The world’s longest power transmission lines

29 January 2020 (Last Updated July 27th, 2020 17:18)

High-voltage direct current (HVDC) has emerged as the preferred transmission technology for long-distance bulk power supply. Brazil houses three of the world’s longest power transmission lines. Power Technology lists the longest operational transmission lines.

The world’s longest power transmission lines

Which are the longest transmission lines in the world?

1. Belo Monte-Rio de Janeiro transmission line, Brazil

2. Rio Madeira transmission link

3. Belo Monte-Estreito transmission line, Brazil – 2,092km

4. Jinping-Sunan transmission line, China

5. Xiangjiaba-Shanghai transmission line, China

6. Inga-Kolwezi transmission line, Congo

7. Talcher-Kolar transmission link, India

1. Belo Monte-Rio de Janeiro transmission line, Brazil – 2,543km

The 2,543km-long Belo Monte-Rio de Janeiro transmission line in Brazil is an 800kV ultra-high-voltage direct current (UHVDC) line that transmits electricity from the 11.2GW Belo Monte hydroelectric power plant located in Para to Rio de Janeiro, Brazil.

Construction of the transmission line, which is also known as the Belo Monte UHVDC Bipole II line, was started in September 2017 and completed in April 2019. The overhead transmission line, that has transmission towers 105m and taller, crosses 80 cities along its route from the Amazon to Brazil’s southeast coast. The line has two power converter stations and is capable of transmitting 4GW of electricity.

The Belo Monte- Rio de Janeiro transmission line was built by State Grid Corporation of China (SGCC) as part of China’s Belt and Road Initiative (BRI). It is the second 800kV UHVDC line to be built and operated by SGCC in Brazil, after the Belo Monte UHVDC Bipole I line, which was completed at the end of 2017.

2. Rio Madeira transmission link, Brazil – 2,385km

The Rio Madeira transmission link in Brazil is a 600kV high-voltage direct current (HVDC) bipolar line commissioned in November 2013. It is capable of transmitting 7.1GW of power.

The Rio Madeira HVDC link transmits electricity from the Santo Antônio and Jirau hydropower plants on the banks of the Madeira River in north-west Brazil to major load centres in south-eastern Brazil. It connects the Porto Velho Collector Substation in the state of Rondônia to the Araraquara-2 Substation in the state of São Paulo.

The HVDC transmission line was constructed in 24 months by Interligação Elétrica do Madeira (IE Madeira), a consortium comprised of three major Brazilian energy providers. ABB supplied power equipment for three HVDC stations. Alstom supplied two HVDC bi-pole converter stations and four HVDC power converter transformers for the project.

3. Belo Monte-Estreito transmission line, Brazil – 2,092km

The Belo Monte-Estreito transmission line, also known as the Belo Monte UHVDC Bipole I line, is the first 800kV UHVDC transmission line to be constructed for delivering electricity from the Belo Monte hydroelectric power station in northern Brazil to south-east Brazil.

Commissioned in December 2017, the 2,092km-long UHVDC line originates from Xingu in Para and terminates at Estreito in Minas Gerais. The Belo Monte UHVDC Bipole I line is capable of transmitting 4GW of electricity.

The Belo Monte-Estreito UHVDC transmission line is owned and operated by Belo Monte Transmissora de Energia (BMTE), which is a special purpose company comprising China’s State Grid Corporation (51 %), Fumas (24.5%) and Eletronorte (24.5%). Fumas and Eletronorte are the subsidiaries of Brazil’s state-owned Eletrobras.

4. Jinping-Sunan transmission line, China – 2,090km

The Jinping-Sunan transmission link in China is an 800kV UHVDC transmission line. Owned by State Grid Corporation of China (SGCC), the 7.2GW transmission link was put into operation in December 2012.

The line passes through eight Chinese provinces to transmit power generated from Guandi, Jinping, and Sichuan hydroelectric plants located on the Yalong River in central-western Sichuan province to the industrialised coastal area of Jiangsu province in eastern China. The AC voltage at both ends of the line is 525kV.

The transmission project was approved by the government in November 2008 and involved an investment of approximately CNY22bn ($3.5bn). ABB designed and engineered the project in association with SGCC and local Chinese partners. ABB also supplied the key components of the project, including 800kV UHVDC electrical transformers for both converter stations.

5. Xiangjiaba-Shanghai transmission line, China – 1,980km

The Xiangjiaba-Shanghai transmission line, with an overhead length of 1,980km, is an 800kV, 7.2GW line, owned by SGCC. The world’s first ever UHVDC transmission line, it started commercial operation in July 2010.

The Xiangjiaba-Shanghai link transmits power from the Xiangjiaba hydropower plant located in south-west China to the country’s major industrial and commercial hub, Shanghai. The link comprises a single overhead line and 28 high/ultra-high-voltage converter transformers. The AC voltage at both ends of the line is 525kV.

The UHVDC transmission project was approved by the government in April 2007 and completed in 30 months. ABB, under a turnkey contract, provided the overall system design, in addition to supplying the key components such as high and ultra-high-voltage power converter transformers, thyristor valves, DC and AC switchyard equipment, and the HVDC control system.

6. Inga-Kolwezi transmission line, Congo – 1,700km

Congo’s 1,700km-long Inga-Kolwezi transmission line, formerly known as the Inga-Shaba link, is a 500kV line with a rated capacity of 560MW. It is owned and operated by Democratic Republic of Congo’s (DRC) national electricity utility, Société Nationale d’Electricité (Snel).

The Inga-Kolwezi HVDC link carries power from the Inga Falls hydropower station on the Congo River to the copper mining district of Katanga in south-eastern Congo. Brought into service in 1982, it was the world’s longest transmission line at that time. The AC voltage at both ends of the line is 220kV.

The key components for the project, including the converter stations, were supplied by ABB, which was also awarded a contract to refurbish the line with new thyristor valves, new high-voltage apparatus, and a new control and protection system to enhance the efficiency and reliability of the line in 2009.

7. Talcher-Kolar transmission link, India – 1,450km

The 500kV HVDC transmission line Talcher-Kolar is also known as the East-South transmission link. It has a rated capacity of 2,500MW. Owned by Power Grid Corporation of India, Talcher-Kolar was the world’s second-longest transmission link at the time of commissioning in February 2003.

The Talcher-Kolar transmission link transmits electricity from the Talcher power generation centre in the East Indian state of Orissa to Kolar near Bangalore, the capital city of southern state Karnataka. The bipolar transmission line had the capacity to transmit 2,000MW of power at the time of commissioning, but upgraded to 2,500MW in 2007. Siemens built the converter stations for the Talcher-Kolar HVDC link.

Power Grid Corporation of India is also building India’s first UHVDC transmission line, the 1,728km 800kV North-East Agra UHVDC link, which is capable of transmitting 8,000MW. The project is being delivered by ABB and is scheduled for commissioning in 2015. It will be the longest power transmission line in India, upon commissioning.

NRI Energy Technology