A new generation of power plants called Concentrating Solar Power (CSP) that uses the sun as a heat source to generate electricity is on the rise. The first subsystem in a CSP plant are large mirrors that collect and concentrate the sunlight onto a fluid carrying receiver, hence the name solar collector or solar concentrator. These solar concentrators accurately track the sun daily and yearly to maintain high energy yield. In this talk, the function of solar concentrators and the different types of concentrators that are used in CSP will be discussed. A typical concentrator is composed of glass and silver reflector. For a 100 MW (electrical) power plant about 1,000,000 square meters of mirror reflective area is needed. To reduce cost, improve on the optical performance, and relax the tracking requirements, a new type of concentrator is being developed which uses dielectric metastructures. A background on this latest technology for solar applications will be provided.