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Duty cycle. The duty cycle is defined as the ratio between the pulse duration, or pulse width ( ) and the period ( ) of a rectangular waveform. Spectrum in relation to duty cycle. A duty cycle or power cycle is the fraction of one period in which a signal or system is active. [1] [2] [3] Duty cycle is commonly expressed as a percentage or a ratio.
Solar-cell efficiency is the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity by the solar cell . The efficiency of the solar cells used in a photovoltaic system, in combination with latitude and climate, determines the annual energy output of the system. For example, a solar panel with 20% ...
The runoff curve number (also called a curve number or simply CN) is an empirical parameter used in hydrology for predicting direct runoff or infiltration from rainfall excess. [ 1] The curve number method was developed by the USDA Natural Resources Conservation Service, which was formerly called the Soil Conservation Service or SCS — the ...
Basal metabolic rate. Basal metabolic rate ( BMR) is the rate of energy expenditure per unit time by endothermic animals at rest. [ 1] It is reported in energy units per unit time ranging from watt (joule/second) to ml O 2 /min or joule per hour per kg body mass J/ (h·kg). Proper measurement requires a strict set of criteria to be met.
The net capacity factor is the unitless ratio of actual electrical energy output over a given period of time to the theoretical maximum electrical energy output over that period. [ 1] The theoretical maximum energy output of a given installation is defined as that due to its continuous operation at full nameplate capacity over the relevant period.
Fuel economy in aircraft. Between 1950 and 2018, efficiency per passenger grew from 0.4 to 8.2 RPK per kg of CO₂. [1] The fuel economy in aircraft is the measure of the transport energy efficiency of aircraft . Fuel efficiency is increased with better aerodynamics and by reducing weight, and with improved engine brake-specific fuel ...
The energy efficiency in transport is the useful travelled distance, of passengers, goods or any type of load; divided by the total energy put into the transport propulsion means. The energy input might be rendered in several different types depending on the type of propulsion, and normally such energy is presented in liquid fuels, electrical ...
The levelized cost of electricity (LCOE) is a metric that attempts to compare the costs of different methods of electricity generation consistently. Though LCOE is often presented as the minimum constant price at which electricity must be sold to break even over the lifetime of the project, such a cost analysis requires assumptions about the value of various non-financial costs (environmental ...