IEA (2012), "Technology Roadmap - Solar Heating and Cooling", IEA, Paris https://www.iea.org/reports/technology-roadmap-solar-heating-and-cooling
The solar heating and cooling roadmap outlines a pathway for solar energy to supply almost one-sixth (16.5 EJ) of the world’s total energy use for both heating and cooling by 2050. This would save some 800 megatonnes of CO2 emissions per year – more than the total CO2 emissions in Germany in 2009. While solar heating and cooling today makes a modest contribution to world energy demand, the roadmap envisages that if concerted action is taken by governments and industry, solar energy could annually produce more than 16% of total final energy use for low temperature heat and nearly 17% for cooling. Given that global energy demand for heat represents almost half of the world’s final energy use – more than the combined global demand for electricity and transport – solar heat can make a significant contribution in both tackling climate change and strengthening energy security.