Factsheet on Concentrated Solar Thermal (CST) Concentrated Solar Thermal (CST) is a promising renewable technology that concentrates solar radiation to achieve high solar fluxes and obtain high temperatures. In the case of solar tower systems, large mirrors, known as heliostats, are used to collect sunlight and reflect its rays onto a central solar receiver. By concentrating sunlight, CST can heat up a heat transfer fluid or a particle heat carrier to produce high-temperature heat. This carrier then delivers the thermal power to downstream processes for industrial heating, for driving chemical reactions or for electricity generation (being referred in this case as CSP, concentrated solar power). CST can play a pivotal role in the global push towards industrial decarbonisation, especially in hard-to-electrify sectors, and also support the defossilisation of the industry by generating renewable feedstocks for the circular economy.