Search results
Results from the WOW.Com Content Network
Electricity generation is the process of generating electric power from sources of primary energy. For utilities in the electric power industry , it is the stage prior to its delivery ( transmission , distribution , etc.) to end users or its storage , using for example, the pumped-storage method.
The energy source harnessed to turn the generator varies widely. Most power stations in the world burn fossil fuels such as coal, oil, and natural gas to generate electricity. Cleaner sources include nuclear power, and increasingly use renewables such as the sun, wind, waves and running water.
The electric field sends the electron to the p-type material, and the hole to the n-type material. If an external current path is provided, electrical energy will be available to do work. The electron flow provides the current, and the cell's electric field creates the voltage. With both current and voltage the silicon cell has power.
A schematic representation of long distance electric power transmission. From left to right: G=generator, U=step-up transformer, V=voltage at beginning of transmission line, Pt=power entering transmission line, I=current in wires, R=total resistance in wires, Pw=power lost in transmission line, Pe=power reaching the end of the transmission line, D=step-down transformer, C=consumers.
The element's voltages increase, but so does their output resistance. The maximum power transfer theorem dictates that maximum power is delivered to a load when the source and load resistances are identically matched. For low impedance loads near zero ohms, as the generator resistance rises the power delivered to the load decreases.
Non-ideal voltage source model (left) and non-ideal current source model (right) A generator in electrical circuit theory is one of two ideal elements: an ideal voltage source, or an ideal current source. [1] These are two of the fundamental elements in circuit theory. Real electrical generators are most commonly modelled as a non-ideal source ...
Figure 1: An ideal current source, I, driving a resistor, R, and creating a voltage V. A current source is an electronic circuit that delivers or absorbs an electric current which is independent of the voltage across it. A current source is the dual of a voltage source. The term current sink is sometimes used for sources fed from a negative ...
Illustration of the "reference directions" of the current (), voltage (), and power () variables used in the passive sign convention.If positive current is defined as flowing into the device terminal which is defined to be positive voltage, then positive power (big arrow) given by the equation = represents electric power flowing into the device, and negative power represents power flowing out.