Dated, weather-based
Tomorrow's forecast
Tomorrow's value is a weather-based estimate for Tuesday, September 1, 2026: 34.7 kWh from the 10 kWp reference system, with a likely range of 24.5 kWh–44.8 kWh. It changes with the next weather forecast.
Romania · 10 kWp reference system
Cluj-Napoca solar forecast and PV yield
Photo: Dennis G. Jarvis,CC BY-SA 2.0. Cropped, resized and converted to WebP by GridPassport.
Forecast target: . Any “tomorrow” label on this page refers to this dated target.
- Tomorrow's forecast
- 34.7 kWh 10 kWp reference system
- Typical annual output
- 12,156 kWh 10 kWp reference system
- Typical specific yield
- 1,216 kWh/kWp Per year
Tuesday, September 1, 2026
About 34.7 kWh tomorrow
For a standard 10 kWp south-facing system in Cluj-Napoca, GridPassport estimates 34.7 kWh on Tuesday, September 1, 2026, with a likely range of 24.5-44.8 kWh. The strongest production window is expected at 14:00-18:00 local time.
Updated Aug 31, 2026, 02:01 AM GMT+3 · fresh snapshot- Likely range
- 24.5-44.8 kWh
- Strongest window
- 14:00-18:00
- Confidence
- medium
How to read and use the data
Cluj-Napoca solar forecast: daily weather versus long-term PV yield
The daily and annual figures answer different questions. Use the dated forecast to plan tomorrow, and the PVGIS specific yield to compare locations or estimate a typical year.
Multi-year climate baseline
PVGIS specific yield
Cluj-Napoca's PVGIS specific yield is about 1,216 kWh/kWp per year. It is a multi-year climate benchmark, not a prediction for tomorrow or for this calendar year. In the PVGIS profile, July is typically the strongest month and December the weakest.
3, 5 and 10 kWp reference systems
Scale the same assumptions to your system size
SystemTomorrow estimate (likely range)PVGIS typical year
3 kWpTomorrow estimate (likely range)10.4 kWh7.3 kWh–13.4 kWhPVGIS typical year3,647 kWh/year
5 kWpTomorrow estimate (likely range)17.4 kWh12.3 kWh–22.4 kWhPVGIS typical year6,078 kWh/year
10 kWpTomorrow estimate (likely range)34.7 kWh24.5 kWh–44.8 kWhPVGIS typical year12,156 kWh/year
Linear reference scaling only: south-facing, 35° tilt and 14% system losses. It does not resize inverter clipping, shade or local roof constraints.
From forecast to a household plan
Battery, EV, heat pump and flexible loads
Treat the forecast as a gross solar-energy budget before household base load and conversion losses. The numbers support scheduling; they do not guarantee surplus.
Battery
Keep room for the solar window
Use 14:00-18:00 as the first candidate charging window. Battery state of charge, reserve settings and inverter limits still decide how much can be stored.
EV
Compare the charge with the 5 kWp budget
The scaled 5 kWp estimate is 17.4 kWh before household use. Compare the remainder after base load with the planned EV charge and stagger charging if needed.
Heat pump
Shift only flexible thermal demand
If comfort controls allow it, place discretionary hot-water heating or pre-heating inside 14:00-18:00. Never override frost protection, hygiene cycles or manufacturer limits.
Large loads
Avoid stacking appliances
A 3 kWp system scales to about 10.4 kWh for the day before household use. Run flexible loads sequentially during the strongest hours rather than assuming all forecast energy is simultaneous power.
Local questions
Solar forecast FAQ
How much could a 5 kWp solar system produce tomorrow in Cluj-Napoca?
Using the same south-facing, 35-degree and 14% loss assumptions, the 5 kWp estimate is 17.4 kWh for Tuesday, September 1, 2026, with a scaled likely range of 12.3 kWh–22.4 kWh. This is a linear reference-system estimate, not a site survey.
What does 1,216 kWh/kWp mean for Cluj-Napoca?
It means the PVGIS multi-year profile produces about 1,216 kWh in a typical year for each installed kWp under the reference assumptions. A 5 kWp system therefore scales to about 6,078 kWh in a typical year before site-specific adjustments.
Is the Cluj-Napoca forecast the same as the PVGIS annual estimate?
No. Tomorrow's forecast uses dated weather and an uncertainty band for one day. The PVGIS figure is a multi-year climate-based specific yield used for typical monthly and annual comparisons.
When should a battery, EV or heat pump use solar in Cluj-Napoca?
Start with 14:00-18:00, then check household base load, battery headroom, EV energy required and heat-pump safety or comfort constraints. The forecast estimates daily energy, not guaranteed instantaneous surplus.
Typical year
Solar production month by month in Cluj-Napoca
A standard 10 kWp system produces about 12,156 kWh in a typical year at this location. Monthly averages show seasonality; they are not a forecast for a specific year.
496Jan
680Feb
1070Mar
1204Apr
1306May
1348Jun
1419Jul
1394Aug
1183Sep
1008Oct
630Nov
418Dec
Values are kWh per month. Source: European Commission JRC PVGIS.
What makes Cluj-Napoca's solar profile different?The typical annual yield is about 1,216 kWh per installed kWp, ranking Cluj-Napoca #4 of 6 modelled locations in Romania. That is 2% below the median of the 6 Romania locations in this dataset. July is typically the strongest month and December the weakest; the stronger month produces about 3.4 times as much.
See the 12-month data
MonthMonthly outputDaily averageYear-to-year variation
MonthJanuaryMonthly output496 kWhDaily average16.0 kWh/dayYear-to-year variation±93 kWh
MonthFebruaryMonthly output680 kWhDaily average24.3 kWh/dayYear-to-year variation±121 kWh
MonthMarchMonthly output1,070 kWhDaily average34.5 kWh/dayYear-to-year variation±209 kWh
MonthAprilMonthly output1,204 kWhDaily average40.1 kWh/dayYear-to-year variation±171 kWh
MonthMayMonthly output1,306 kWhDaily average42.1 kWh/dayYear-to-year variation±141 kWh
MonthJuneMonthly output1,348 kWhDaily average44.9 kWh/dayYear-to-year variation±125 kWh
MonthJulyMonthly output1,419 kWhDaily average45.8 kWh/dayYear-to-year variation±110 kWh
MonthAugustMonthly output1,394 kWhDaily average45.0 kWh/dayYear-to-year variation±122 kWh
MonthSeptemberMonthly output1,183 kWhDaily average39.4 kWh/dayYear-to-year variation±157 kWh
MonthOctoberMonthly output1,008 kWhDaily average32.5 kWh/dayYear-to-year variation±157 kWh
MonthNovemberMonthly output630 kWhDaily average21.0 kWh/dayYear-to-year variation±125 kWh
MonthDecemberMonthly output418 kWhDaily average13.5 kWh/dayYear-to-year variation±98 kWh
Nearby solar forecasts
Compare Cluj-Napoca with nearby cities
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Tomorrow, in one email
Get Cluj-Napoca's solar forecast by email
Tomorrow's expected production, likely range and strongest hours. One useful email each day.
Method and data
Every city uses a 10 kWp system facing south at 35 degrees with 14% system losses. Tomorrow's figure combines hourly weather with GridPassport's PV production and uncertainty model. The monthly profile uses the European Commission JRC PVGIS multi-year climate series. Roof direction, shade, snow, dirt, inverter clipping and local weather can change real output.
CSV and JSON snapshots are published under CC BY 4.0 with source attribution.