Solar Energy terms starting with D

67 terms

Day-night average noise level Twenty-four-hour average noise level, obtained after the addition of a 10-dB penalty for environmental noise occurring from 10 p.m. to 7 a.m.
Daytime mean rural background level Daytime (7 a.m. to 10 p.m.) average sound level in the rural environment, from all sources other than a particular noise that is of interest.
DC See Direct current
Debris flow A mixture of water-saturated rock debris that flows downslope under the force of gravity (also called lahar or mudflow).
Debris flow fans Alluvial fans prone to debris flows; a mixture of water and debris, such as mudslides, mudflows, or debris avalanches.
Decibel (dB) A standard unit for measuring the loudness or intensity of sound. In general, a sound doubles in loudness with every increase of 10 decibels.
Decibel, A-weighted (dBA) A measurement of sound approximating the sensitivity of the human ear and used to characterize the intensity or loudness of a sound.
Deciduous Plants that shed their leaves annually. Not evergreen.
Decommissioning The process of removing a power plant, apparatus, equipment, building, or facility from operation.
Deep-cycle battery A battery with large plates that can withstand many discharges to a low state of charge.
Delta The relationship between an option's price and the price of the underlying stock or futures contract is called its delta.
Demand-side management Specific actions taken by utility companies, their regulators, and other entities to induce, influence, or compel consumers to reduce their energy…
Demographic Related to the vital statistics of human populations (size, density, growth, distribution, etc.) and the effect of these on social and economic conditions.
Depletion Net loss of water through consumption, export, and other uses to a given area, river system, or basin.
Deposit An amount of money paid to the court. Hennepin County Housing Court can only accept cash and certified checks; personal checks, third-party checks, and…
Desert Arid region receiving less than 10 inches of precipitation annually.
Desert bench A relatively flat terrace elevated above the surface of a desert alluvial feature, such as an ephemeral stream or wash.
Desert dune A wind-created ridge or mound of sand that is found in deserts or near oceans and lakes.
Desert floor The land surface in a desert valley.
Desert focal bird species Bird species whose requirements define spatial attributes, habitat characteristics, and management regimes representative of a healthy desert system.
Desert pavement A surface layer of closely packed, loosely cemented pebbles. See also Pediment
Desert riparian habitat Habitats characterized as dense groves of low shrublike trees, or tall shrubs to woodlands of small to medium-sized trees.
Desert scrub The desert scrub community is characterized by plants adapted to seasonally dry climate.
Desert varnish The thin red to black coating found on exposed rock surfaces in arid regions. Varnish is composed of clay minerals, oxides, and hydroxides of manganese…
Desert wash A usually dry desert streambed that flows only after periods of heavy rain.
Desiccation The process of removing moisture; involves evaporation.
Design basis The set of conditions, dimensions, needs, and requirements used to design a solar energy facility.
Design features Measures or procedures incorporated into the proposed action or alternatives which could avoid or reduce adverse impacts.
Designated Roads and Trails Specific roads and trails identified by the agencies where some type of motorized vehicle use is appropriate and allowed, either seasonally or yearlong.
Detritus Loose natural materials, such as rock fragments or organic particles, that result directly from disintegration of rocks or organisms.
Dewatering The separation of free water from the solids portion of spent mash, sludge, or whole stillage by screening, centrifuging, filter pressing, or other means.
Diagnostic An item that is indicative of a particular time and/or cultural group.
Differential compaction May occur over a large area when the compaction of soil or deeper sediments occurs at different rates and degrees.
Diorite A coarse-grained intrusive (or plutonic) igneous rock, less mafic than gabbro, but more mafic than granite and granodiorite; the plutonic equivalent of…
Dip The angle that a planar geologic surface, for example, a fault, is inclined from the horizontal.
Direct current (DC) A steady current that flows in one direction only. The current from batteries is an example of direct current.
Direct effects Effects on the environment which occur at the same time and place as the initial cause or action.
Direct impacts Impacts occurring at the place of origin and at the time of the proposed activity.
Direct Normal Insolation (DNI) Sunlight that directly strikes a surface. DNI does not include refracted sunlight that strikes clouds, dust, or the ground first.
Directional drilling The practice of drilling non-vertical wells. Also called slant drilling.
Discharge (DIS-charj) In medicine, a fluid that comes out of the body. Discharge can be normal or a sign of disease.
Dish engine The dish engine is a concentrating solar power (CSP) technology that produces electricity, typically in the range of 3 to 25 kilowatts, by using a…
Dish engine system See Dish engine
Dish engine technologies See Dish engine
Dispatchable power (dispatchability) The ability of a power-producing facility to provide required amounts of power (at or below the facility's nameplate rating) on demand of the grid…
Disposal A term used in some countries, including the U.S., to mean that an application has been abandoned, denied (rejected) or allowed (granted).
Distance zones A subdivision of the landscape as viewed from an observer position. The BLM defined zones include foreground, middleground, background, and seldom seen.
Distributed Generation A term used by the power industry to describe localized or on-site power generation.
Disturbance (land) See Land disturbance
Diversion The process of removing some minor criminal, traffic or juvenile cases from the full judicial process, on the condition that the accused undergo some sort…
DNI See Direct Normal Insolation
Dolomite A magnesium-rich carbonate sedimentary rock. Also, a magnesium-rich carbonate mineral (CaMgCO3).
Dome, volcanic Rounded, steep-sided mounds built by very viscous magma, usually either dacite or rhyolite.
Domestic solid waste Solid wastes of the type routinely generated by households.
Domestic water use Water used for household purposes such as drinking; food preparation; bathing; washing clothes, dishes, and dogs; flushing toilets; and watering lawns and…
Down-dropped basin See Graben
Drawdown Lowering a lake level for a specific purpose.
Drill An oblong tool made of flaked stone used in drilling holes in wood, leather or hides.
Drop structure An in-stream structure of various materials designed to reduce the energy and force of stream flow.
Dry closed-loop cooling See Dry cooling system
Dry cooling See Dry cooling system
Dry cooling system Also known as dry closed-loop cooling; a technology for rejecting heat from the steam condensate of a thermoelectric plant.
Dry lake An ephemeral lake of an arid or semiarid region, typically found at low elevation points in desert valleys.
Dry wash A natural drainage channel that is typically dry, but conveys water following significant rainfall events and is subject to rapid flow during flash…
Dune Mounds of unconsolidated sand grains shaped by wind. Often temporary and nonstationary.
Dunnage Supports for air conditioning and other equipment above the roof of a building.
Duripan A subsurface soil horizon cemented by silica (usually derived from a volcanic source such as ash).