History of Electricity Grid Timeline

With the passage of the Public Utility Holding Company Act, electric utilities in the United States were recognized as public goods of importance and were given outlined restrictions and regulatory oversight of their operations.

Image source: Public Utility Holding Company Act of 1935

The Energy Policy Act of 1992 required transmission line owners to allow electric generation companies open access to their network, leading to a restructuring of the electric industry to create competition in power generation.

The Energy Policy Act of 2005 allowed incentives and loan guarantees for alternative energy production and advanced innovative technologies that avoided greenhouse gas emissions.

Within the EU, member states have set a target of national grids reaching 10% interconnection capacity by 2020, and 15% by 2030, to strengthen cross-border electricity flows.

Image source: Energy policy of the European Union

From 1958 to 1998, China's electrified railway network grew to reach 6,200 miles (10,000 kilometres), a major expansion of rail electrification over four decades.

Image source: Railway electrification

In August 1961, the electrification of the Baoji-Fengzhou section of the Baocheng Railway was completed and delivered for operation, becoming China's first electrified railway.

Image source: Baoji–Chengdu railway

As of the end of 2017, China's electrified railway mileage reached 54,000 miles (87,000 kilometres), making it one of the most extensive electrified rail networks in the world.

In 2019, State Grid completed power supply projects for China's important electrified railways, such as the Jingtong Railway, Haoji Railway, and Zhengzhou-Wanzhou high-speed railway, providing power supply guarantee for 110 traction stations, with cumulative power line construction length reaching 6,586 kilometres.

Image source: State Grid Corporation of China

In China's current railway electrification system, the State Grid Corporation of China is an important power supplier, supporting the vast electrified rail network across the country.

Starting on May 29, 1986, the end user service voltage in France progressively changed to 230/400 V ±10%, aligning with broader European voltage harmonization efforts.

Within ENTSO-E in 2008, over 350,000 megawatt hours were sold per day on the European Energy Exchange (EEX), illustrating the scale of cross-border electricity trading in Europe's interconnected grids.

Although electrical grids are widespread, as of 2016, 1.4 billion people worldwide were not connected to an electricity grid, highlighting persistent global inequality in energy access.

Image source: Electrification

By 2017, 11% of the world's population had no access to grid electricity, down from 1.2 billion people in 2010, showing steady progress toward universal electrification.

In 2018, Kosovo used more power than it generated due to a dispute with Serbia, leading to the phase across the whole synchronous grid of Continental Europe lagging behind what it should have been.

Image source: Continental Europe Synchronous Area

The latest generation of HVDC power lines can transmit energy with losses of only 1.6% per 1000 km, making long-distance bulk power transfer increasingly efficient.

Image source: High-voltage direct current

The North American Electric Reliability Corporation gained binding powers in the United States in 2006, and holds advisory powers in applicable parts of Canada and Mexico, strengthening grid reliability standards across North America.

Image source: North American Electric Reliability Corporation

In 2017, a utility in Southern California successfully demonstrated the use of a battery energy storage system to provide a black start, firing up a combined cycle gas turbine from an idle state.

Image source: Battery energy storage system

As of 2020, the largest form of grid energy storage is dammed hydroelectricity, including both conventional hydroelectric generation and pumped storage hydroelectricity.

Image source: Grid energy storage