Help & Support
Get help configuring OnSun, understanding your solar forecast, and making the most of every ray of sunlight.
Get help configuring OnSun, understanding your solar forecast, and making the most of every ray of sunlight.
OnSun helps households forecast solar generation and run appliances at peak solar times to reduce grid imports. It provides weather-based forecasts, projected savings estimates, and scheduling suggestions to help you make the most of your solar system.
Note: OnSun does not control appliances automatically. You remain in control of when and how you operate your equipment.
We're constantly working to make OnSun better. If the forecasting isn't quite right for your location, if the scheduling logic could be refined, or if you have ideas for new features — we'd love to hear from you.
Your feedback directly shapes the app. Please don't hesitate to reach out.
Email usOnSun uses weather data and solar forecasting algorithms to estimate your solar generation throughout the day. Forecasts consider factors like cloud cover, time of year, and your location. Because solar generation depends on many uncontrollable factors — weather, shading, and system performance — forecasts are estimates and real-world results may differ.
In most regions, forecasts are provided in hourly intervals. In areas with higher-resolution meteorological coverage, the models produce 15-minute interval forecasts. Your location determines the time resolution you see in the app. OnSun automatically uses the highest resolution available for your region.
Savings estimates are based on your forecasted solar generation and typical energy rates. The app compares running appliances during peak solar times versus importing from the grid. These are projections only; actual savings will depend on your specific energy plan, usage patterns, and real-world solar output.
OnSun offers free and paid subscription tiers. Subscriptions are managed through your device's app store (Apple App Store or Google Play). This means:
Open OnSun, go to Settings, and tap "Restore Purchases." Ensure you're signed in with the same Apple ID (iOS) or Google account (Android) used for the original purchase.
OnSun uses simplified appliance load profiles to make scheduling straightforward. Real-world appliances often have variable power draw — heating elements cycle, motors ramp up, and rinse cycles differ from wash cycles. Our scheduler treats the total energy needed as a flexible block within your solar window, which works well for most households.
If you need detailed block-profile scheduling (for example, to avoid peak tariff periods or coordinate with home battery cycling), please get in touch. This feature is supported by our architecture and community interest helps us prioritise it.
For the most accurate forecasts, take a few minutes to configure your system settings. Here's what each setting means and how to find the right values.
The total capacity of your solar panels in kilowatts (kW). Shown on your solar quote, inverter display, or monitoring app.
Typical range: 3.0 to 10.0 kW
Common sizes: 6.6 kW (very popular), 5.0 kW, 10 kW for larger homes.
The angle your panels are tilted from horizontal. Flat roof = 0°, vertical wall = 90°.
Quick guide:
Your installer's documentation or your phone's level app can give you this.
The compass direction your panels face. 0° = North, 180° = South.
Common directions:
Use your phone's compass while standing in front of your panels.
A factor accounting for real-world losses: shading, dust, inverter efficiency, temperature, and wiring losses. Think of it as overall system efficiency.
Typical values:
Most users can leave this at 0.85. Lower it if you have significant shading or an older system.
Your home's minimum power consumption (in kW) when no major appliances are running — fridges, standby devices, routers, etc.
How to estimate:
This helps OnSun calculate how much solar is available for your appliances.
The maximum AC output your inverter can deliver. Only needed if your inverter is significantly smaller than your panel capacity.
Example: 8 kW of panels with a 5 kW inverter would have a limit of 5.0 kW.
If your inverter and panel sizes are similar, leave this blank.
Your home's location determines sun angles and local weather data. Accurate location means accurate forecasts.
Tips:
Prefer not to share your location?
You can manually enter your latitude and longitude coordinates. This gives you full control while still getting accurate forecasts.
Example: San Francisco is approximately 37.77 latitude, -122.42 longitude.
Find your coordinates
Type your city and we'll search for the latitude and longitude in decimal degrees.
Still unsure about a setting? Check your solar installer's paperwork or your inverter's display or monitoring app.
Is the forecast significantly off? If your actual solar production consistently differs from OnSun's prediction, we'd like to hear from you. Send screenshots of your solar app alongside OnSun's forecast, along with your configuration details and location. This data helps us improve the forecasting model.
For accurate solar forecasts, OnSun needs your approximate location to calculate sun angles and local weather conditions. The app requests location permission when you first set up. You can update your location at any time in Settings. If you prefer not to share your precise location, you can manually enter your coordinates.
Find your coordinates
Type your city and we'll search for the latitude and longitude in decimal degrees.