity exchanged with neighboring grids

Renewable 2024

49.1%

Renewable 2025

47.7%

-1.4pp

Carbon-Free 2024

76.4%

Carbon-Free 2025

77.6%

+1.2pp

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	160	177	+17
≥60% carbon-free	57	67	+10
≥70% carbon-free	27	6	-21

6.2 Hours Above Thresholds

Hours with carbon-free share above threshold

Threshold	2024	2025	Δ
≥50% carbon-free	3,914	3,989	+75
≥60% carbon-free	1,616	2,085	+469
≥70% carbon-free	634	232	-402

6.3 Multi-Level Carbon-Free % Heatmap

Carbon-Free % Heatmap

77.6 % yearly avg

hourly range: 43-97

Yearly

Monthly

Daily

Hourly

100

50

0