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Electrical grid

technology Maturity 11-13 Next article →

An electrical grid is an interconnected network used to deliver electricity from producers to consumers.

Electricity Grid Schematic English
Electricity Grid Schematic English

This system is essential for modern life, providing the energy needed for homes, industries, and cities. The grid consists of several vital components working together. These include power stations, electrical substations, transmission lines, and distribution networks. By connecting these parts, the grid can move electricity across vast distances. It can range in size from a small local system to a massive network covering entire continents.

Electricity grid simple- North America
Electricity grid simple- North America

The process of delivering power follows a specific sequence of steps. First, electricity is created at power stations through generation. This often uses heat engines driven by fossil fuels, nuclear energy, or geothermal sources. It can also use the kinetic energy of wind or water, or sunlight through photovoltaics.

Turbogenerator01
Turbogenerator01

Once generated, the electricity moves to a step-up substation. These substations use transformers to raise the voltage. High voltage is necessary because it allows power to travel long distances more efficiently with lower currents. The power then travels through a web of transmission lines.

500kV 3-Phase Transmission Lines
500kV 3-Phase Transmission Lines

To prevent total failure, these networks are built with redundant pathways to reroute power if a line fails.

After transmission, the electricity must be prepared for safe use. It reaches a step-down substation, which lowers the voltage for industrial use or further distribution.

A network diagram of the 'nesta case1354 pegase high voltage' electrical power system
A network diagram of the 'nesta case1354 pegase high voltage' electrical power system

Finally, distribution substations lower the voltage again to the required service level. This electricity is then carried by distribution lines to individual customers. Most transmission uses three-phase alternating current (AC). This method is more efficient than single-phase because it can deliver more power using shared wires. While AC is common, high-voltage direct current (HVDC) is used for very long distances. HVDC can have half the losses of AC and is very efficient for moving energy across huge gaps.

Electrical grids are categorized by their size and how they operate. A microgrid is a small, local grid that is usually part of a larger system. However, a microgrid can disconnect and operate on its own during an outage. This process is called islanding. On a much larger scale, there are wide area synchronous grids. These are regional networks that operate at a synchronized frequency. For example, North America has four major interconnections: the Western, Eastern, Quebec, and Texas interconnections. These run at a nominal 60 Hz. In contrast, European grids typically run at 50 Hz. The largest is the Continental Europe synchronous grid, which has 667 gigawatts (GW) of generation capacity.

There is also a conceptual plan for even larger systems called super grids or mega grids. These are wide-area transmission networks designed to trade massive volumes of electricity across great distances. Super grids are seen as a key technology to help mitigate global warming. They can support a global energy transition by smoothing out the fluctuations of wind and solar energy. These systems typically rely on HVDC technology. The latest HVDC lines are incredibly efficient, losing only 1.6% of energy per 1000 km. By connecting different regions, super grids allow areas to share cheap energy, such as hydro power or wind power, depending on the season.

Connecting different grids offers many benefits, but it also brings risks. Synchronous zones allow for pooling generation and load, which lowers costs and provides mutual assistance during disturbances. However, a problem in one part of a wide-area grid can affect everyone. In 2018, a dispute between Kosovo and Serbia caused Kosovo to use more power than it produced. This caused the frequency across the entire Continental Europe grid to drop to 49.996 Hz. This drop was significant enough to cause certain types of clocks to run six minutes slow. Additionally, as grids modernize with computer technology, they face new cyber threats and security risks.

Despite the widespread use of electricity, many people still lack access to the grid. In 2017, approximately 840 million people had no access to grid electricity. This group represents about 11% of the world's population. This was an improvement from 2010, when 1.2 billion people were without access. As electrification efforts increase, the number of connected people continues to grow. The goal for many regions is to increase the Electricity Interconnection Level (EIL). Within the EU, targets have been set to reach 10% by 2020 and 15% by 2030.

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🖼️ Images & Media (10)
File:Electricity grid simple- North America.svg
Electricity grid simple- North America.svg
File:TREC-Map-en.jpg
TREC-Map-en.jpg
File:Turbogenerator01.jpg
Turbogenerator01.jpg
File:500kV 3-Phase Transmission Lines.png
500kV 3-Phase Transmission Lines.png
File:A network diagram of the 'nesta case1354 pegase high voltage' electrical power system.png
A network diagram of the 'nesta case1354...
File:Electricity Grid Schematic English.svg
Electricity Grid Schematic English.svg
File:20241206 Grid energy storage.svg
20241206 Grid energy storage.svg
File:20241201 Power grid storage energy flow - daily.svg
20241201 Power grid storage energy flow -...
File:20110313-TokyoTower.jpg
20110313-TokyoTower.jpg
File:Toronto ON 2003 Blackout.jpg
Toronto ON 2003 Blackout.jpg
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