Going back to the basics- electricity supply value chain
We make a lot of assumptions in life until we are faced with certain situations before the realization that we do not even have a good understanding or knowledge of very basic things.
Many lawyers and advisers on electric power deals might understand the law and have a pretty good knowledge of the legal regime related to the electric power sector; however, they may not understand some of the basics of electric power generation, transmission and distribution. They may also not know this until faced with real life situations. Consequently, this week, we provide an insight into electric power generation, transmission and distribution.
Generation
The process of generating electric power, transmitting same and then distributing to millions of commercial, industrial and residential consumers is, in fact, an incredibly complex process and a breath-taking accomplishment. Electric power can be generated in different ways.
Most power plants (Power plants are similar to generators but are themselves very large generators) however, use analogous equipment whereby generators are driven by superheated steam. These power plants burn oil, natural gas or coal to produce this superheated steam. Nuclear generators, which are not commonplace in this part of the world, use nuclear fission to turn water into steam. Hydroelectricity which is relatively common in Nigeria uses water in the production of electricity.
Power plants require fuel to function; just the way an aircraft or a motor vehicle requires aviation fuel or premium motor spirit/automotive gas oil to fire its engine. Apart from renewable fuel sources such as wind and sunlight, natural gas is regarded as the fuel of the future because of its advanced thermal efficiency, clean combustion characteristics and the significant volume of natural gas available worldwide (Peter Roberts). Natural gas is extracted from underground wells and transported to customers through pipelines or shipped in cryogenic tanks as liquefied natural gas and then re-gasified at its final destination.
Similar to other aspects of the electric power supply value chain, the procedure behind electric power generation is complex. Electric power is usually generated by manipulating the relationship between magnetic fields and electricity, which are 2 parts of the same force. The easiest way to generate electric power is to rotate a coiled wire (a loop of wire or disc of copper) between the poles of a magnet (think of Faraday’s experiment). As the wire (coil) spins, it starts to build up a magnetic charge that can be discharged in the form of electricity. This is the basic process – the spinning of the “generator”- that takes place in all power generating equipment, from the smallest generating plant for domestic use, to the ones used in factories, as well as in turbines found in power plants.
Electricity generators depend on different devices to drive the spinning of the generator, including water wheels in hydroelectric dams, large diesel engines and gas turbines. Various forms of fuel energy such as gas, coal or diesel are used to power this movement or the spinning of the generator.
The manner in which electricity is generated in Nigeria (and several other places in the world) can be illustrated as follows: imagine boiling water in a kettle until steam begins to escape from the spout of the kettle. If you put a paper fan close to the kettle’s spout, the steam from the kettle will cause the paper fan to rotate. Assume that the fan is connected to a magnet surrounded by wires, such that when the fan rotates, the magnet too rotates. As the magnet rotates, a magnetic field is created and electric power is generated. This is simply how electricity is produced but typically on a larger and more technical scale.
To produce electricity on a larger scale, rather than use a kettle, a boiler is used and rather than using a paper fan, one or more turbines are used. Superheated steam is created by heating water in a large boiler. When the water turns into steam, it expands, moving against the turbine blades and causing the turbine to spin. The turbine is directly connected to the magnets in a generator by a rod or other equipment of a similar nature and as the turbine spins, the magnets surrounded by coils within the generator also spin and then generate electric power.
Transmission, Distribution & Supply
Once power is generated, it needs to be wheeled to the consumers. This movement is done via transmission and distribution power lines. Transmission is done via higher voltage lines, whilst distribution to the end user is effected through lower voltage distribution power lines. In the mix, there are transformers and sub-stations that step the voltage up or down between different types of power lines.
The sub-station steps up (notionally increases) the voltage of the power produced by the power plant and then sends same into the transmission system before various transformers step-down (decrease) the voltage going into the various distribution networks.
Transmission refers to the wheeling of electricity from the power plant to a sub-station through high voltage power lines. Electricity is better able to be transported over long distances if it is wheeled at a very high voltage.
Distribution, on the other hand, refers to the extensive transfer of electricity from a sub-station to consumers using lower voltage lines. The transmission and distribution system transports the generated electric power from a power plant to a wide variety of consumers. The system has the duty of moving or wheeling electric power through its web of constituents. The end-goal is to make electric power available to individual consumers.
The transmission and distribution system consists of switchyards, transmission lines, sub-stations and distribution lines. On the transmission side, the primary components are transmission lines and the switchyards. The switchyard connects the transmission and distribution system to the power plant and the grid. The grid consists of a system of interconnected power lines that provide ways to route power between any 2 or more locations. For more information on electric power, please read the text on electric power by Ayodele Oni.
Ayodele Oni, (ayodeleoni@outlook.com), a solicitor, specializes in international energy investment law and policy and holds a mini MBA in power & electricity. You can follow e on twitter @ayodelegoni