Rooftop Rooftop Solar Forecasts

Solar power forecasting for rooftops - just one, or thousands. PV Tuning technologies adapt to local conditions.

Solar power forecasts for rooftop sites via API

Connecting your rooftop site with our rapid-update cloud nowcasting system and delivering 30 minute resolution power forecasts out through 7 days ahead via our API. Set-up your test site within minutes!

  • Capture Shading Impacts
  • Detect Degradation, Estimate Tilt
  • Identify Azimuth Angles
  • Individualise Cloud Impacts
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PV Tuning: Forecasting for your PV system

Shading? Soiling? Split arrays? Unsure of system specs? No problem! Take advantage of our PV tuning technology, which learns from your shared power measurements to individualise the forecast. Use our API to automatically POST your past and/or live measured data data directly to our API. Once you’ve posted more than about 4 to 6 weeks of data, tuning will be applied to your rooftop site.

Proven customer use cases for rooftop solar forecasting:

  • Accurately plan and manage home energy use around solar intermittency

  • Optimising charge/discharge of home energy storage systems

  • Managing peak demand charges for large commercial energy users

  • Enable smart energy trading strategies across rooftop solar portfolios

  • Conduct DIY experiments or build new products/apps

  • Conduct research (Solcast offers free access to this product for non-commercial use)

Features and benefits

  • Power production Forecast (now to +7 days) and Live (-7 days to now) estimated actuals data
  • Choice of lat/lon based API requests, or via creation of rooftop site (allows tuning)
  • Global coverage, use one API wherever you operate
  • PV Tuning: captures the impacts of shading or other de-ratings from your measurement data
  • Privacy agreement for your shared measurement data, ability to permanently delete


Data Specifications


PV Power (kW)

Forecast probabilities

10th and 90th percentile forecasts provided for: PV Power (kW)

Spatial coverage

All continents (Rapid update actuals and forecast data) Global (forecasts)

Time granularity

Rooftop Sites or via Simple Lat/Lon PV Power requests: 30 minutes (period mean)

Update frequency

Every 10 or 15 minutes

Time span (Forecast)

Present time to +7 days ahead

Time span (Live)

7 days ago to present time

Power modelling – Included Metadata options

Maximum installed capacity

2,000 kW

Tracking systems supported?


Minimum metadata you need to provide

latitude, longitude (and capacity, if you don’t upload or post measurements)

Additional metadata you can share for better forecast

azimuth, tilt, AC capacity, DC capacity, loss factor, install date

Multiple tilts/tracks supported?

No. You can create and group multiple sites, or you can use tuning.

Power modelling - Included tuning options

Detects your site specifications from measured data?


Learns about shading, slope and other site-specific factors?


Minimum period of measurement data required to start improving your forecast with tuning

2 months (12 months is ideal)

Minimum measured data parameters we require

Total power output (kW)

Allowable time granularity of your measured data

Live data posting to Solcast API:

  • 5 to 30 minutes (5 minute means every 5 minutes is ideal)

Automated HTTP post of live or recent measured data to our API, for continuously updated tuning and live accuracy tracking?


Privacy agreement for your measurement data?


Ability to permanently delete your measurement data?


API call options

Your choice of either:

  • Lat/lon based Simple Lat/Lon PV Power requests (allows greater flexibility)
  • Creation of weather site (allows for tuning, measurement upload and site management)

Check it out for yourself, add a rooftop site and start testing

You can get started now by signing up for our API, and then adding your site location, a name and a few basic details about its technical specifications.

Or, just start making lat/lon based API PV Power requests.

Verified residential home hobby users will receive an additional free daily API request allowance (for their single home site only).