What is the role of heliostats in a power tower system?

Concept:

In a power tower system (central receiver system), heliostats are flat, sun-tracking mirrors used to reflect and focus sunlight onto a central receiver mounted on a tower. The concentrated sunlight heats a working fluid, which is then used to generate electricity through a heat engine or steam turbine.

Given

Component: Heliostats

System: Solar power tower

Calculation

The primary function of heliostats is to follow the movement of the Sun throughout the day (using a dual-axis tracking system) and continuously reflect sunlight toward the central receiver. This ensures maximum solar energy concentration at the receiver.

Other options like storing energy, converting thermal to electrical energy, or direct electricity generation are handled by different components in the system, not the heliostats.

Final Answer: To track the Sun and direct sunlight to the receiver