Daggett, California in the context of Interstate 40 in California

A heliostat (from Ancient Greek ἥλιος (hḗlĭos) 'sun' and στατός (stătós) 'standing')is a device that reflects sunlight toward a target, turning to compensate for the Sun's apparent motion.The reflector is usually a plane mirror.

The target may be a physical object, distant from the heliostat, or a direction in space. To do this, the reflective surface of the mirror is kept perpendicular to the bisector of the angle between the directions of the Sun and the target as seen from the mirror. In almost every case, the target is stationary relative to the heliostat, so the light is reflected in a fixed direction. According to contemporary sources the heliostata, as it was called at first, was invented by Willem 's Gravesande (1688–1742). Other contenders are Giovanni Alfonso Borelli (1608–1679) and Daniel Gabriel Fahrenheit (1686–1736). A heliostat designed by George Johnstone Storey is in the Science Museum Group collection.

Solar Energy Generating Systems (SEGS) is a concentrated solar power plant in California, United States. With the combined capacity from three separate locations at 354 megawatt (MW), it was for thirty years the world's largest solar thermal energy generating facility, until the commissioning of the even larger Ivanpah facility in 2014. It was also for thirty years the world's largest solar generating facility of any type of technology, until the commissioning of the photovoltaic Topaz Solar Farm in 2014. It consisted of nine solar power plants in California's Mojave Desert, where insolation is among the best available in the United States.

SEGS I–II (44 MW) were located at Daggett (34°51′45″N 116°49′45″W / 34.86250°N 116.82917°W / 34.86250; -116.82917); they have been replaced with a solar photovoltaic farm.