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Solar forecast for tomorrow
See how much energy your panels could produce, in kWh, and when to use it. Enter your location and PV size for a free forecast — no account or inverter connection needed.
Enter a location and PV size to begin.
Tomorrow's solar signal
ForecastLikely rangeClear sky (no clouds)NightBest use window
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Regional forecast near you
Tomorrow
- Likely daily range
- Best use window (local time)
Approximate location from your IP address. A city reference, not a forecast for your roof.
Enter a location and PV size to see the forecast.
Weather input
Sun, clouds and rain by hour.
Brighter sun means stronger irradiance. Darker cloud means more cover. Blue marks rain risk.
Total sun-sun hitting the roof
Direct sun-strongest clear beam
Scattered light-light through cloud
Clouds-day avg
Only real production can teach the model your roof.
GridPassport turns that into more accurate forecasts and battery, inverter and load control.
Tomorrow, in one email
Tomorrow's solar, ready in your inbox.
Expected kWh, likely range and the best four-hour solar window for the PV setup above. Sent daily.
Forecast quality
No forecast loaded yet.
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Turn a PV forecast into a plan for your home.
Start with tomorrow, then check the hourly outlook. Production is not the same as surplus: subtract household demand before planning a battery charge, EV session or hot-water cycle.
- Expected production
- The median modelled energy in kWh for the selected day — not grid export or instantaneous power.
- Likely range
- A lower-to-upper modelled range. Changing clouds and site-specific conditions can still put real output outside it.
- Best use window
- The hours with the strongest expected output. Check your live surplus before switching on large loads.
- Clear-sky reference
- A comparison with production under clear-sky conditions.
Solar by place
Forecasts for 381 European cities
PolandGermanyNetherlandsCzechiaSlovakiaUnited KingdomIrelandSpainFranceItalyDenmarkAustriaBelgium+29
Compare dated forecasts and long-term monthly PVGIS profiles using the same 10 kWp reference system in 42 countries. For your own roof, adjust the calculator above.
Make the forecast useful
Plan solar around your battery, car and home
Practical examples with clear assumptions — not promises of savings or guaranteed production.
Battery planning
How much should you charge overnight?
Work through battery reserve, expected demand and the space to leave for tomorrow’s solar.
EV charging
Use solar without missing your departure target
Separate the daily energy budget from charger power and the hours when the car is at home.
Heat pump & hot water
Move flexible heating into the solar window
Plan around comfort, equipment limits and the heat your home actually needs.
Check your result
Forecast versus inverter: what to compare
Check dates, roof inputs and production readings before judging the forecast error.
Seasonal production
What does a 5 kWp system produce in winter?
Compare monthly PVGIS profiles for Berlin, London, Warsaw and Madrid, with explicit assumptions.
Matching solar to a tariff? Compare household electricity price benchmarks or learn how time-of-use and dynamic tariffs differ.
Solar production forecast: common questions
How much solar energy will my panels produce tomorrow?
Enter your location and installed panel capacity in kWp, then choose Show forecast. You will see a dated estimate in kWh, a likely range and the strongest solar hours. Add your roof direction, tilt, shading and inverter limit in Advanced setup to make the assumptions closer to your installation. This is a modelled estimate, not a production guarantee.
Can I check today as well as tomorrow?
Yes. Tomorrow is the default view. After generating a forecast, switch to Today + tomorrow or the 72-hour outlook. These are weather-based production estimates, not readings from your inverter or a measurement of how much energy is left today.
Is this solar forecast free, and do I need an account?
The public calculator is free to use without an account or connecting your inverter. Start with a location and panel capacity. Your browser can remember your setup; use Clear saved setup to remove it.
What is the difference between kW, kWp and kWh?
kWp is the rated capacity of your panels under standard test conditions. kW is power at a particular moment. kWh is energy over a period: 2 kW sustained for 3 hours produces 6 kWh. Enter panel capacity in kWp; the daily forecast is in kWh.
Is tomorrow’s forecast the same as a PVGIS monthly average?
No. The forecast uses dated weather for the selected location. PVGIS monthly and annual profiles describe long-term climate-based production under reference assumptions. They are useful for seasonal comparisons, but a monthly average cannot tell you whether tomorrow will be cloudy.
Why can the forecast differ from my inverter reading?
Weather can change, and a model cannot fully represent local shade, snow, dirt, clipping or every roof layout. Compare PV generation, not grid export, over the same local date and with the same forecast version. The likely range shows uncertainty; it is not a guarantee that every real installation will fall inside it.
For sources, assumptions and limitations, read the forecast methodology. For a measured example, see our forecast accuracy case study.