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Electrical Aspects
Published in Frank R. Spellman, The Science of Wind Power, 2022
All materials differ in their atomic structure and therefore in their ability to resist the flow of an electric current. The measure of the ability of a specific material to resist the flow of electricity is called its resistivity, or specific resistance—the resistance in ohms offered by unit volume (the circular-mil-foot) of a substance to the flow of electric current. Resistivity is the reciprocal of conductivity (i.e., the ease by which current flows in a conductor). A substance that has a high resistivity will have a low conductivity, and vice versa.
Operating Wisely
Published in Carl Bozzuto, Boiler Operator's Handbook, 2021
Electricity is different but it is not a dark and mysterious thing that is beyond the understanding of a competent boiler operator. Electric current is nothing more than the flow of electrons through a circuit. There are only two basic things that must be known about electricity, and the rest will fall into place. For electricity to work, there has to be a closed circuit. A circuit is a path that the electricity flows through. Break the circuit anywhere so that it is not a closed path and electric current cannot flow through it. The second thing is that there has to be something in that circuit that produces electrical current. If electric current is not flowing through the circuit, the circuit is not doing anything. That is it—create a circuit to make electricity work and break the circuit to stop it. When the path is complete so that current can flow, it is called a closed circuit. Whenever there is a break in the circuit, it is called an open circuit. A “break” is typically undesirable, whereas the “open” circuit is a normal interruption in the circuit.
DC Distribution & the Smart Grid
Published in Clark W. Gellings, The Smart Grid: Enabling Energy Efficiency and Demand Response, 2020
Alternating current (AC) is electricity that changes direction at regular intervals. It builds to a maximum voltage in one direction, decreases to zero, builds up to a maximum in the opposite direction, and then returns to zero once more. This complete sequence, or cycle, repeats, and the rate at which it repeats is called the frequency of the current. In the U.S., the AC power provided to a home outlet has a frequency of 60 cycles per second. This is expressed as 60 hertz (Hz), the hertz being a unit equal to one cycle per second.
Developing a conceptual model for the environmental management of power plant wastes
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2018
Reza Samadi, Jafar Nouri, Abdul Reza Karbassi, Reza Arjomandi
Electricity could be generated in a power plant based on the combustion of fossil fuels, which converts chemical energy into heat and then uses heat to turn turbines and generators. From an environmental viewpoint, the type of fuel as well as the method of electricity generation has considerable importance (Shafipour and Farsiabi, 2007). In Iran, about 90% of the total electricity (263 billion kWh in 2013) is supplied through a variety of thermal power plants (steam, gas, and combined-cycle). The combustion of fossil fuels in power plants in order to generate electricity has led to the emission of air, water, soil, and even sound pollutants to the environment, which has attracted the attention of ecologists, the energy sector, and even the public. The subject receiving less attention is solid and semisolid wastes that are produced directly or indirectly as a result of combustion, water supply systems, and wastewater treatment in power plants. The quality and quantity of solid waste depend on different factors, including the type of power plant and the type of fuel consumed.
Chinese nuclear energy politics: Viewpoint on energy
Published in Energy Sources, Part B: Economics, Planning, and Policy, 2018
Researchers are searching for a clean energy solution due to the energy crisis and environmental problems. There are various methods for electricity generation, including thermal methods such as combustion as well as wind and solar energies. These methods have been used in most developed countries but other electricity generation methods such as nuclear energy are not common due to their high technology and uranium resource constraints as the primary fuel. However, since nuclear power is able to produce significant amounts of energy for a small amount of fuel, this method has recently attracted attention of most countries. Lack of energy sources and their costs are the reasons why some countries use nuclear energy. Unlike western countries of this continent, the eastern Asian countries are faced with severe shortage of fossil fuels such as oil and natural gas, imposing high costs on them. Some of these countries include Japan, China, South Korea, Malaysia, and Taiwan. As the most populous country in the world, China is faced with a severe energy crisis. Among other methods such as wind and solar energies, this country has long-term plans for running nuclear power plants, especially in the coastal cities.