Solar thermal energy in the context of "Photovoltaic systems"

A photovoltaic system, also called a PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and convert sunlight into electricity, a solar inverter to convert the output from direct to alternating current, as well as mounting, cabling, and other electrical accessories to set up a working system. Many utility-scale PV systems use tracking systems that follow the sun's daily path across the sky to generate more electricity than fixed-mounted systems.

Photovoltaic systems convert light directly into electricity and are not to be confused with other solar technologies, such as concentrated solar power or solar thermal, used for heating and cooling. A solar array only encompasses the solar panels, the visible part of the PV system, and does not include all the other hardware, often summarized as the balance of system (BOS). PV systems range from small, rooftop-mounted or building-integrated systems with capacities ranging from a few to several tens of kilowatts to large, utility-scale power stations of hundreds of megawatts. Nowadays, off-grid or stand-alone systems account for a small portion of the market.

A steam turbine or steam turbine engine is a machine or heat engine that extracts thermal energy from pressurized steam and uses it to do mechanical work utilising a rotating output shaft. Its modern manifestation was invented by Sir Charles Parsons in 1884. It revolutionized marine propulsion and navigation to a significant extent. Fabrication of a modern steam turbine involves advanced metalwork to form high-grade steel alloys into precision parts using technologies that first became available in the 20th century; continued advances in durability and efficiency of steam turbines remains central to the energy economics of the 21st century. The largest steam turbine ever built is the 1,770 MW Arabelle steam turbine built by Arabelle Solutions (previously GE Steam Power), two units of which will be installed at Hinkley Point C Nuclear Power Station, England.

The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of the steam, which results in a closer approach to the ideal reversible expansion process. Because the turbine generates rotary motion, it can be coupled to a generator to harness its motion into electricity. Such turbogenerators are the core of thermal power stations which can be fueled by fossil fuels, nuclear fuels, geothermal, or solar energy. About 42% of all electricity generation in the United States in 2022 was by the use of steam turbines. Technical challenges include rotor imbalance, vibration, bearing wear, and uneven expansion (various forms of thermal shock).

Concentrated solar power (CSP, also known as concentrating solar power, concentrated solar thermal) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight into a receiver. Electricity is generated when the concentrated light is converted to heat (solar thermal energy), which drives a heat engine (usually a steam turbine) connected to an electrical power generator or powers a thermochemical reaction.

As of 2021, global installed capacity of concentrated solar power stood at 6.8 GW. As of 2023, the total was 8.1 GW, with the inclusion of three new CSP projects in construction in China and in Dubai in the UAE. The U.S.-based National Renewable Energy Laboratory (NREL), which maintains a global database of CSP plants, counts 6.6 GW of operational capacity and another 1.5 GW under construction. By comparison, solar power reached 1 TW of global capacity in 2022, of which the overwhelming majority was photovoltaic.

Solar energy is the radiant energy from the Sun's light and heat, which can be harnessed using a range of technologies such as solar electricity, solar thermal energy (including solar water heating) and solar architecture. It is an essential source of renewable energy, and its technologies are broadly characterized as either passive solar or active solar depending on how they capture and distribute solar energy or convert it into solar power. Active solar techniques include the use of photovoltaic systems, concentrated solar power, and solar water heating to harness the energy. Passive solar techniques include designing a building for better daylighting, selecting materials with favorable thermal mass or light-dispersing properties, and organizing spaces that naturally circulate air.

In 2011, the International Energy Agency said that "the development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. It will increase countries' energy security through reliance on an indigenous, inexhaustible, and mostly import-independent resource, enhance sustainability, reduce pollution, lower the costs of mitigating global warming .... these advantages are global".

The Heliotrope is an environmentally friendly housing project by German architect Rolf Disch. There are three such buildings in Germany. The first experimental version was built in 1994 as the architect's home in Freiburg im Breisgau, while the other two were used as exhibition buildings for the Hansgrohe company in Offenburg and a dentist's lab in Hilpoltstein in Bavaria.

Several different energy generation modules are used in the building including a 603 sq ft (56.0 m) dual-axis solar photovoltaic tracking panel, a geothermal heat exchanger, a combined heat and power unit (CHP) and solar-thermal balcony railings to provide heat and warm water. These innovations along with the favorable insulation of the residence allows the Heliotrope to capture anywhere between four and six times its energy usage depending on the time of year. The Heliotrope is also fitted with a grey-water cleansing system and built-in natural waste composting.

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.