Content – Energy sources
Generation of electrical power is mainly done by use of generators (electromagnetic induction) that converts mechanical energy into electricity often driven by a heat engine or a hydro or wind turbine.
Energy generation – Methods
Electromagnetic induction – Kinetic energy is transformed by use of an electrical generator, dynamo or alternator. This is by far the most common method used for generating electricity.
Photovoltaic energy generation – Light is transformed into electricity by use of solar cells.
Static electricity – Transformation occurs when a material`s imbalance in charge is discarged. The charge is created when two materials are brought together and then separated and one of the materials has high resistanse to electrical current. Static electricity comes to pratical use mainly in connection with photocopying, filtering, spray painting, X-ray tubes and sterilization of food in addition various laboratory appliances.
Electrochemical energy generation – Transformation of chemical energy into electricity in batteries or fuel cells
Thermoelectrical energy generation – Utilise temperature differentials within a material for direct conversion into electricity. Thermoelectric Generators are primarily used as remote power generators outside the electrical grid utilising “waste” heat. Materials used for thermoelectric energy generation needs to have high electrical conductivity and at the same time low thermal conductivity such that a high temperature difference may be maintained between one side of the material to the other and thereby allowing a high electrical potential (voltage). The measurement of electron flow across a material as a function of a temperature difference is given by the Seebeck coefficient(S). It’s efficiency to produce thermoelectric power is governed by its “figure of merit” (zT).
Piezoelectric energy generation – Electrical charge accummulating in certain materials from mechanical stress. Materials would typically be crystals, some ceramics and bone. Applications for piezoelectric elements are numerous; such as ignition of gas cigarette lighters, gas stoves and gas burners, it is being used in a vatiety of sound sensors and actuators.
Nuclear transformation. – Creation and acceleration of charged particles. Only small scale and laboratory use.