A solar power technology that captures heat using mirrors to focus sunlight toward liquid-filled pipes or a centrally located 'power tower' is known as a

• A. PV solar panel
• B. Solar thermal collector
• C. Concentrated solar thermal (CST) plant
• D. Solar chimney

Answer: (C)

Concentrated solar thermal (CST) plants use mirrors to focus sunlight onto a receiver containing a heat-transfer fluid in pipes or onto a central receiver on a tower. That focused heat is used to generate steam, which drives a turbine to produce electricity. The distinctive feature here is the concentration of sunlight to heat a fluid rather than converting sunlight directly to electricity with semiconductors, as PV panels do. This setup with mirrors or a tower and a liquid-filled receiver is what defines CST. Other options don’t fit: PV panels convert light directly to electricity; a general solar thermal collector can be non-concentrating and heat fluid without concentrating; a solar chimney relies on convection from heated air, not focused heat in pipes.