461 articles
Current-voltage hysteresis
Current-voltage hysteresis is the discrepancy between forward and reverse current-voltage scans of a solar cell, characteristic of metal halide perovskite cells, caused mainly by ion migration and complicating efficiency measurement.
CZTS solar cell
A CZTS solar cell is a thin-film photovoltaic device with a kesterite copper zinc tin sulfide absorber built from earth-abundant, non-toxic elements in the CIGS architecture.
d.light
d.light is an off-grid solar energy company founded by Sam Goldman and Ned Tozun at Stanford in 2007, selling solar lanterns and home systems on pay-as-you-go plans in Africa and India.
Darien Solar
Darien Solar, formally the Darien Solar Energy Center, is a 250 MW utility-scale solar power plant in southern Wisconsin, owned mainly by We Energies and online since March 2025.
Dawn Harvest Solar
Dawn Harvest Solar, formally the Dawn Harvest Solar Energy Center, is a 150 MW solar and battery facility in Rock County, Wisconsin, being acquired by We Energies and other utilities.
DC disconnect switch
A DC disconnect switch, also called a DC isolator or PV disconnect, is a manually operated switch installed between a PV array and inverter for safe isolation.
Defect tolerance
Defect tolerance is a concept in semiconductor physics describing materials that stay efficient despite high defect densities, best known in lead-halide perovskites, which made low-cost solution-processed solar cells possible.
Delilah I Solar Energy Center
Delilah I Solar Energy Center is a 300-megawatt utility-scale solar power plant in Northeast Texas that sells its output to Honda and Tesla under 15-year contracts.
Diamond wire sawing
Diamond wire sawing is a wafer-slicing process in which steel wire coated with fixed diamond abrasive cuts hard, brittle materials such as silicon, silicon carbide, and sapphire into wafers.
Dinawan Energy Hub
The Dinawan Energy Hub is a proposed hybrid wind, solar, and battery project of up to 2 GW in the Riverina region of New South Wales, developed by Spark Renewables.
Dion-Jacobson phase
The Dion-Jacobson phase is a family of layered perovskite compounds, with formulas like A′An−1BnO3n+1, where single interlayer cations bond both adjacent inorganic slabs, unlike the Ruddlesden-Popper phase.
Direct normal irradiance
Direct normal irradiance (DNI), also called beam radiation, is the rate at which direct sunlight reaches a surface perpendicular to the Sun's beam, measured in watts per square meter.
Direct steam generation
Direct steam generation (DSG) is a concentrating solar power technology that produces steam directly in collector receiver tubes, removing the oil loop and heat exchangers for higher efficiency and simpler plants.
Dopant-free hole transport
Dopant-free hole transport is the design of hole transport materials for perovskite solar cells that are intrinsically conductive without chemical dopants, improving stability and cutting fabrication cost; top efficiencies exceed 25%.
DPP-based small-molecule donors
DPP-based small-molecule donors are conjugated organic molecules built around the diketopyrrolopyrrole (DPP) chromophore that act as electron donors in organic solar cells, reaching power conversion efficiencies up to 12%.
Duane Arnold Solar
Duane Arnold Solar, later renamed Pleasant Creek Solar, is a 200 MW solar farm with 75 MW of battery storage in Linn County, Iowa, completed in 2024.
Duck curve
The duck curve is the graph of a power grid's daily net load after solar generation is subtracted, sagging at midday and climbing steeply in the evening.
Dye-sensitized solar cell
A dye-sensitized solar cell, also called a Grätzel cell, is a photovoltaic device where dye on titanium dioxide absorbs light; invented at EPFL in 1991, it excels indoors.
Dyson sphere
A Dyson sphere, also called a Dyson shell or Stapledon sphere, is a hypothetical megastructure around a star collecting its energy, proposed by Freeman Dyson in 1960.
Electrically conductive adhesive (photovoltaics)
An electrically conductive adhesive (ECA) in photovoltaics is a polymer filled with conductive particles that bonds solar cells to copper ribbon while carrying current across the joint.
Electron transport layer
An electron transport layer is an n-type semiconductor film in a solar cell that extracts photo-generated electrons to the electrode and blocks holes, used chiefly in perovskite solar cells.
Emitter wrap through solar cell
The emitter wrap through (EWT) solar cell is a crystalline silicon back-contact cell whose emitter connects to rear contacts through laser-drilled vias, first published by Sandia researchers in 1993.
Enphase Energy
Enphase Energy is a Fremont, California energy technology company founded in 2006 by Raghu Belur and Martin Fornage, which has shipped about 87.8 million microinverters to systems in over 165 countries.
Eurus Energy
Eurus Energy Holdings Corporation is a Japanese wind and solar power developer, owned by Toyota Tsusho since 2022 and Japan's largest, with about 5.2 GW across 18 countries.
Evacuated tube collector
An evacuated tube collector is a solar thermal collector that heats water using glass tubes held under vacuum to retain heat, reaching up to 400 °C.
First Solar
First Solar, Inc. is an American photovoltaic module manufacturer headquartered in Phoenix, Arizona. Founded in 1999, it is the only US-headquartered company among the world's largest solar manufacturers, making cadmium telluride thin film modules.
Flat Glass Group
Flat Glass Group (福莱特) is a Chinese glass manufacturer founded in 1998 and headquartered in Jiaxing, Zhejiang, one of the world's largest producers of photovoltaic glass for solar modules.
Flat-plate collector
A flat-plate collector is a non-concentrating solar thermal collector in which a flat, glazed absorber plate heats a circulating fluid, used for domestic water heating and space heating.
Flexible perovskite solar cell
A flexible perovskite solar cell is a thin-film photovoltaic device made on bendable substrates such as plastic, metal foil, or ultrathin glass, with single-junction efficiencies now above 23%.
Flexible perovskite solar modules
Flexible perovskite solar modules are photovoltaic modules that integrate multiple perovskite sub-cells on bendable plastic or metal foil substrates, offering high efficiency, low weight, and roll-to-roll manufacturing compatibility.