전문 용어(English-D)


Days of storage The number of days that a stand-alone system will power a specified load without solar energy input. A measure of system autonomy.
DC to DC converter Electronic circuit to convert DC voltages such as PV module voltages into other levels such as load voltage. Can be part of a maximum power point tracker (MPPT).
Dealer A retailer of PV products and/or PV systems.
Deep cycle battery A battery designed to regularly discharge 80% of its capacity before recharging.
Deep discharge Discharging a battery by more than 80% of its full charge.
Depth of discharge (DOD) The amount of energy withdrawn from a battery or cell expressed as a percentage of its rated capacity.
Design month The month in which the combination of insolation and load requires the maximum energy from the array.
Developer segment Segmentation of developer – Utility, Commercial, Government, Residential.
Diffuse insolation Incident sunlight received indirectly because of scattering due to clouds, fog, particulates, or other obstructions in the atmosphere. The opposite of direct insolation.
Diffuse radiation Radiation received from the sun after reflection and scattering by the clouds, fog, haze, dust or other substances in the atmosphere, and the ground.
Diode Electronic device that allows current flow only in one direction.
Direct beam radiation Radiation received by direct sunlight. Measured by a pyrheliometer with a solar aperture of 5.7
Direct current (DC) Electrical current that flows only in one direction, although it may vary in magnitude. Contrasts with alternating current.
Direct insolation Sunlight falling directly upon a collector. Opposite of diffuse insolation.
Direct radiation Light that has traveled in a straight path from the sun (also referred to as beam radiation). An object in the path of direct radiation casts a shadow on a clear day.
Discharge Withdrawal of electrical energy from a battery.
Discharge factor A number equivalent to the time in hours during which a battery is discharged at constant current. Usually expressed as a percentage of the total battery capacity, i.e., C/5 indicates a discharge factor of 5 hours.
Discharge rate A measure of the current withdrawn from a battery over time, expressed as a percentage of battery capacity. A C/5 discharge rate indicates a current of one-fifth of the rated capacity of the battery.
Disconnect Switch used to connect or disconnect components in a PV system.
Dispatchability The ability of a generating unit or other source of electric power to vary output.
Dispatchable power Energy output that can be planned on and typically provides a continuous power output. Solar power and wind power is not dispatchable without some other power or storage mechanism. Hydrocarbon-based power plants or nuclear plants are dispatchable.
Distributed systems Systems that are installed at or near the location where the electricity is used, as opposed to central systems that supply electricity to grids. A residential photovoltaic system is a distributed system.
Distributor A wholesaler of PV products.
Downstream Distribution, system integration and installation at the site of the end-se for electricity generation.
Downtime Time when the PV system cannot provide power to the load, expressed either in hours per year or as a percentage.
Dry cell battery A battery that uses a solid paste for an electrolyte.
DS or DSS Directional solidification or directional solidification systems.
DSSC Dye-sensitized solar cell.
Duty cycle The ratio of active to total time, used to describe the operating regime of loads in PV systems.
Duty rating The amount of time an inverter can operate at full rated power without overheating.