1. http://solargis.com/assets/graphic/free-map/DNI/Solargis-World-DNI-solar-resource-map-en.png.
2. Renewable Energy, IEA Medium-term market report 2016, Market Analysis and Forecasts to 2021,Singapore International Energy Week,Singapore, Oct 25, 2016;http://www.siew.sg/docs/default-source/event/mtrmr_2016_launch_presentation_final.pdf.
3. http://reneweconomy.com.au/solar-fuels-could-be-australias-biggest-energy-export-59042/.
4. A general framework for the assessment of solar fuel technologies