"Thermal power" refers to the energy that is generated from heat. It involves converting heat energy into mechanical or electrical power. Full definition
Solar thermal power plants use concentrating solar collector systems because they can produce high temperature heat. (eia.gov)
Solar thermal power plants provide consistent power output and the ability to incorporate storage, but there are dark clouds on the horizon. (greentechmedia.com)
That reserve would be covered by thermal power station units backed off sufficiently in load to immediately pick up if required. (co2insanity.com)