Solar maps and data
Measuring solar exposure
The quality of solar exposure varies widely according to time of day and season. To estimate solar exposure, researchers:
- model the sun’s position
- use satellite imagery to estimate the impact of cloud cover
- check the results against recordings at weather stations on the ground.
Solar exposure comes in two forms:
- direct solar radiation – direct beams hitting the earth’s surface in a straight line
- diffuse solar radiation – light reflected and refracted by the atmosphere, clouds and the ground, hitting the earth’s surface from a wide range of angles.
Solar photovoltaic energy systems use both direct and diffuse radiation (global solar exposure). Solar thermal (concentrating solar) energy systems use direct solar radiation alone.
Solar exposure data
The Bureau of Meteorology (BOM), the national weather agency, compiles solar exposure data for Western Australia. BOM provides:
- average solar exposure – national maps of average daily global solar exposure, for each month and annually, based on data from 1990 to 2008
- climate data online – time series data of daily global solar exposure for locations with weather stations
- data requests – for a small fee, you can order a DVD with hourly global and direct solar exposure data spanning 1998 to 2010. Data is suitable for GIS software and has a grid resolution of 0.05 degrees (approximately 5 km). You can also order daily direct and diffuse solar exposure recorded at weather stations.
- weather station directory – a summary of weather station locations in WA and the types of data that each records
BOM and Geoscience Australia are installing equipment to record global, direct and diffuse solar exposure at a further eight weather stations (making 17 in total), including three in WA. This expansion is part of a national improvement program and new mapped solar data should be available from mid-2013.
Solar studies on the Wheatbelt
WA’s Wheatbelt Development Commission contracted University of Western Australia researchers to investigate potential locations for concentrated solar thermal generation in the Wheatbelt. The study was funded through the Royalties for Regions initiative.
The study assessed solar resources, land availability and value, topography and access to roads, water and the electricity network. Detailed maps from the study show the best locations for solar thermal development in the region.
International direct solar radiation map
The World Resources Institute’s direct solar radiation map demonstrates WA’s excellent solar energy resources compared to those across the globe.