Special Issue "Concentrated Solar Energy for Materials"

Energy is essential for almost all of the great challenges and opportunities that humankind faces today. However, energy is the main contributor to climate change, and accounts for around 60% of all global greenhouse gas emissions. In 2015, all of the United Nations Member States accepted the 2030 Agenda on Sustainable Development, an opportunity for countries and their societies to take action so as to improve the lives of all of the world's inhabitants. In this sense, one of the targets of the Agenda is to, by 2030, substantially increase the share of renewable energy in the global energy mix, and to achieve the sustainable management and efficient use of natural resources. In general, the processes of the synthesis and transformation of materials demand an extraordinary energy input in order to reach the high temperature required to complete the different chemical and physical reactions involved. This energy requirement is mainly provided from fossil fuels, with the consequent environmental costs derived from the high emissions of greenhouse gasses. Thus, nowadays, the level of concentration of CO2 into the atmosphere exceeds of 400 ppm. During the last decades, studies have been carried out to reduce the high level of CO2 emissions by developing new high-temperature processes. A large number of technologies are available for producing heat from renewable resources, but many of them have technological limits in terms of the maximum temperature that can be achieved. Nevertheless, concentrating solar thermal radiation is a very promising renewable energy resource for the processes requiring temperatures of about 500 °C and above