In the late 1950s, solar cells were adopted by NASA to power satellites. The space industry's pioneering of solar technology for use in spacecraft has contributed to the advancement, reliability, and cost effectiveness of solar technology. PV panels are most commonly seen on rooftops and walls, but nowadays, anything from clocks, watches, calculating, road signs and bus shelters to houses and commercial buildings can run on power generated by PV system. Areas of PV arrays known as solar farms produce electricity on a scale large enough to be distributed through a power grid to thousands of homes. The world's largest solar farm, Waldpolenz Solar park near Leipzig, Germany, covers 110 hectares and uses state-of-the-art thin-film photovoltaic technology to produce 40,000 megawatts (MW) of electricity.

Concentrating solar power (CSP) uses large mirrors or receiving collectors to concentrate the sun's radiation on pipes, tubes, or cylinders filled with fluid or gas. An intense heat of 160° to 540°C (300° to 1,000°F) creates steam or expands gas to drive a turbine or electricity generator. High-temperature collectors, such as giant parabolic dishes covered with mirrors, generate large amounts of electricity that is fed into a power grid. In the 1980s, nine thermal solar power plants with a combined capacity of 354 MW were built in the Mojave Desert. The Ivanpah Solar Power facility, which is still under construction in the south-western United States, will have a combined capacity of 392 MW.

Another form of collector technology is solar thermal energy, which heats swimming pools and household water. The first solar water heater was patented in the United States in 1891, and by 1897, nearly a third of the homes in Pasadena, California, had installed a solar water heating system. Interest in these system revived in the late 1970s, but in the mid-1980s, their popularity declined with energy prices and the expiration of federal tax credit.

The main work of large mirror or receiving collectors in the thermal solar power is to.

Concentrate sun's radiation

The correct answer is Option (2) → Concentrate sun's radiation

These collectors focus sunlight onto a small area, typically using mirrors or lenses, to generate intense heat. This concentrated solar energy is then used to heat a fluid or gas, which, in turn, can be used to produce steam and drive a turbine or generator to generate electricity. The concentration of sunlight is a crucial step in maximizing the efficiency of solar thermal power systems.