All articles starting with S
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Solar irradiance
Solar irradiance, also called solar flux, is the power per unit area of radiation from the Sun, measured in watts per square meter and averaging 1361 W/m² at the top of Earth's atmosphere.
Solar irradiance forecasting
Solar irradiance forecasting is the prediction of solar radiation reaching the ground over horizons from minutes to several days, underpinning photovoltaic power forecasting and grid operation.
Solar irradiance variability
Solar irradiance variability is the variation over time of the Sun's radiant power at Earth, averaging about 1361 W/m² and fluctuating roughly 0.1% over the 11-year solar cycle.
Solar luminosity
Solar luminosity is the total rate at which the Sun emits energy, about 3.828×10²⁶ watts; astronomers use it as a standard unit for expressing other stars' power output.
Solar magnetic field
The solar magnetic field is the magnetic field generated inside the Sun by a dynamo, producing sunspots and flares, with polarity reversing roughly every 11 years.
Solar mass
The solar mass (M☉), also called the mass of the Sun, is about 1.989 × 10^30 kg, roughly 333,000 Earth masses, and the standard unit for stellar, planetary, and black hole masses in astronomy.
Solar Maximum Mission
The Solar Maximum Mission, known as SolarMax, was a NASA solar observatory launched in February 1980 that observed solar flares and was repaired in orbit in 1984, the first such servicing.
Solar modulation
Solar modulation is the change in the intensity and energy spectrum of galactic cosmic rays as they pass through the heliosphere, following the Sun's 11-year activity cycle.
Solar neutrino
A solar neutrino is an electron neutrino produced by hydrogen fusion in the Sun's core. Their observed deficit, the solar neutrino problem, was solved by neutrino oscillations.
Solar neutrino problem
The solar neutrino problem, also called the solar neutrino deficit, was the decades-long shortfall of solar neutrinos detected versus predictions, first seen around 1970 and resolved by 2002 as evidence that neutrinos change flavor.
Solar One (Barstow, California)
Solar One was a 10 MW solar thermal power tower pilot plant near Barstow, California, operated from 1982 to 1988 by the Department of Energy and utility partners.
Solar Opposites
Solar Opposites: Hulu adult animated sci-fi sitcom by Justin Roiland and Mike McMahan (Rick and Morty), 2020-2025, six seasons, aliens from Shlorp in suburbia, the Pupa, The Wall subplot, Korvo recast to Dan Stevens.
Solar Orbiter
Solar Orbiter is a Sun-observing spacecraft of the European Space Agency with NASA participation, launched in 2020 to study the Sun from as close as 42 million km.
Solar panel
A solar panel, also called a solar PV module, is an assembly of solar cells sealed between protective layers that converts sunlight directly into electricity.
Solar particle event
A solar particle event, also called a solar proton event, is an intense burst of energetic particles from the Sun, associated with solar flares and coronal mass ejections.
Solar pond
A solar pond is a body of water that collects and stores solar energy as heat, typically using a salt gradient that traps warm, salty water at the bottom.
Solar power
Solar power, also called solar electricity, converts sunlight into electricity through photovoltaic cells or concentrating solar-thermal systems, and is now the fastest-growing source of new electricity capacity.
Solar Power (album)
Solar Power is Lorde's third studio album, released 20 August 2021 on Republic and produced with Jack Antonoff and Malay. An acoustic, folk-tinged departure from Melodrama, it scored 69 on Metacritic and divided critics.
Solar power by country
Solar power by country covers how photovoltaic capacity and generation are distributed worldwide. By 2025 global PV capacity reached 2.96 TW, and solar supplied 8.7% of global electricity, led by China.
Solar power in China
Solar power in China generates electricity from photovoltaic panels and concentrated solar thermal plants; China holds the largest installed capacity, manufacturing industry, and annual market.
Solar power in Germany
Solar power in Germany is electricity from photovoltaic systems, reaching 117 GW of installed capacity by the end of 2025, one of two pillars of renewables alongside wind.
Solar power in India
Solar power in India, also known as solar energy in India, grew from 2.82 GW of installed capacity in 2014 to 105.65 GW by March 2025.
Solar power in Japan
Solar power in Japan is the generation of electricity from photovoltaic systems, which grew rapidly after the 2012 feed-in tariff and supplied 9.2% of Japan's electricity in FY 2022.
Solar power in the United States
Solar power in the United States, also called solar energy in the United States, converts sunlight into electricity through photovoltaic panels and solar-thermal plants, supplying about 7% of utility-scale generation in 2025.
Solar power tower
A solar power tower is a concentrating solar power plant whose heliostat mirrors focus sunlight on a receiver atop a central tower to generate electricity.
Solar process heat
Solar process heat, also called Solar Heat for Industrial Processes (SHIP), is heat from solar thermal collectors supplied to industrial processes below about 250 °C.
Solar prominence
A solar prominence is a large, bright structure of cool, dense plasma extending from the Sun's surface into the hot corona, held by magnetic fields; many erupt, driving space weather.
Solar radius
The solar radius is the radius of the Sun, referred to its visible surface and about 695,700 km; it is also a standard unit for star sizes.
Solar sail
A solar sail, also known as a light sail, is a spacecraft propulsion method in which a large reflective membrane is pushed by sunlight pressure, giving propellant-free thrust.
Solar salt
Solar salt is a molten 60/40 blend of sodium and potassium nitrate used in concentrating solar power plants to store heat for generating electricity after sunset.