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Check out the key developments from September 2025 below.
Executive Summary
In September 2025, Europe’s power system remained stable as seasonal shifts reshaped the generation mix and cross-border dynamics. Overall electricity demand edged up slightly from August (+0.4%) but stayed nearly flat year-on-year (−0.4%), marking a return to typical post-summer activity following the August slowdown.
Renewables accounted for 49.15% of total EU generation, broadly unchanged from August. Wind output rose +35.6% month-on-month, offsetting a −24.7% decline in solar generation due to reduced daylight hours. However, solar’s performance remained impressive in September with Solar PV electricity overtaking Natural gas first time in any September becoming third largest source of electricity. Germany and the Netherlands recorded the strongest wind gains, while Portugal and Denmark maintained renewable shares above 85%. In France, rising nuclear (+1.9% MoM) and renewable generation (+8.7% MoM) reinforced an already low-carbon supply mix, allowing further reductions in fossil output (−55% MoM).
The EU’s average CO₂ intensity declined to 151.8 gCO₂/kWh (−1.3% MoM; −7.1% YoY), continuing its downward trend. France’s flexible nuclear operations and Greece’s and Hungary’s solar-driven gains contributed to cleaner generation profiles across several regions.
Day-ahead electricity prices averaged €81.2/MWh, up from August but still below last year’s level. Regional price spreads narrowed compared with 2024, though notable contrasts persisted between western and southern markets. France recorded one of Europe’s lowest averages at €34.8/MWh, with sharp dips during mid-September linked to cross-border congestion that temporarily constrained exports. Italy remained among the highest-priced markets (~€110/MWh), while Spain, Portugal, and the Nordic zones traded between €35–62/MWh.
France also retained its position as Europe’s largest net exporter (+8.75 TWh), followed by Sweden (+2.11 TWh) and Norway (+1.66 TWh). Italy (−3.88 TWh) and Germany (−1.61 TWh) remained the leading importers, while the Netherlands recorded lower exports compared with August.
Electricity generation
Renewables accounted for 49.2 % of EU electricity generation in September, remaining broadly stable from August (−0.22 pp MoM; +0.98 pp YoY). Solar output declined by 24.7% month-on-month, while wind generation increased by 35.6%, largely compensating for the expected seasonal reduction in sunlight hours. However, solar’s performance remained impressive in September with Solar PV electricity overtaking Natural gas first time in any September becoming third largest source of electricity.
Germany (+69%) and the Netherlands (+77%) recorded the strongest month-on-month increases in wind generation, reflecting stronger North Sea winds and favourable weather conditions. This recovery helped offset weaker solar production across southern Europe. Portugal and Denmark maintained renewable shares around 85% or higher, sustaining consistent clean generation despite the seasonal transition.
In France, nuclear generation increased by 1.9% MoM while gas-fired generation fell by 55%, reinforcing an already low-emission supply structure. Renewable output rose by 8.7%, supported by higher wind generation and stable hydro performance.
Finland posted a 12% rise in renewable generation driven by improved wind and hydro conditions, while Spain recorded a moderate 6.4% month-on-month decline after strong summer output. Across the EU, fossil generation decreased by 1% month-on-month and 3.7% year-on-year, while renewables grew modestly on both measures.
For the third September in a row since 2023, renewables have outperformed fossil fuels in Europe’s energy mix. This shows that the continent’s power system is not merely responding to seasonal variability but steadily cutting its reliance on fossil generation through sustained renewable growth and a stable low-carbon base.
Electricity demand
EU electricity demand totalled 207.84 TWh in September, up 0.43% month-on-month but 0.37% lower year-on-year. The modest rebound followed August’s holiday-related slowdown, as activity levels returned closer to seasonal norms. Cooler early-autumn temperatures and reduced heat stress lowered residential cooling demand, keeping overall consumption broadly steady despite the slight increase in working-day activity.
Germany (+2.3%), France (+2.1%), and Italy (+6.2%) all recorded higher demand compared to August, while Greece (−24.8%) and Croatia (−13.0%) saw the sharpest declines as tourism-related consumption tapered off. Finland (−3.4%) and Sweden (−0.2%) registered small decreases amid mild Nordic weather.
Spain posted a 7.0% month-on-month decline but remained 6.8% above September 2024, while Poland (+7.6%) recorded the strongest monthly gain among major economies.
At the EU level, demand patterns largely returned to typical post-summer conditions — modest increases in central and northern markets and seasonal softening in the south.
CO2eq intensity
The EU’s average CO₂ intensity declined to 151.8 gCO₂/kWh in September (−1.3% MoM; −7.1% YoY), continuing the gradual downward trend observed through the summer. Lower fossil output, supported by stronger wind conditions and steady nuclear generation, helped offset weaker hydropower performance in parts of Central Europe.
At the national level, France made a visible contribution to the EU-wide decline. With nuclear generation up by more than 6% YoY and flexible operations introduced since late summer, France maintained an exceptionally low CO₂ intensity of around 5 g/kWh, one of the lowest in Europe. Greece (−22% YoY) and Hungary (−36% YoY) also showed clear improvements driven by solar generation, while Austria and Belgium recorded temporary increases in intensity due to lower hydropower output.
After a sharp decline through the first half of the year, EU carbon intensity has remained low and broadly stable since summer.
Day-ahead electricity prices
EU day-ahead prices averaged €77.02/MWh in August, down -€3.27 from July and -€13.89 YoY. The decline reflects weaker demand, lower gas prices, and higher renewable penetration compared with last year. Natural gas benchmarks (TTF) remained around €31–32/MWh, well below earlier peaks, easing cost pressures on power markets.
The frequency of price spikes (≥€150/MWh) fell YoY, showing that short-term volatility persists even in a generally softer market. The frequency of negative prices declined YoY, in line with reduced oversupply.
National patterns diverged:
- Italy again recorded no negative hours and one of the highest averages (~€109/MWh).
- France averaged ~€54/MWh with frequent negative hours.
- Spain and Portugal stayed in the high-€60s, supported by solar output.
- Nordic zones maintained the lowest averages, increased hydro production and frequent negative prices.
Cross-border flows
France remained Europe’s largest net exporter in September (+8.75 TWh), supported by strong nuclear generation. Despite temporary transmission congestion in mid-September, French exports increased +12.4% year-on-year, maintaining the country’s dominant position in regional power flows.
Sweden was the second-largest exporter (+2.11 TWh), while Norway continued to supply power to EU markets with +1.66 TWh of net exports. On the import side, Italy (−3.88 TWh) and Germany (−1.61 TWh) remained the region’s largest net importers, while the Netherlands recorded lower exports compared with August.
Check all the data here or contact Mohammed Abi Afthab Olikathodi (aolikathodi@eurelectric.org)
This blog post was originally published as part of Eurelectric’s AskElda Monthly newsletter on LinkedIn. Subscribe here to stay updated and never miss an edition.
Disclaimer: The latest estimates for electricity generation, demand and CO2 intensity are provided by Eurelectric, based on the most recent hourly data from ENTSO-E and monthly data from Eurostat of the previous year. These figures are subject to slight revisions as actual data becomes available. The aggregate statistics mentioned here refer to the EU-27.