A solar plant that stores heat, not sunlight
A tower-based solar plant uses mirrors to concentrate sunlight on a receiver high above the field. The receiver transfers that intense heat to a flowing salt mixture. The salt is kept hot enough to stay liquid, so it can move through pipes and carry energy to storage tanks.
That distinction matters: the plant does not save sunlight itself, or necessarily store electricity in batteries. It stores thermal energy—heat captured while the sun is shining.
From hot salt to nighttime power
During sunny hours, heated salt is directed into an insulated hot-storage tank. When the plant needs to generate electricity later, the salt passes through a heat exchanger, a device that transfers heat between fluids without mixing them. It heats water into steam, and the steam spins a turbine connected to a generator.
After giving up some of its heat, the salt returns to a cooler tank. When sunlight is available again, it can be heated and sent back to the hot tank. This circulating arrangement lets the solar field and the power-generating equipment operate on different schedules: the mirrors collect energy by day, while stored heat can drive the turbine after sunset.
Why store heat before making electricity?
The process gives a solar plant a way to shift part of its output beyond daylight without first converting the captured energy into electricity and then back again for storage. The stored heat still has to be turned into steam and electricity when needed, but the same turbine system can keep working after the mirrors stop receiving direct sun. In practical terms, sunset ends collection—not necessarily generation.
