Frequently Asked Questions

The basics

Q: What is the Solcast API?

A: The Solcast API is a solar radiation and solar energy forecasting data service that is designed to be easy to use and to integrate with other systems that are looking for live solar radiation and solar PV energy output data. We’ve built this SaaS (Software-as-a-Service) offering to enable with the smooth transition to high penetrations of solar energy generation. For a good introduction to the types of data we offer, and what our data looks like, the best place to start is to register and then browse the Solcast API Toolkit

Q: What does the Solcast API do?

A: Our API provides data from up to 12 years back up to real time, and then also ahead a week ahead. It provides Solar PV power production and Solar Radiation and Weather data. Coverage is global for Forecasts. Inside satellite coverage areas (all continents except Antarctica) our Historical, Recent and Live estimated actuals are available. Our forecasts update every 10 or 15 minutes in these areas, too.

Q: How much does it cost?

A: See our Pricing page. You can start on our Free plan while you are testing, then you have Paid plan options or you can request an Enterprise quote. Our pricing policy is consistent with our aim to make solar data easy to access. Public researchers receive additional free historical data credits, and home hobbyists receive additional free plan forecast API call allowances.

Q: I’d like to use the Solcast API, how do I get started?

A: First you need to sign-up for an API key by creating an account via our API registration page. You’ll be logged into our easy to use Solcast API Toolkit, which works in your web browser.

Q: What’s an API? And what is an API key, and how do I use it?

A: API stands for “Application Programming Interface”, by using our API, you can access our data – for inclusion in your application or to download in a standard format for desktop analysis. In order to access our servers, you need a key, which is unique to your account.

Q: I’d like to try out the API, are there any examples or demos available?

A: Yes! On our home page you can see sample graphics of some of our live API data. In our API Pages you can see example API calls, plus variable names and protocols for the API. More details can be found in our API Docs

The data

Q: Where does the radiation data come from?

A: We fuse a wide range of data sources together, based on the best and latest peer-reviewed science. Our data sources include satellite data, real-time PV output data, records of installed PV, surface radiation data, and numerical weather models. We routinely validate our data and refine our models to maximise the accuracy.

Q: How are the PV power estimates derived?

A: We use proprietary power modelling methods, which are based on the characteristics of the system, radiation parameters, solar geometry and temperature. Our models are routinely tested on real PV system output and constantly refined.

Q: What values of solar radiation are provided by the API?

A: We provide the GHI (global horizontal), DNI (direct normal) and diffuse (horizontal) values of solar radiation. Read more on the Solar Radiation Data page.