We are happy to announce that we are extending our weather data sets from 2022 to include 2023. We have had many inquiries about 2023 weather data, but our most trsuted solar data source, the Bureau of Meteorology (BoM)’s gridded solar data was undergoing its routine Quality Assurance (QA), so we were not able to fulfil those requests until now.
Finally, BoM has disseminated gridded solar data by daily, hourly and 10 minutely to the end of December 2023. The data is updated monthly with 3-4 month data latency. We used 2023 solar irradiance data from Solcast for the 8 capital cities for our Real Time Years (RTYs) and the Exemplary Weather and Index analysis based on it because of this latency. Comparison of the real-time data stream from Solcast with the BoM’s QAed equivalent will be an integral part of that work.
We’re currently processing gridded solar data from BoM to quality-assess the 2023 solar data for the eight capital cities. Following this, we’ll be updating data for other sites for the 34 years from 1990 to 2023. If you have interests in the 2023 weather data outside the 8 capital cities, please contact us at exemplary.energy@exemplary.com.au to change production priority. On a rolling as-completed basis, the updated data sets will be made available through our sales portal.
Abstract of the Gridded Solar Data
The Bureau of Meteorology employed the Heliosat-4 radiation model (Qu et al, 2017) as implemented by Mines ParisTech (Gschwind et. al., 2020) to estimate downwelling solar radiation parameters. Heliosat-4 uses estimates of cloud properties derived from satellite observations, estimates of aerosol optical depth, and forecasts of atmospheric ozone and water vapour to estimate instantaneous surface global solar irradiance (known as global horizontal irradiance, GHI) in units of W m-2. Heliosat-4 also produces estimates of the instantaneous intensity of surface direct horizontal irradiance (BHI) in units of W m-2, from which the solar direct beam radiation falling on a surface normal to the beam (known as the direct normal irradiance, DNI, with units W m-2 is calculated.
A bias correction scheme was developed and applied to remove systematic biases in GHI and BHI which can arise from biases and uncertainty in observations, auxiliary products used in the Heliosat-4 forward model, and/or the Heliosat-4 forward model itself. The surface diffuse horizonal irradiance (DIF) is calculated as the difference between GHI and BHI with units of W m-2.
GHI, DNI and DIF are calculated every 10 minutes between sunrise and sunset for each day for the Australian continent, bounded by 112-156.26°E and 10-44.5°S. These 10-minutely observations are integrated with respect to time to produce the daily integral of surface global irradiance (daily_integral_of_surface_global_irradiance, commonly referred to as “daily exposure”), daily integral of direct normal irradiance (daily_integral_of_direct_normal_irradiance) and the daily integral of surface diffuse irradiance (daily_integral_of_surface_diffuse_irradiance). The number of observations during daylight hours (number_of_observations), and the number of these observations classified as cloud (number_of_cloud_ observations) are also provided.