World API subscriptions provide access to BOTH solar radiation and pv power output data.
The World API provides access to Solcast's Rapid Update cloud opacity and solar irradiance forecasts and estimated actuals. Further detail on the inputs and methods used to create these data is available on our website.
In summary, we use a combination of satellite imagery, weather models, aerosol data and state of the art algorithms to estimate the thickness of local cloud cover to sunlight (cloud opacity) and model how much solar radiation arrives at the Earth's surface (adjusted for local elevation).
The full list of available parameters and their definitions is available in this article.
Simple PV Power
The World API creates PV Power output estimated actual and forecasts, by running The World API solar radiation values through our Simple PV Power Model. This PV Power model is based on a modified version of the quadratic model, whose formulation and details can be reviewed in our CTO's 2017 publication: "QCPV: A quality control algorithm for distributed photovoltaic array power outputs". You can find it on ResearchGate at this link.
The World API's PV model requires several imports inputs from the user:
PV System tilt angle
PV System azimuth angle
PV System capacity (AC or DC capacity, whichever is greater)
Estimated loss factor (0 - 100%, where 100% is perfectly efficient)
You can find specific information about each of these inputs in the Solcast API documentation
The latitude and longitude location values input from the user are used to provide the requisite solar radiation and geometry inputs to the model (solar zenith, solar azimuth, ambient temperature, plane of array irradiance). These values are provide to the model, in addition to the tilt, azimuth, capacity and loss factor to produce PV power estimates for the 30-minute period.
These 30 minute values are a 30 minute average of instantaneous power output, timestamped to the end of the period (in UTC format).