A Vertical Axis Wind Turbine design from the 1920s and 1930s by F.M. Darrieus, a French wind turbine designer.
Search the Web for DarrieusThe number of consecutive days the stand-alone system will meet a defined load without solar energy input. This term is related to system availability.
Search the Web for Days Of StorageAgreement in which a certain amount of foreign debt is canceled in exchange for local currency investments that will improve natural resource management or protect certain areas in the debtor country from harmful development.
Search the Web for Debt-for-nature SwapA Deep Cycle Battery is a battery that is capable of been discharged to nearly completely empty without long term negative effects on the life of the battery and its storage capacity.
The number of consecutive days the stand-alone system will meet a defined load without solar energy input. This term is related to system availability.
Search the Web for Deep DischargeMechanisms to manage the demand from customers in response to supply conditions.
Search the Web for Demand ResponseRemoval of nitrate and nitrate product from water to produce a quality that answeres common water standards.
Search the Web for DenitrificationThe tendency of a population's growth rate to depend on its size, with an increase in population density corresponding to a decrease in growth. This self-regulating dynamic helps prevent extinction.
Search the Web for Density DependenceThe month having the combination of insolation and load that requires the maximum energy from the photovoltaic array.
Search the Web for Design MonthThe dew point is the temperature to which a given parcel of humid air must be cooled, at constant barometric pressure, for water vapor to condense into water. The condensed water is called dew. The dew point is a saturation temperature.
The dew point is associated with relative humidity. A high relative humidity indicates that the dew point is closer to the current air temperature. Relative humidity of 100% indicates the dew point is equal to the current temperature and the air is maximally saturated with water. When the dew point remains constant and temperature increases, relative humidity will decrease. Search the Web for Dew PointA pesticide used on citrus fruits.
Search the Web for DicofolSunlight falling directly upon a collector. Opposite of diffuse insolation.
Search the Web for Direct InsolationWater that flows from the ground surface directly into streams, rivers, and lakes.
Search the Web for Direct Run-offAir pollutants dropped by prevailing winds.
Search the Web for Dirty FalloutDispatchability is the ability of a power plant to be turned on quickly to a desired level of output. Wind power plants are not dispatchable.
Search the Web for DispatchabilityA Dispersion Trench is a method by which effluent after processing is distributed back into the environment in a way which reduces environmental impact. They often positioned so that the effluent is distributed by a grid of trench pipes into the soil directly; the aim being that the effluent never gets to the surface.
DERs. A variety of small, modular power-generating technologies that can be combined with energy management and storage systems and used to improve the operation of the electricity delivery system, whether or not those technologies are connected to an electricity grid.
Search the Web for Distributed Energy ResourcesThe difference between maximum and minimum temperature over a period of 24 hours.
Search the Web for Diurnal Temperature RangeA unit used to measure the abundance of ozone in the atmosphere; one Dobson unit is the equivalent of 2.69 x 1016 molecules of ozone/cm2.
Search the Web for Dobson UnitA traditional window style with two glass-holding frames that slide past each other vertically.
Search the Web for Double-hung WindowsDowncycling is the recycling of a material into a material of lesser quality. For example, when plastics are recycled they are turned into a lower grade quality plastic.
Search the Web for DowncyclingThe process of accumulation and sinking of warm surface waters along a coastline. A change of air flow of the atmosphere can result in the sinking or downwelling of warm surface water. The resulting reduced nutrient supply near the surface affects the ocean productivity and meteorological conditions of the coastal regions in the downwelling area.
Search the Web for DownwellingEmissions of sulphur and nitrogen oxides that, in the absence of water in the atmosphere (i.e., rain), settle to the ground as particulate matter.
Search the Web for Dry Deposition(water management) Accumulation of salts in soils, soil water and ground water; may be natural or induced by land clearing
Search the Web for Dryland SalinityDryland systems are ecosystems characterised by a lack of water. They include cultivated lands, scrublands, shrublands, grasslands, savannas, semi-deserts and true deserts.
Search the Web for Dryland SystemsA device to which wind generator power flows when the system batteries are too full to accept more power, usually an electric heating element. This diversion is performed by a Shunt Regulator, and allows a Load to be kept on the Alternator or Generator.
Search the Web for Dump LoadAcidic bodies of water that contain many plants but few fish, due to the presence of great amounts of organic matter.
Search the Web for Dystrophic Lakes