Solar
Solar is an adjective primarily denoting that which is of, derived from, relating to, or caused by the sun.[1][2] The word originates from Latin sōlāris, meaning "of the sun," which itself derives from sōl ("sun") and traces back to the Proto-Indo-European root *sáwel- or *sóh₂wl̥ signifying the sun.[3] Entering English in the 15th century, it initially carried connotations tied to solar phenomena and measurements, such as a solar year defined by Earth's orbit around the sun.[1] Historically, "solar" also functioned as a noun for an upper-story room in medieval buildings, likely due to its sunlit orientation.[3] In modern scientific and technical contexts, the term features prominently in astronomy, as in the solar system—the gravitationally bound collection of the Sun and orbiting celestial bodies named after the Latin sol for the central star; physics, referring to solar radiation as electromagnetic emissions from the sun; and engineering, particularly solar power, which converts sunlight into usable electricity via photovoltaics or thermal systems.[4][5] These applications underscore solar's foundational role in understanding cosmic structures, energy resources, and timekeeping, with empirical measurements of solar output—approximately 3.8 × 10²⁶ watts—driving advancements in fields from climate modeling to renewable technologies.[5] While uncontroversial in definitional scope, applications like solar energy generation have sparked debates over scalability, material dependencies (e.g., silicon and rare earths), and grid integration challenges, though first-principles assessments affirm sunlight's causal primacy as an abundant, zero-fuel-cost input.[6]Astronomy
Definition and Key Concepts
The Sun is the star at the center of the Solar System, classified as a G2V main-sequence star, commonly termed a yellow dwarf due to its spectral characteristics and color.[7] It exerts gravitational dominance over the system, holding planets, asteroids, and other bodies in orbit, while comprising approximately 99.86% of the total mass within the Solar System.[8] The Sun's equatorial diameter spans 1.392 million kilometers (865,000 miles), equivalent to about 109 Earth diameters, and its mean distance from Earth averages 149.6 million kilometers (92.96 million miles), defining one astronomical unit (AU).[7] Its estimated age is 4.6 billion years, derived from models of stellar evolution and isotopic dating of meteorites and lunar samples.[8] The Sun's composition by mass is dominated by hydrogen at roughly 74%, helium at 24%, and trace amounts of heavier elements (collectively about 2%), as inferred from spectroscopic analysis of its atmosphere and helioseismology probing the interior.[9] Structurally, it features a dense core extending to about 20-25% of its radius, where temperatures reach 15 million Kelvin and densities exceed 150 g/cm³, enabling sustained nuclear reactions; this is enveloped by the radiative zone, where energy transports outward via photon diffusion over millennia, and the convective zone, where plasma currents carry heat to the surface.[7] The visible surface, or photosphere, emits most of the Sun's radiant energy at an effective temperature of 5,500 Kelvin, appearing granular due to convective upwellings; above this lie the thinner chromosphere and the tenuous, million-degree corona, extending into the heliosphere.[9] Key to the Sun's stability and output is thermonuclear fusion in its core, primarily via the proton-proton (pp) chain, a sequence of reactions converting four hydrogen nuclei (protons) into one helium nucleus, releasing 26.7 MeV of energy per cycle, mostly as gamma rays that gradually thermalize outward.[10] This process accounts for the Sun's luminosity of 3.828 × 10²⁶ watts, sustaining its main-sequence phase for an expected total lifespan of about 10 billion years before evolving into a red giant.[7] The pp chain dominates in stars like the Sun due to core temperatures below 15 million Kelvin, contrasting with hotter stars reliant on the CNO cycle; observational confirmation stems from neutrino detections matching fusion predictions, resolving the historical solar neutrino problem through matter-enhanced oscillation effects.[10]Solar Phenomena and Activity
The Sun's activity is characterized by dynamic processes driven by its internal dynamo, which generates a complex magnetic field through the convective motion of plasma in the tachocline layer. This magnetic activity manifests in observable phenomena that vary over an approximately 11-year solar cycle, beginning with solar minimum—marked by few sunspots—and peaking at solar maximum with heightened eruptions and emissions.[11] Solar Cycle 25, which began in December 2019, reached its maximum phase in October 2024, as determined by NASA and NOAA analyses of sunspot numbers and radio flux metrics, leading to increased frequency of space weather events.[12] By September 2025, sunspot regions continued to show elevated activity, correlating with bursts of radiation and plasma ejections.[13] Sunspots are temporary, cooler regions on the photosphere appearing as dark patches due to intense magnetic fields inhibiting convection, typically measuring 10,000 to 50,000 km in diameter and lasting days to weeks.[14] These concentrations of magnetic flux serve as precursors to more explosive events, with their number rising from near zero at minimum to over 100 at maximum, as tracked by the International Sunspot Number index maintained by solar observatories.[15] Solar flares, intense bursts of electromagnetic radiation across X-ray to radio wavelengths, occur when tangled magnetic field lines near sunspots reconnect, releasing up to 10^32 ergs of energy in minutes—equivalent to billions of hydrogen bombs. Flares are classified by peak X-ray flux (e.g., X-class for the strongest, exceeding 10^-4 W/m²), and during Cycle 25's ascent, multiple X-class events were recorded, including eight in May 2024 alone. Coronal mass ejections (CMEs) represent large-scale expulsions of 10^12 to 10^13 tons of magnetized plasma from the Sun's corona, often triggered by flares or filament instabilities, traveling at speeds up to 3,000 km/s and expanding to span the Sun's diameter.[14] These events, observable via coronagraphs like those on NASA's SOHO and STEREO missions, can direct material toward Earth, inducing geomagnetic storms upon interaction with the magnetosphere.[18] Complementing these are solar prominences—dense, arched plasma structures suspended by magnetic fields—and the steady solar wind, a radial outflow of protons and electrons at 300-800 km/s, which carries the Sun's magnetic field into the heliosphere and modulates cosmic ray influx at Earth.[19] During periods of high activity, enhanced solar wind from coronal holes accelerates particles, intensifying auroral displays by channeling them along Earth's field lines into the ionosphere, where collisions with gases produce visible emissions peaking at 100-150 km altitude.[20] Solar activity influences Earth's environment through space weather, where CMEs and high-speed solar wind streams can compress the magnetosphere, inducing currents that disrupt power grids—as in the 1989 Quebec blackout from a Cycle 22 event—and degrade satellite electronics via radiation dosage exceeding 10^8 protons/cm².[21] Geomagnetic storms, quantified by the Kp index (up to 9 for severe events), have escalated in Cycle 25, with multiple G4-level storms in 2024 enhancing aurora visibility to mid-latitudes while posing risks to high-altitude aviation and GPS accuracy due to ionospheric scintillation.[22] Observations from missions like Parker Solar Probe confirm that these phenomena originate from the Sun's dynamo, with magnetic reconnection as the primary causal mechanism, rather than stochastic processes.[23]Historical Observations and Models
Ancient Chinese astronomers recorded the first documented sunspot observations around 800 BCE, with reliable written records dating to 28 BCE, often describing them as dark spots on the solar disk visible to the naked eye during total solar eclipses or under specific atmospheric conditions.[24] These sporadic sightings provided early evidence of solar surface variability, though systematic tracking was limited by the absence of optical aids. In contrast, Western records prior to the telescope remain unverified and less consistent, with possible ancient Greek mentions lacking confirmation.[24] The invention of the telescope in 1608 enabled direct telescopic scrutiny of the Sun, with Galileo Galilei conducting the first systematic observations in 1610, projecting the image to reveal sunspots and demonstrating the Sun's rotation period of approximately 27 days at the equator through their motion.[25] These findings challenged Aristotelian notions of celestial perfection, supporting Copernican heliocentrism by showing the Sun as a dynamic, imperfect body akin to planets.[26] By 1645–1715, during the Maunder Minimum, sunspot activity nearly ceased, correlating with cooler terrestrial temperatures in the Little Ice Age, though causation remains debated and not solely attributable to solar variability.[26] Samuel Heinrich Schwabe identified the approximately 11-year sunspot cycle in 1843 after decades of amateur monitoring, establishing a periodic pattern in solar activity.[27] Nineteenth-century spectroscopy advanced solar composition analysis; Joseph von Fraunhofer mapped dark absorption lines in the solar spectrum in 1814, and Gustav Kirchhoff explained them in 1859 as elemental signatures, revealing the Sun's atmosphere contains hydrogen, helium (predicted by Lockyer in 1868), and metals similar to Earth's.[28] Early energy models, such as Hermann von Helmholtz's 1856 gravitational contraction hypothesis, posited the Sun's luminosity arose from slow contraction releasing potential energy, yielding an age estimate of 20–30 million years—insufficient to reconcile with emerging geological evidence for an older Earth.[29] Twentieth-century models shifted to nuclear fusion following Arthur Eddington's 1920 advocacy for stellar energy from subatomic processes, though specifics eluded until Hans Bethe's 1939 elucidation of the proton-proton chain, enabling hydrogen-to-helium conversion in the core at temperatures around 15 million K, powering the Sun for billions of years.[29] The Standard Solar Model (SSM), formalized in the 1960s by incorporating hydrostatic equilibrium, energy transport via radiation and convection, and nuclear reaction rates, predicted neutrino fluxes that initially mismatched observations (the solar neutrino problem, resolved by neutrino oscillations in 2002).[29] Helioseismology, pioneered by Roger Ulrich in 1975 using Doppler shifts in solar surface oscillations, validated interior density and composition profiles, refining models against empirical p-mode frequencies.[25] These developments underscored the Sun's equilibrium as a main-sequence G-type star, evolving slowly over its 4.6-billion-year lifetime toward eventual red giant expansion.[7]Solar Technology
Principles of Solar Energy Conversion
Solar energy conversion transforms incident solar radiation—primarily photons in the visible and near-infrared spectrum—into electrical or thermal energy through physical processes governed by quantum mechanics and thermodynamics. The two dominant engineering approaches are photovoltaic (PV) conversion, which exploits the photoelectric effect in semiconductors to generate direct current electricity, and concentrating solar thermal (CST) conversion, which focuses sunlight to produce high-temperature heat for power generation. These methods capture a fraction of the solar constant, approximately 1366 W/m² at Earth's mean orbital distance, though terrestrial insolation averages 1000 W/m² under standard test conditions (AM1.5 spectrum).[30][31] In PV conversion, photons incident on a semiconductor material with energy greater than the material's bandgap excite electrons from the valence band to the conduction band, generating electron-hole pairs. A built-in electric field at the p-n junction separates these charge carriers, producing a photocurrent and voltage; silicon, with a bandgap of 1.1 eV, absorbs wavelengths up to about 1100 nm efficiently. Conversion efficiency is constrained by fundamental losses: sub-bandgap photons transmit unabsorbed, excess photon energy thermalizes as heat, and radiative recombination limits open-circuit voltage. The Shockley-Queisser limit, derived from detailed balance principles assuming blackbody radiation and absorption, caps single-junction efficiency at 30% for a 1.1 eV bandgap under unconcentrated sunlight, rising to 33% at an optimal 1.34 eV bandgap due to better spectral matching, though practical cells achieve 15-25% owing to non-radiative recombination and reflection.[32][33] CST systems concentrate direct beam radiation via mirrors (e.g., parabolic troughs, heliostats, or dishes) onto a receiver, achieving flux densities of 100-1000 suns to heat synthetic oils, molten salts, or air to 300-1000°C. This thermal energy transfers to a heat exchanger, generating steam that drives conventional turbines at efficiencies up to 40%, limited by the Carnot cycle between receiver temperature and ambient sink (e.g., 30% for a 565°C hot side and 25°C cold side). Unlike PV, CST leverages the full solar spectrum for heat but requires direct normal irradiance (DNI > 1800 kWh/m²/year for viability) and incurs optical and parasitic losses from tracking and piping; overall plant efficiencies range 10-20%.[34][35][36] Emerging principles, such as multi-junction cells stacking bandgaps to exceed the single-junction limit (up to 47% theoretically under concentration) or hybrid PV-thermal systems recovering waste heat, build on these foundations but remain niche due to cost and complexity. All conversions obey the first law of thermodynamics, conserving energy but dissipating much as entropy via irreversible processes like blackbody emission and conduction.[37][38]Historical Development
The earliest documented uses of solar energy involved passive techniques, such as the concentration of sunlight with mirrors to ignite fires, dating back to the 7th century B.C. in Greece and China.[39] In the 3rd century B.C., Greeks employed polished bronze shields as burning mirrors for military purposes, while Romans in the 20 A.D. era designed buildings with south-facing windows to capture solar heat for warming interiors.[39] These methods relied on direct thermal harnessing rather than conversion to electricity, laying rudimentary groundwork for later active technologies. The photovoltaic effect, foundational to modern solar cells, was discovered in 1839 by French physicist Alexandre-Edmond Becquerel, who observed that certain materials produced voltage when exposed to light.[39] Practical photovoltaic cells emerged in the late 19th century; in 1883, American inventor Charles Fritts constructed the first selenium-based cell coated with a thin gold layer, achieving 1-2% efficiency but limited by high cost and low output.[40] Solar thermal applications advanced concurrently, with Augustin Mouchot demonstrating a solar-powered steam engine in France during 1861-1864, capable of running small machinery.[41] By 1908, Frank Shuman built a larger solar thermal engine in Egypt using parabolic troughs to generate 50 horsepower, though projects stalled due to cheaper fossil fuels.[39] A breakthrough in photovoltaic technology occurred on April 25, 1954, when researchers Daryl Chapin, Calvin Fuller, and Gerald Pearson at Bell Laboratories developed the first practical silicon solar cell with 6% efficiency, enabling reliable electricity generation from sunlight.[42] This innovation powered the Vanguard 1 satellite launched on March 17, 1958, marking the first space application of photovoltaics and demonstrating durability in vacuum conditions.[42] Terrestrial adoption lagged due to costs exceeding $300 per watt in the 1950s-1960s; efficiencies improved to 10% by 1959 via Hoffman Electronics, but panels remained niche for remote or off-grid uses.[31] Solar thermal systems saw early commercialization in water heating; by 1912, the first commercial solar water heater was installed in California, with over 10,000 units sold by the 1920s before refrigeration Freon competition diminished demand.[39] The 1970s oil crises spurred renewed investment: the U.S. Department of Energy funded research, leading to the 1981 Solar One pilot plant in California, a 10 MW concentrated solar power tower using molten salt for storage.[42] Photovoltaic costs fell from $20 per watt in 1975 to under $5 by 1985 through manufacturing scale-up, though grid parity remained elusive until the 2010s.[42] These developments shifted solar from experimental to viable energy source, driven by material science advances and policy incentives amid fossil fuel volatility.Current Technologies and Efficiency
Crystalline silicon photovoltaic (PV) cells dominate current solar energy conversion, accounting for over 95% of global module production. Monocrystalline silicon modules, produced from single-crystal ingots via the Czochralski process, achieve commercial efficiencies of 20-23%, with premium models like Maxeon's reaching 22.8% as of October 2025.[43] Polycrystalline silicon variants, formed by casting molten silicon into blocks, offer slightly lower efficiencies of 15-20% but lower production costs due to simpler manufacturing.[37] These efficiencies reflect module-level performance under standard test conditions (1000 W/m² irradiance, 25°C cell temperature), though real-world output degrades by 0.5-1% annually from factors like thermal losses and soiling.[44] Thin-film PV technologies, including cadmium telluride (CdTe) and copper indium gallium selenide (CIGS), provide alternatives with commercial module efficiencies of 10-13%, prioritizing lower material use and flexibility for building-integrated applications over peak conversion rates.[37] CdTe modules, led by First Solar, excel in low-light conditions and temperature coefficients but face supply chain constraints for tellurium.[45] Emerging tandem architectures, combining silicon with perovskites, have demonstrated laboratory cell efficiencies exceeding 33% on areas up to 260 cm², as achieved by LONGi in June 2025, though commercial scaling remains limited by stability issues like perovskite degradation under humidity and UV exposure.[46] The National Renewable Energy Laboratory (NREL) tracks confirmed research-cell records, with multi-junction III-V cells reaching 47.6% under concentrated light, but these are unsuitable for widespread terrestrial use due to high costs.[47]| Technology Type | Commercial Module Efficiency (%) | Best Research-Cell Efficiency (%) | Key Limitations |
|---|---|---|---|
| Monocrystalline Si | 20-23 | 26.7 (single-junction Si) | High pure silicon demand |
| Polycrystalline Si | 15-20 | N/A (subset of crystalline) | Lower purity yields |
| CdTe Thin-Film | 18-22 | 22.1 | Toxic materials handling |
| Perovskite Tandem | <5 (emerging) | 33.0+ | Long-term stability |
| III-V Multi-Junction | N/A (concentrated) | 47.6 | Cost-prohibitive |
Recent Developments and Innovations
In 2024 and 2025, tandem solar cells combining perovskite and silicon layers have achieved certified efficiencies exceeding 33%, surpassing single-junction silicon limits through better spectral utilization.[46] [52] LONGi Green Energy reported a 33.9% efficiency for a perovskite-silicon tandem cell in July 2025, verified under standard test conditions, marking a progression from their prior 34.6% record in 2024.[52] [53] Oxford PV demonstrated a commercial-scale tandem module reaching 25% efficiency in August 2025, emphasizing scalability for module production over lab-scale cells.[54] Parallel efforts in all-perovskite tandems yielded over 29% efficiency in monolithic configurations by early 2025, though commercialization lags due to material durability concerns.[55] These gains stem from optimized bandgaps and interface engineering, enabling broader light absorption without excessive recombination losses.[47] Perovskite stability has advanced via protective coatings and additives; Northwestern University researchers tripled operational lifespan in November 2024 using a molecular coating that mitigates degradation from moisture and heat.[56] Spanish teams incorporated unique additives in 2025 to extend panel durability, addressing historical weaknesses that limited field deployment.[57] Machine learning applications have accelerated material screening, reducing voltage losses in p-i-n perovskite cells and aiding scalable manufacturing.[58] NREL's updated efficiency chart through July 2025 confirms hybrid interdigitated back contact cells at 27.81% for silicon-based designs, while tandem architectures push boundaries toward 35% in prototypes.[47] [59] Innovations like fiber-shaped perovskites explore flexible applications, evolving from planar to structured designs for enhanced mechanical resilience.[60] Despite progress, real-world integration requires resolving lead toxicity and long-term reliability, with peer-reviewed studies underscoring the need for causal analysis of degradation mechanisms over optimistic projections.[61]Economic Viability and Market Realities
Solar photovoltaic (PV) module prices have declined sharply, reaching approximately $0.10 to $0.18 per watt in 2024, driven primarily by overcapacity in Chinese manufacturing and economies of scale.[62][63] Installed system costs for utility-scale projects averaged around $1.56 per watt AC in 2023, while residential systems in the United States ranged from $2.50 to $3.30 per watt before incentives.[64][65][66] These reductions have enabled rapid capacity additions, with global solar installations reaching about 2.2 terawatts cumulative by the end of 2024, contributing roughly 7 to 10 percent of worldwide electricity generation.[67][68] However, economic viability is constrained by solar's low capacity factors, typically 15 to 25 percent for PV systems, compared to 50 to 60 percent for coal and over 90 percent for nuclear, necessitating overbuilding and backup generation to achieve reliable output.[69][70] Levelized cost of energy (LCOE) estimates for utility-scale solar averaged $0.043 per kilowatt-hour globally in 2024, but these figures often exclude intermittency-related expenses such as grid upgrades, storage, and firming capacity, which can add 20 to 50 percent or more to effective system costs depending on penetration levels.[71][72][73] In the United States, integrating high solar shares requires $338 to $476 billion in grid modernization by 2030 to manage variability, with additional operational costs from curtailment and negative pricing during peak production.[74] Government subsidies remain critical to deployment, with U.S. federal tax credits under the Inflation Reduction Act supporting over $100 billion in clean energy projects by 2024, including solar-specific incentives that cover 30 to 50 percent of upfront costs.[75] Globally, state-backed financing, particularly in China, has fueled manufacturing dominance but raised concerns over market distortions from subsidized exports and potential dumping.[76] Without such supports, unsubsidized solar struggles to compete in regions with established dispatchable sources, as evidenced by stalled projects amid subsidy phase-outs or policy shifts, such as those under the Trump administration in 2025.[77][78]| Energy Source | Typical Capacity Factor (%) |
|---|---|
| Solar PV | 15-25 |
| Wind | 35 |
| Coal | 50-60 |
| Natural Gas | 50-60 |
| Nuclear | 90+ |
Environmental Impacts and Criticisms
Solar photovoltaic (PV) systems generate electricity without direct emissions during operation, resulting in lifecycle greenhouse gas emissions typically ranging from 20 to 50 grams of CO2-equivalent per kilowatt-hour, substantially lower than coal (around 800-1000 g CO2-eq/kWh) or natural gas (400-500 g CO2-eq/kWh).[83] However, over 80% of these emissions occur during manufacturing, primarily from energy-intensive processes like silicon purification and panel assembly, often reliant on coal-powered facilities in regions such as China.[84] The extraction of raw materials for PV panels, including silicon, silver, copper, and rare earth elements, involves mining operations that cause significant environmental degradation, such as habitat destruction, soil contamination, and water pollution. For instance, silver mining for conductive pastes contributes to biodiversity loss in sensitive ecosystems, while polysilicon production generates hazardous byproducts like silicon tetrachloride, requiring additional energy for mitigation.[85] [86] Critics argue that the scale of demand for these minerals exacerbates global mining pressures, potentially offsetting some climate benefits through increased deforestation and ecosystem fragmentation in mining hotspots.[87] Large-scale solar farms require substantial land areas—approximately 5-10 acres per megawatt—leading to habitat loss and fragmentation that can displace wildlife and alter local biodiversity. Studies indicate that ground-mounted arrays disrupt soil ecosystems and bird migration patterns, with potential for bird mortality from panel collisions or heat islands under arrays.[88] [89] While some managed sites with pollinator-friendly vegetation may support certain species, evidence suggests net negative impacts on threatened fauna in undisturbed habitats, challenging claims of universal biodiversity enhancement.[90] At end-of-life, solar panels pose disposal challenges due to embedded toxic materials like lead, cadmium, and heavy metals, with global recycling rates below 10% as of 2023, leading to landfill leaching risks that contaminate soil and groundwater. Panels typically last 25-30 years, projecting over 78 million tons of PV waste by 2050, yet economic incentives for recycling remain limited, as landfilling is cheaper in many jurisdictions.[91] [92] Energy payback times for modern utility-scale PV systems have shortened to 0.5-1.2 years in high-insolation U.S. locations, reflecting efficiency gains and manufacturing improvements.[93] However, energy return on investment (EROI) calculations face criticism for underestimating system-level costs, including storage and backup generation needed for intermittency, which can reduce effective EROI below 10:1 in high-penetration scenarios, questioning long-term sustainability without fossil fuel crutches.[94] [95] Detractors, including energy analysts, contend that optimistic module-only EROI figures ignore these full-system demands, potentially inflating solar's viability in energy-constrained grids.[96]Comparisons to Alternative Energy Sources
Solar photovoltaic (PV) systems exhibit a levelized cost of energy (LCOE) that is competitive with onshore wind but higher than unsubsidized hydro in many regions, with global weighted averages for utility-scale solar PV falling to approximately $0.049/kWh in 2024, compared to $0.033/kWh for onshore wind and $0.061/kWh for geothermal.[97] Nuclear power's LCOE remains elevated at $0.141-0.221/kWh due to high capital costs and long construction timelines, though it provides dispatchable baseload power without intermittency penalties.[98] These figures, derived from analyses like Lazard's, often exclude system-level integration costs such as grid upgrades and storage, which disproportionately affect variable renewables like solar; for instance, adding battery storage to solar can increase effective costs by 50-100% or more for firm capacity.[99] [100]| Energy Source | Approximate LCOE (2024, USD/MWh, unsubsidized) | Key Notes |
|---|---|---|
| Solar PV (utility-scale) | 24-96 | Declining capital costs, but intermittency requires backups.[98] |
| Onshore Wind | 24-75 | Complementary to solar but still variable.[98] |
| Hydro | 40-100 (varies by site) | Site-dependent; low operational costs but limited scalability.[73] |
| Geothermal | 60-120 | Baseload-capable but geographically constrained.[97] |
| Nuclear | 141-221 | High upfront but low fuel and near-zero marginal costs.[98] |
Geography
Settlements and Locations Named Solar
Solar is a populated place in the Northern Province of Sierra Leone, situated at coordinates 8°42′17″ N, 12°55′00″ W.[114] In Guatemala, El Solar is classified as a locality in the municipality of San José Pinula, at approximately 14°32′ N, 90°24′ W.[115] The Philippines features Solar Homes Subdivision, a section of a populated place in the City of Dasmariñas, Cavite, at about 110 meters elevation.[116] Mexico has Colonia del Solar, another section of a populated place in Chihuahua state, located at roughly 31°41′ N, 106°23′ W.[117] These minor locations, documented in geographical databases, represent the primary known settlements or sub-divisions bearing the name "Solar," with no major cities or towns identified by this designation worldwide.Music and Entertainment
Notable Musical Works
"Solar" is a jazz standard composed by guitarist Chuck Wayne in 1946, initially titled "Sonny" and first documented in a jam session recording.[118] It gained prominence through Miles Davis's 1954 recording for Prestige Records, where Davis copyrighted an altered version under his name in 1963, sparking persistent disputes over authorship among jazz insiders who attribute it to Wayne.[119] [120] The piece features a 12-bar blues structure with distinctive harmonic substitutions and has been interpreted by artists including Bill Evans, whose 1963 trio version emphasized its lyrical potential.[121] In contemporary classical music, "Solar" (1993) by Finnish composer Kaija Saariaho employs an ensemble with electronics to evoke a radiant harmonic core that repeatedly resolves amid spectral textures, lasting approximately 18 minutes.[122] [123] Saariaho described it as projecting an unchanging sonic image that influences surrounding elements, premiered by the Avanti Chamber Orchestra.[124] "Solar Fire" (1973) is the fourth studio album by Manfred Mann's Earth Band, blending progressive rock with astronomical themes inspired by Gustav Holst's The Planets, including tracks like "Father of Day, Father of Night" and the title instrumental.[125] It reached number 96 on the Billboard 200, maintaining chart presence for 15 weeks.[126] In popular music, "Solar Power," the lead single from Lorde's 2021 album of the same name, critiques modern escapism through upbeat synth-pop, released on June 11 and peaking within top-10 charts in multiple countries.[127]Artists and Performers
Solar (born Kim Yong-sun on February 21, 1991) is a South Korean singer and actress who serves as the leader and main vocalist of the K-pop group MAMAMOO, debuting with the group under RBW Entertainment on June 19, 2014.[128] She has pursued solo activities since 2020, releasing albums such as Faces of Love (2023) and performing in concerts like the two-day "Solaris" series held on October 11 and 12, 2025, in Seoul.[128] In 2021, Solar received the Best Entertainer Award at the KBS Entertainment Awards for her appearances on shows like New Singer and Boss in the Mirror.[129] CJ Solar is an American country music artist recognized for blending rock influences with traditional country elements, having opened for prominent acts including Lynyrd Skynyrd, 38 Special, and Gary Allan as of 2023.[130] Magnus Birgersson, performing under the alias Solar Fields, is a Swedish composer and sound designer specializing in ambient and electronic music, with notable works including the soundtrack for the video game Mirror's Edge (2008) and albums like Mirror's Edge OST.[131]Companies
Energy and Technology Firms
Chinese firms dominate the global solar photovoltaic (PV) module manufacturing market, accounting for approximately 86% of worldwide production as of 2025, driven by economies of scale, government subsidies, and integrated supply chains for polysilicon and wafers.[132] JinkoSolar, headquartered in Shanghai, led global module shipments in 2024 with 90.6 gigawatts (GW), emphasizing high-efficiency n-type TOPCon modules that achieve conversion efficiencies exceeding 22%.[133] JA Solar followed closely with 89.8 GW shipped, focusing on perovskite-silicon tandem cell prototypes that promise efficiencies above 30% in pilot production.[133] LONGi Green Energy, the largest by projected 2025 shipments at over 45 GW (nearly 20% market share), pioneered monocrystalline silicon advancements, including HPBC (hybrid passivated back contact) cells reaching 25.4% efficiency in lab settings.[134]| Manufacturer | 2024 Shipments (GW) | Key Technology Focus |
|---|---|---|
| JinkoSolar | 90.6 | n-type TOPCon modules |
| JA Solar | 89.8 | Perovskite tandems |
| LONGi | ~80 (est.) | Monocrystalline HPBC |
| Trina Solar | ~70 (est.) | Bifacial n-type |
| Canadian Solar | ~50 (est.) | High-power modules |