Best Solar Forecast App UK: The Simplest, Compared
We make one of these, so we’ll be upfront. But “best” depends on how much setup you’ll actually tolerate. Here’s an honest comparison of the main UK solar forecast tools — by how many details they need before they tell you anything useful, and who each one really suits.
| Tool | What it needs to start | Setup |
|---|---|---|
| Sun Hours | Postcode + your best-ever daily kWh | 2 inputs, no account |
| Solcast (home tools) | Location + tilt + azimuth + capacity (kW) | 4+ inputs |
| Forecast.Solar | Lat/lon + declination + azimuth + kWp | API parameters |
| Inverter apps (SolarmanPV, S-Miles) | Own the inverter + create a login | Account + pairing |
| PVOutput | System profile + data feed | Technical setup |
Sun Hours
Best for: A quick daily 'is today worth it?' check for plug-in, balcony and rooftop owners. Not for you if: you want array-level engineering detail or an api.
Solcast (home tools)
Best for: Fixed rooftop arrays where you want precise, array-modelled output. Not for you if: you just want a two-second glance without configuring your array.
Forecast.Solar
Best for: Home Assistant, DIY and automation setups pulling a forecast into dashboards. Not for you if: you want a friendly consumer app, not an api.
Inverter apps (SolarmanPV, S-Miles)
Best for: Seeing your real measured generation once the system is installed. Not for you if: you want a forecast before buying, or your kit has no cloud app.
PVOutput
Best for: Community logging and deep historical analysis. Not for you if: you want simple and quick.
Try the simplest one
Postcode, your best-ever day, done — Sol gives you a personalised 7-day forecast in under a minute. Free, no account.
FAQ
What is the simplest solar forecast app in the UK?
Sun Hours — two inputs (postcode + your best-ever daily kWh), no account, no inverter login. Solcast and Forecast.Solar are more precise but need your array's tilt, azimuth and capacity.
Best solar forecast app for plug-in solar owners?
Sun Hours fits plug-in and balcony solar best because there's no inverter integration — you calibrate with your best day and get a 7-day forecast. Solcast suits fixed rooftop; Forecast.Solar suits automation via API.
Is Sun Hours a good Solcast alternative?
For a quick daily check, yes — far less setup. Solcast wins for array-level precision or an API. Plenty of owners use both: Sun Hours for the daily glance, Solcast for the detail.
Related: plug-in solar UK · balcony solar UK · live GB solar