Grid size Australia



First of all, I really appreciate all the work you guys have done to make this available to everyone! Secondly, I was interested in what the grid size is of the radiation forecasts. Does this grid size depend on the resolution of the satellite images?

Thanks in advance!


Hi Marijn,

The radiation forecast data is based on 1-2km resolution satellite imagery for near term forecasting (nowcasts), further out is based on numeric weather models and some ML. This comes directly from what resolutions we can get from the weather satellites.

Currently we use:

GOES16 for North + South America
GOES 15 for Hawaii, some of Alaska (this will be replaced by up coming GOES17 due early next year)
Multiple Meteosat satellites for Africa, Europe and West Asia
Himawari-8 for East Asia, Australia and New Zealand

The coverage map below is still accurate until GOES17 comes online.

Hope that helps!


Hi Darren,

Thanks a lot for the fast response! If you don’t mind, I have a few more questions ^^

  • For what time range do you use satellite imagery?
  • What kind of algorithms do you use to make the predictions from the satellite imagery? Are you using the Heliosat 2 method to determine the solar irradiance and AMV’s to predict the movement of the clouds or other algorithms?
  • What is the liming factor for the 0.5 hour time step? Are there any plans to go to a smaller time step?

Thanks again!


1- Time ranges are from satellite providers as they sample at those rates (The age+resolution detail of a satellite determines its sampling rate i.e. GOES16 does 15 minute intervals at high resolution for North/South America). Satellite imagery is processed 24 hours a day, every day as it is received.
2 - Would need to check with others if this is going to be published or outlined, I suggest directing this question to preferred contacts on Solcast homepage:

Please direct enquiries to James Luffman
or Nick Engerer

3 - The current 30 minute timestep is an interval that can be standardized across all current satellite domains. Smaller timesteps are available for utility scale customers (academic qualifications would need to be again directed to preferred Solcast contacts) that have provided data for tuning that will allow for interpolation on finer time scales down to 5 minutes forecast power availability


@MarijnKalter I’ll let some one from our modelling team answer the first question regarding methods used, but some clarity around time steps and latency for our forecasts.

  • Images start to be processed very soon after becoming available from down stream providers (generally < 1 minute)
  • Latency for results varies per satellite domain due to size.
  • New forecasts and observations are made every satellite time step (see global map image above again for different time steps)
  • Data processed for each time step available via the API usually within 1-5 minutes of the imagery becoming available, mainly depending on size of domain.


Thank you both a lot for the explanations!