Concentrating Solar Power (CSP) uses mirrors to reflect and concentrate sunlight onto receivers that collect solar energy and convert it to heat. Thermal energy can then be used to produce electricity via a turbine or heat engine driving a generator.
Because CSP technologies collect solar energy and convert it to thermal energy that power a generator and be stored, they can be used either as a flexible provider of electricity, such as a natural gas “peaker” plant, or as a baseload source of electricity similar to a traditional nuclear or coal plant. CSP can also be deployed as fossil-fuel backup/hybridization that allows existing fossil fuel projects to run cleaner while operating at the same or lower cost.
This video is from The US Department of Energy.