Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a transmission network. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid.
In the electricity sector in the United Kingdom, the National Grid is the high-voltage electric power transmission network serving Great Britain, connecting power stations and major substations and ensuring that electricity generated anywhere on it can be used to satisfy demand elsewhere. The network covers the great majority of Great Britain and several of the surrounding islands. It does not cover Northern Ireland, which is part of a single electricity market with the Republic of Ireland.
The electricity sector in Canada has played a significant role in the economic and political life of the country since the late 19th century. The sector is organized along provincial and territorial lines. In a majority of provinces, large government-owned integrated public utilities play a leading role in the generation, transmission, and distribution of electricity. Ontario and Alberta have created electricity markets in the last decade to increase investment and competition in this sector of the economy.
The East–West Interconnector is a 500 MW high-voltage direct current submarine and subsoil power cable which connects the Irish and British electricity markets. The project was developed by the Irish national grid operator EirGrid.
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.
Nicaragua is the country in Central America with the lowest electricity generation, as well as the lowest percentage of population with access to electricity. The unbundling and privatization process of the 1990s did not achieve the expected objectives, resulting in very little generation capacity added to the system. This, together with its high dependence on oil for electricity generation, led to an energy crisis in 2006 from which the country has not fully recovered yet.
Hydro-Québec's electricity transmission system is an international electric power transmission system centred in Quebec, Canada. The system pioneered the use of very high voltage 735-kilovolt (kV) alternating current (AC) power lines that link the population centres of Montreal and Quebec City to distant hydroelectric power stations like the Daniel-Johnson Dam and the James Bay Project in northwestern Quebec and the Churchill Falls Generating Station in Labrador.
The synchronous grid of Continental Europe is the largest synchronous electrical grid in the world. It is interconnected as a single phase-locked 50 Hz mains frequency electricity grid that supplies over 400 million customers in 24 countries, including most of the European Union. In 2009, 667 GW of production capacity was connected to the grid, providing approximately 80 GW of operating reserve margin. The transmission system operators operating this grid formed the Union for the Coordination of Transmission of Electricity (UCTE), now part of the European Network of Transmission System Operators for Electricity (ENTSO-E).
An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover whole countries or continents. It consists of:
A wide area synchronous grid is a three-phase electric power grid that has regional scale or greater that operates at a synchronized utility frequency and is electrically tied together during normal system conditions. Also known as synchronous zones, the most powerful is the Northern Chinese State Grid with 1,700 gigawatts (GW) of generation capacity, while the widest region served is that of the IPS/UPS system serving most countries of the former Soviet Union. Synchronous grids with ample capacity facilitate electricity trading across wide areas. In the ENTSO-E in 2008, over 350,000 megawatt hours were sold per day on the European Energy Exchange (EEX).
There is a large array of stakeholders that provide services through electricity generation, transmission, distribution and marketing for industrial, commercial, public and residential customers in the United States. 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 to promote competition.
The electricity sector of Uruguay has traditionally been based on domestic hydropower along with thermal power plants, and reliant on imports from Argentina and Brazil at times of peak demand. Over the last 10 years, investments in renewable energy sources such as wind power and solar power allowed the country to cover in early 2016 94.5% of its electricity needs with renewable energy sources.
The North Sea Link is a 1,400 MW high-voltage direct current submarine power cable between Norway and the United Kingdom.
Energy in Malta describes energy production, consumption and import in Malta. Malta has no domestic resource of fossil fuels and no gas distribution network, and relies overwhelmingly on imports of fossil fuels and electricity to cover its energy needs. Since 2015, the Malta–Sicily interconnector allows Malta to be connected to the European power grid and import a significant share of its electricity.
The electricity sector in Iceland is 99.98% reliant on renewable energy: hydro power, geothermal energy and wind energy.
Denmark's western electrical grid is part of the Synchronous grid of Continental Europe whereas the eastern part is connected to the Synchronous grid of Northern Europe via Sweden.
Electricity in Cyprus is managed by the Electricity Authority of Cyprus. Power is primarily generated at three fuel oil-burning stations but the use of distributed renewable energy is expanding.
The electricity sector in Macau ranges from generation, transmission, distribution and sales of electricity in Macau, China.
The electrical power grid that powers Northern America is not a single grid, but is instead divided into multiple wide area synchronous grids. The Eastern Interconnection and the Western Interconnection are the largest. Three other regions include the Texas Interconnection, the Quebec Interconnection, and the Alaska Interconnection. Each region delivers power at a nominal 60 Hz frequency. The regions are not usually directly connected or synchronized to each other, but there exist some HVDC interconnectors. The Eastern and Western grids are connected with 1.32 GW.
EuroAfrica Interconnector is a HVDC interconnector and submarine power cable between the Greek, Cypriot, and Egypt power grids. The Interconnector is an energy highway bridging Africa and Europe. It will have a capacity to transmit 2,000 megawatts of electricity in either direction. Annual transmission capacity will be rated at 17.5 TWh, much more than the annual production at the Aswan Dam power stations. President of Egypt Abdel Fattah el-Sisi, President of Cyprus Nicos Anastasiades and Prime Minister of Greece Kyriakos Mitsotakis, issued a joint declaration at the conclusion of the 7th Trilateral Summit, held in Cairo on October 8, 2019, in which they expressed their desire to continue strengthening their cooperation in matters of energy. In particular, the joint declaration by the three leaders stated they recognised the importance of establishing an electrical grid between Egypt, Cyprus and Greece, building on the framework agreement between the Egyptian Electricity Holding Company and the Euro Africa Interconnector Company on 22 May 2019.
