glossery of electrical terms

Glossery of electrical terms.

Alternating current (AC) electric current whichalternates its direction of flow. Frequency is measured in hertz (60 cylcles per second in N. America)	Amp (A) is a measure of electric current; one A of current represents one coulomb of electrical charge moving past a specific point in one second (1 C/s = 1 A).
Amp-hours (Ah) is used to express the storage capacity of a battery (that is, 100 Ah battery can provide 1 A over a period of 100 hours or 100 A over a period of 1 hour).	Anemometer is a device used to measure wind speed.
Annual average wind speed (AWS) is the average of all instantaneous wind speeds for a location over the course of a year.	Annual energy output (AEO) is the total energy produced by a wind turbine over the course of a year.
Battery Autonomy is the length of time which a battery bank can support a specific load without overcharging. A value used to measure battery reserve capacity and system reliability.	Battery bank is a group of deep cycle batteries wired in series or parallel, to be a certain voltage eg: 12,24,48 or 96volts DC. A battery bank stores the energy produced by your wind turbine for later usage.
Blocking diode an eletrical device that allows current to flow in only one direction.	Charge controller ( regulator ) an electronic device which regulates the amount of charge flowing from a source to a battery. Used to prevent battery overcharging, sometimes with load control / diversion as well.
Current is the rate at which electricity flows through a conductor; measured in amps (A).	Cut-in wind speed is the lowest wind speed (at hub height) at which the turbine starts to produce power.
Direct current ( DC ) electric current which flows in only one direction in a wire. Our turbines and batteries are DC.	Depth of discharge ( DOD ) the percentage of a battery's full capacity which has been removed, expressed as a percentage.
Electrolyte the acid mix in flooded lead acid batteries.	Equalization the process of balancing the state of charge in all the cells that form a battery bank. This is done to remove sulphates from battery plates and restore capacity
Free standing tower is a tower that does not use external supports, such as guy wires.	Grid term used when referring to standard electrical power from your utility company.
Guy anchor is a foundation designed for guy wire connection.	Guy cable is a cable or wire used as a tension support between a guy anchor and a tower.
Guyed tower is a tower that uses external guy supports.	Hub is the fixture for attaching the blades or blade assembly of a HAWT to the rotor shaft.
Hub height is the height of the centre of the wind turbine rotor above the ground.	Hybrid System term used to describe an alternative energy system which uses multible charging sourse along with solar electric modules such as wind, micro hydro generators.
Inverter an electronic device which converts DC power to AC power so that standard AC appliances can be operated from a battery power.	Load any device connected to an electric circuit which consumes power. eg: appliances, pumps, lights etc.
Maximum power (wind turbines) is the highest sustained level of net electrical power delivered by a wind turbine in normal operation (approximately the same as Rated Power).	Mean wind speed is the statistical mean of the instantaneous value of the wind speed averaged over a given time period which can vary from a few seconds to many years.
Modified sine wave output from invertorsan output waveform of inverters which in approximates standard utility output with a stepped not smooth wave.	Open circuit voltage the voltage produced by a single module in standard isolation conditions with no loads.
Parellel connection / circuit Parellel connections attch positive terminals of modules or batteries together, so voltage remains the same as that of a single module, while the extra current is added.	Power is the expression of the rate of doing work. It is usually measured in watts (W) or kilowatts (kW).
Power curve is a graph that depicts the power output of a wind turbine as a function of wind speed.	Power output is the amount of power produced by a wind turbine at a given speed.
Rated power is the power produced by a wind turbine at the rated wind speed (approximately the same as Maximum Power).	Rated wind speed is the specified wind speed at which a wind turbine's rated power is achieved.
Rayleigh wind speed distribution is a statistical curve whose shape approximates the actual shape of a wind speed distribution curve. It is used as a standardized distribution curve to estimate the energy production performance of a wind turbine.	Rotor is the set of blades of the wind turbine including the hub.
Rotor speed is the rate of rotation of a wind turbine rotor about its axis.	Series connections/circuit Series connections put module or batteries in a string so that current flows from positive to negative through eacg component. The current in series wiring remains the same as that of a single module, while the voltage is added.
Swept area is the area through which the rotor blades rotate. It is the area of the disk formed by the blade rotation.	Sine wave output from inverters is an output waveform or cycling of AC power, which matches the waveform of standard utility power.
State of charge the amount of charge left in a battery stated as a percentage of the total battery power.	Sulphation the growth of lead sulphate crystals on batteryt plates which inhibit the proper operation of a battery. Caused by age or being left in a discharge state for an extented period of time.
Tower is the structure of a wind energy system that supports the rotor and power train, etc., above the ground.	Voltage is a measure of the electric potential difference between two points; usually expressed as volts (V).
Watts is the unit to measure the rate at which work is done (power) or energy is consumed; usually expressed as Watts (W) or kilowatts (kW). Note that W = V x A.	Watt hours ( WHr ) the amount of power consumed over a period of time. An appliance drawing 100 watts which runs for 5 hours per day, will consume 500WHrs per day.