A solar concentrator is an optical device designed to capture solar energy incident over a large surface and concentrate it in a region of less area, with the aim of increasing the available energy density. This concentration can be achieved by reflection "Reflection (physics)") (using mirrors) or refraction (using lenses). Solar concentrators are used in applications that require high temperatures or high light intensity, such as concentrated solar thermal energy, Stirling engines or highly concentrated photovoltaic (CPV) systems.[1]​.

According to Ma et al. (2019), these systems "play an essential role in capturing solar energy, by effectively increasing the power density available for thermal or electrical conversion."[1]​.

The operation of a solar concentrator is based on the principles of geometric optics, redirecting the incident solar rays towards a point or focal line. To reflect, direct and concentrate solar radiation, solar reflectors are used, which must meet certain characteristics to guarantee the efficiency of the system:

At the focus, where the redirected solar rays converge, a receiver is located where the concentrated radiation is transformed into heat or electricity. This receptor normally consists of a solar absorbing material that must:

Solar receivers can be classified according to their design and form of energy collection:.

The efficiency of the system depends on the quality and receptivity of the optical surfaces, the precision of solar tracking, geometric alignment and thermal losses in the receiver.[5]​.

Studies such as De Lara (2013) on the sizing of Fresnel concentrators show that factors such as acceptance angle, dispersion and partial shadows significantly influence overall optical performance.[5] Concentrated radiation can heat thermal fluids (such as oils, molten salts or water) to temperatures greater than 400 °C, allowing their use in thermoelectric cycles or industrial processes.

There are various configurations according to their geometry, level of concentration and technological application:.

Each design presents advantages and limitations: while parabolic systems reach higher temperatures, LSCs stand out for their potential in architectural integration and low maintenance cost.[11]​.