Rooftop Rooftop Solar Forecasts

Solar power forecasting for installations below 1MW in size. Includes free access for your home PV system.

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Power forecasts for rooftop solar installations using the latest satellite data, worldwide

Rooftop Solar Solcast gathers the latest satellite imagery from five weather satellites in order to model and forecast PV power generation across the planet. Every 5-15 minutes we detect the latest cloud cover conditions nearby your rooftop power generation site(s), and run sophisticated prediction algorithms to anticipate where the cloud cover will move next. Using PV power modelling tools, we convert the predictions of local cloud cover into forecasts of power output from each Rooftop PV system registered in our API Toolkit.

Setup a free test site

Access to Rooftop Solar Forecasts

To access Rooftop Solar PV forecasting data, start by creating a free account in our API Toolkit. We include both ‘commercial’ user and ‘home PV system’ account types, and will provide free forecasting data for your personal rooftop solar installation.

Upon registration, you will have two options for retrieving Rooftop Solar data.

Solcast API Toolkit Option 1: The first way to access the data are Rooftop Solar Sites.

Upon login to the API Toolkit, navigate to the “Rooftop” section and select “Add site”.

This action will prompt you to add some basic information about your Rooftop Solar PV installation. This includes the name, location, capacity and installation date. Once completed, this will trigger the creation of a new ‘site’ in our API system, which you can use to instantly retrieve both live (real-time back through 7 days) and forecast (present time to 7 days ahead) power output estimates at 30 minute time resolution.

Option 2: World API

For users who have a large number of sites, or whose locations of interest change over time, and don’t have a need to upload measurement data, our World PV Power API may be of interest.

With this data product, users can instantly retrieve live or forecast PV power data from anywhere in the world at 30-minute resolution using a location (latitude and longitude) and basic PV system information (AC capacity, efficiency factor, azimuth, tilt). The World API still receives rapid update service, with new data flowing into the forecast and live data with each new satellite scan.

Pricing for the World API starts at $370 USD / month for 10,000 API requests, and your first month is free. The World API also includes access to solar irradiance data, and you can add 10,000 API requests for only $2OUSD each. See our pricing page for more details.

Data Specifications

In the table below are our indicative specifications. Once you’ve created your free API Toolkit account and first Rooftop Solar Site, you’ll be able to download our data for testing and review our detailed API documentation.

Rooftop Solar Sites (Home PV System) World PV Power API
Locations Fixed Flexible
Prices Free for your verified home residence $370 USD / month
Pricing model 10 API requests per site per day Flat fee for 10,000 API requests
Add 10,000 requests for $20
Parameters Live & Forecast:
  • PV Power (MW)
  • UTC timestamp (period end, period start)
Forecast Only:
  • PV Power (PvEstimate10, PvEstimate90) - 10th percentile and 90th percentile
Time Resolution 30 minutes
Update Frequency Every 5-15 minutes (Rapid Update)
Timespan Live:
7 days ago to present time
Present time to +7 days ahead
Coverage All continents (except Antarctica)
File Format CSV JSON XML

Site Specifications - Rooftop Solar Sites

To enable the Rooftop Solar Sites product for your site, we’ll require some information about your system layout, including its AC/DC capacity and installation date.

Rooftop Solar Sites World PV Power API
Required latitude, longitude, DC and AC capacity, azimuth, tilt latitude, longitude, AC capacity
Optional Installation date, efficiency factor azimuth, tilt, efficiency factor
Measurement Data Parameters Required
Total power output (MW)
Timestamp (UTC)
Does not apply
Measurement Data Period 6 weeks minimum
12 months optimal
Does not apply
Measurement Data Resolution 30 minutes (maximum)
10 minutes (optimal)
5 minutes (minimum)
Does not apply

Access to Solcast’s Rooftop Solar data is just a few clicks away

Screenshot from Solcast API Toolkit It’s our aim to make access to high quality solar power forecasting easy and straightforward. With our API Toolkit, you are only a few clicks away from creating your own free account. Create your own Rooftop Solar site, watch the power output forecast graphs change in real-time and upload your measurement data to improve the predictions. The API Toolkit makes it easy to learn about how to retrieve the data you need from our APIs.

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).