IN Brief:
- Slovenia recorded 996GWh of net electricity generation in July, down 9% year on year and 13% from June.
- Hydropower fell 35% annually and thermal generation 41%, while estimated solar and wind output increased 30%.
- Imports reached 1,035GWh against 897GWh of exports, with manufacturing consuming 307GWh during the month.
The Statistical Office of the Republic of Slovenia recorded 996GWh of net electricity generation in July, 9% below the same month of 2025 and 13% lower than in June.
The decline was concentrated in hydroelectric and conventional thermal production. Hydropower generated 212GWh, down 35% year on year and 44% from June, while conventional thermal plants produced 47GWh, 41% below July 2025 but 4% above the previous month.
Nuclear production was considerably steadier at 497GWh, unchanged on a rounded percentage basis from June and 2% below a year earlier. Estimated solar and wind generation moved in the opposite direction, reaching 240GWh, 30% above July 2025 and 3% above June.
Cross-border flows compensated for part of the weaker domestic production. Slovenia imported 1,035GWh during July and exported 897GWh, compared with imports of 1,025GWh and exports of 1,051GWh a year earlier.
The volume available for the internal market reached 1,095GWh, 6% higher year on year and 1% above June. Households consumed 234GWh and business users 618GWh, with manufacturing accounting for 307GWh of business consumption.
Hydro variability changes the monthly balance
The July figures show how significantly hydropower can alter Slovenia’s generation balance from one month to the next. Output from hydro stations fell from 377GWh in June to 212GWh in July, removing 165GWh of domestic production within a single month.
The increase from solar and wind was much smaller in absolute terms. Their combined estimated production rose by 6GWh from June, while nuclear output increased by 2GWh and conventional thermal production by 2GWh.
That leaves imports and changes in other system flows carrying more of the adjustment. Cross-border electricity movements are routine within the interconnected Continental European system, and the fact that imports exceeded domestic net generation does not mean imported electricity alone supplied a corresponding share of Slovenian consumption.
Electricity can enter and leave the country according to regional prices, available transmission capacity, scheduled exchanges, generation conditions, and wider European market flows. Monthly import and export totals therefore describe physical and commercial transfers rather than a simple measure of national dependency.
They do show that interconnection provides an important source of flexibility when domestic production changes. Lower hydro output can be compensated through other generation, storage, altered demand, or cross-border transfers, depending on what is available and economic during each operating interval.
Hydro and solar also contribute different system characteristics despite both being renewable. Reservoir-based hydro can offer controllable output where water availability and operating rules permit, while photovoltaic generation is concentrated around daylight and follows irradiance.
Replacing one megawatt-hour of hydro with one megawatt-hour of solar across a monthly energy total therefore does not produce an identical power-system profile. The timing of output, ramping capability, reserve contribution, and ability to respond to dispatch all differ.
Nuclear generation provided the most stable large block in the July figures. At 497GWh, it represented roughly half of Slovenia’s domestic net production during the month and changed little compared with June.
That steadier output helped limit the effect of the hydro reduction, but large nuclear units carry their own operational characteristics. Planned maintenance or an unplanned outage can remove a substantial block of generation at once, requiring sufficient reserve and cross-border capability elsewhere on the system.
Solar and wind production reached 240GWh, compared with 185GWh a year earlier. The 30% annual increase shows how variable renewables are becoming a larger element of the Slovenian generation mix, although the Statistical Office notes that this combined figure is estimated.
Greater variable generation increases the value of resources capable of responding over different timescales. Hydropower, storage, flexible thermal generation, demand response, and interconnection can all help reconcile short-term differences between renewable production and consumption.
Monthly statistics cannot show those balancing requirements directly. A system can record equal generation and consumption over a month while still experiencing large hourly surpluses and deficits, which is why network operation depends on shorter-duration data and reserve procurement as well as aggregate energy totals.
The demand figures also retain a strong industrial component. Manufacturing used 307GWh in July, almost half of the 618GWh consumed by business entities and more electricity than the entire household sector.
That industrial load means generation and network conditions feed directly into the operating environment for Slovenian factories. Transmission capacity, interconnection, generation availability, and wholesale market conditions all influence how reliably and economically that demand can be supplied.
SURS classifies the most recent three months of data as provisional, allowing later revisions as additional information is received. The current figures should therefore be treated as the July operating picture rather than a final annual statistical series.
For July, that picture is unusually clear: hydro output fell sharply, nuclear generation remained comparatively stable, solar and wind increased, and Slovenia drew more electricity through its cross-border connections while business and household demand both rose from June.
Source: SURS
