Mains electricity, also known by the American English terms utility power, power grid, domestic power, and wall power, or in some parts of Canada as hydro, is a general-purpose alternating-current (AC) electric power supply. It is the form of electrical power that is delivered to homes and businesses through the electric grid in many parts of the world. People use this electricity to power everyday items—such as domestic appliances, televisions and lamps—by plugging them into a wall outlet.
Electric power distribution is the final stage in the delivery of electric power; it carries electricity from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2 kV and 35 kV with the use of transformers. Primary distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage used by lighting, industrial equipment and household appliances. Often several customers are supplied from one transformer through secondary distribution lines. Commercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level.
An electricity meter, electric meter, electrical meter, energy meter, or kilowatt-hour meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device.
Demand response is a change in the power consumption of an electric utility customer to better match the demand for power with the supply. Until recently electric energy could not be easily stored, so utilities have traditionally matched demand and supply by throttling the production rate of their power plants, taking generating units on or off line, or importing power from other utilities. There are limits to what can be achieved on the supply side, because some generating units can take a long time to come up to full power, some units may be very expensive to operate, and demand can at times be greater than the capacity of all the available power plants put together. Demand response seeks to adjust the demand for power instead of adjusting the supply.
Advanced Distribution Automation (ADA) is a term coined by the IntelliGrid project in North America to describe the extension of intelligent control over electrical power grid functions to the distribution level and beyond. It is related to distribution automation that can be enabled via the smart grid. The electrical power grid is typically separated logically into transmission systems and distribution systems. Electric power transmission systems typically operate above 110kV, whereas Electricity distribution systems operate at lower voltages. Normally, electric utilities with SCADA systems have extensive control over transmission-level equipment, and increasing control over distribution-level equipment via distribution automation. However, they often are unable to control smaller entities such as Distributed energy resources (DERs), buildings, and homes. It may be advantageous to extend control networks to these systems for a number of reasons:
Solar power in Germany consists almost exclusively of photovoltaics (PV) and accounted for an estimated 8.2 percent of the country's gross-electricity generation in 2019. About 1.5 million photovoltaic systems were installed around the country in 2014, ranging from small rooftop systems, to medium commercial and large utility-scale solar parks. Germany's largest solar farms are located in Meuro, Neuhardenberg, and Templin with capacities over 100 MW.
The electricity sector in Honduras has been shaped by the dominance of a vertically integrated utility ; an incomplete attempt in the early 1990s to reform the sector; the increasing share of thermal generation over the past two decades; the poor financial health of the state utility Empresa Nacional de Energía Eléctrica (ENEE); the high technical and commercial losses in transmission and distribution; and the low electric coverage in rural areas.
The electricity sector in Colombia is dominated by large hydropower generation (65%) and thermal generation (35%). Despite the country's large potential in new renewable energy technologies, this potential has been barely tapped. A 2001 law designed to promote alternative energies lacks certain key provisions to achieve this objective, such as feed-in tariffs, and has had little impact so far. Large hydropower and thermal plants dominate the current expansion plans. The construction of a transmission line with Panama, which will link Colombia with Central America, is underway.
The electricity sector in Argentina constitutes the third largest power market in Latin America. It relies mostly on thermal generation and hydropower generation (36%). The prevailing natural gas-fired thermal generation is at risk due to the uncertainty about future gas supply.
The electricity sector in New Zealand uses mainly renewable energy sources such as hydropower, geothermal power and increasingly wind energy. As of 2019, 82% of energy for electricity generation is from renewable sources, making New Zealand one of the lowest carbon dioxide emitting countries in terms of electricity generation. Electricity demand grew by an average of 2.1% per year from 1974 to 2010 but decreased by 1.2% from 2010 to 2013.
The power sector in the Dominican Republic has traditionally been, and still is, a bottleneck to the country's economic growth. A prolonged electricity crisis and ineffective remedial measures have led to a vicious cycle of regular blackouts, high operating costs of the distribution companies, large losses including electricity theft through illegal connections, high retail tariffs to cover these inefficiencies, low bill collection rates, a significant fiscal burden for the government through direct and indirect subsidies, and very high costs for consumers as many of them have to rely on expensive alternative self-generated electricity. According to the World Bank, the revitalization of the Dominican economy depends greatly on a sound reform of the sector.
The electricity sector in Brazil is the largest in South America. Its capacity at the end of 2020 was 175,407 MW. The installed capacity grew from 11,000 MW in 1970 with an average yearly growth of 5.8% per year. Brazil has the largest capacity for water storage in the world, being highly dependent on hydroelectricity generation capacity, which meets over 70% of its electricity demand. The national grid runs at 60 Hz and is powered 80% from renewable sources. This dependence on hydropower makes Brazil vulnerable to power supply shortages in drought years, as was demonstrated by the 2001-2002 energy crisis.
Electricity pricing can vary widely by country or by locality within a country. Electricity prices are dependent on many factors, such as the price of power generation, government taxes or subsidies, local weather patterns, transmission and distribution infrastructure, and multi-tiered industry regulation. The pricing or tariffs can also differ depending on the customer-base, typically by residential, commercial, and industrial connections.
Grid parity occurs when an alternative energy source can generate power at a levelized cost of electricity (LCOE) that is less than or equal to the price of power from the electricity grid. The term is most commonly used when discussing renewable energy sources, notably solar power and wind power. Grid parity depends upon whether you are calculating from the point of view of a utility or of a retail consumer.
Paraguay is one of the few countries in Latin America that has maintained an integrated public monopoly on electricity. Hydropower comprises nearly 100 percent of electricity in Paraguay; 90 percent of generated energy is exported, with neighboring Argentina and Brazil receiving the majority. Paraguay is one of the world's largest electricity net exporters.
The electricity sector in Guyana is dominated by Guyana Power and Light (GPL), the state-owned vertically integrated utility. Although the country has a large potential for hydroelectric and bagasse-fueled power generation, most of its 226 MW of installed capacity correspond to thermoelectric diesel-engine driven generators.
A home fuel cell or a residential fuel cell is an electrochemical cell used for primary or backup power generation, similar to larger industrial stationary fuel cells, but built at a smaller scale for residential use. These fuel cells are usually based on combined heat and power (CHP) or micro combined heat and power (MicroCHP) technology, generating both power and heated water or air.
The electricity sector of the United States includes a large array of stakeholders that provide services through electricity generation, transmission, distribution and marketing for industrial, commercial, public and residential customers. It also includes many public institutions that regulate the sector. In 1996, there were 3,195 electric utilities in the United States, of which fewer than 1,000 were engaged in power generation. This leaves a large number of mostly smaller utilities engaged only in power distribution. There were also 65 power marketers. Of all utilities, 2,020 were publicly owned, 932 were rural electric cooperatives, and 243 were investor-owned utilities. The electricity transmission network is controlled by Independent System Operators or Regional Transmission Organizations, which are not-for-profit organizations that are obliged to provide indiscriminate access to various suppliers in order to promote competition.
The electricity sector in Taiwan ranges from generation, transmission, distribution and sales of electricity, covering Taiwan island and its offshore islands.
