Global Extra High Voltage Transmission Market Outlook, 2031

Extra high voltage transmission refers to bulk power networks that operate at very high voltages, generally from about 345 kilovolts to 765 kilovolts for alternating current, with ultra-high voltage systems at 1,000 kilovolts AC and plus or minus 800 to 1,100 kilovolts direct current used in the largest corridors. These networks move large blocks of electricity over hundreds or thousands of kilometres from power plants, renewable zones and interconnectors to load centres with lower losses than lower-voltage lines. Typical equipment includes lattice steel towers, multi-conductor bundles, high-voltage cables, power transformers and shunt reactors, gas-insulated and air-insulated switchgear, series compensation, flexible AC transmission devices and HVDC converter stations. A single 765 kilovolt AC circuit can carry roughly 2,000 to 3,000 megawatts, and modern plus or minus 800 kilovolt DC links can carry 6,000 to 8,000 megawatts or more. Leading suppliers and contractors include Hitachi Energy, Siemens Energy, GE Vernova, Mitsubishi Electric, Toshiba, TBEA, China XD, Hyosung Heavy Industries, HD Hyundai Electric, Prysmian, Nexans, NKT, Larsen and Toubro, Kalpataru Projects and KEC International, alongside grid owners such as State Grid Corporation of China and Power Grid Corporation of India. Engineering capability and factory capacity shape competition.

The market is driven by the need to connect renewable generation located far from cities, strengthen interregional transfers, serve fast-growing loads such as data centres and electrified industry, and improve resilience. Between 2024 and 2026, investment reached record levels in several regions: State Grid Corporation of China planned more than 650 billion yuan of grid investment in 2025 after completing three new ultra-high voltage lines in 2024, India expanded its 765 kilovolt and HVDC programme under its national transmission plan, the United States issued Order No. 1920 on long-term regional transmission planning, the United Kingdom approved its RIIO-3 transmission price control, and the European Commission published its European Grids Package to speed up planning and permitting. At the same time, long lead times for transformers, cables and HVDC converters, permitting delays, local opposition and the cancellation of federal financing for the Grain Belt Express in the United States showed the risks involved. Through 2031, key variables are supply chain capacity, permitting reform, cost allocation, interregional planning, HVDC adoption and the pace of renewable and data centre connections. Developers with secured manufacturing slots and strong project execution are expected to hold an advantage.

Drivers •Renewable Integration and Long-Distance Bulk Power Transfer Large wind, solar and hydro resources are often located in remote areas, deserts, offshore zones and mountains, far from the cities and industrial clusters that use the power. Extra high voltage and ultra-high voltage lines are the most efficient way to move gigawatt-scale output over long distances while keeping losses and land use per megawatt low. China's desert renewable bases, India's renewable energy zones in Rajasthan and Gujarat, North Sea offshore wind and United States wind belts all depend on new EHV corridors. National targets for renewable capacity keep the project pipeline full. Demand is strong.

•Load Growth from Data Centres, Electrification and Industrial Reshoring Electricity demand is rising after years of flat growth in many developed markets, led by data centres for cloud and artificial intelligence, electric vehicles, heat pumps, green hydrogen and new manufacturing plants. Utilities and system operators are revising load forecasts upward and planning new 345 to 765 kilovolt backbones to serve large loads that can exceed several hundred megawatts at a single site. Interregional links also improve reliability during extreme weather by sharing reserves across wider areas. Growth is solid.

Challenges •Permitting Delays, Land Acquisition and Public Opposition EHV lines cross many jurisdictions, farms, forests and communities, so route approval, environmental studies and land acquisition can take a decade or more in some countries. Landowner opposition, visual impact concerns and legal challenges often delay projects, and political changes can remove financial support, as shown by the cancellation of a federal loan guarantee for a major United States HVDC line in July 2025. Cost allocation disputes between regions and customers add further delay. Permitting reform is under way in Europe and the United States, but results take time. Uncertainty remains high.



•Supply Chain Constraints for Transformers, Cables and HVDC Equipment Global demand for large power transformers, high-voltage cables, gas-insulated switchgear and HVDC converter systems has outpaced factory capacity, with lead times for some equipment stretching to several years. Shortages of grain-oriented electrical steel, specialised insulation and skilled labour add constraints. Equipment makers are investing in new capacity, but new plants take years to reach full output. Project costs have risen sharply, and developers increasingly reserve manufacturing slots in advance through framework agreements. Price escalation affects budgets. Schedules are at risk.

Trends •Expansion of HVDC and Ultra-High Voltage Corridors HVDC technology is increasingly chosen for very long overland routes, subsea interconnectors, offshore wind connections and links between asynchronous grids, because it offers lower losses over distance and precise power-flow control. Voltage source converter technology allows multi-terminal grids and connection to weak networks. China continues to build plus or minus 800 and 1,100 kilovolt lines, India is adding new HVDC links, and Europe is planning meshed offshore grids. Standardisation of converter ratings is being pursued to speed procurement. Adoption is growing.

•Proactive, Long-Term Planning and Grid-Enhancing Technologies Regulators are moving from reactive, project-by-project approvals toward long-term, scenario-based planning that anticipates future generation and load over 20 years or more. United States Order No. 1920, the United Kingdom's centralised strategic network planning and the European Grids Package all push in this direction. Alongside new lines, operators are adopting advanced conductors, dynamic line ratings, power-flow controllers and reconductoring to raise the capacity of existing corridors faster and at lower cost. Planning and procurement are becoming more coordinated. Interest is rising.

765 kilovolt and below AC systems lead because they form the backbone of most national grids, while ultra-high voltage AC and DC systems grow fastest through long-distance renewable corridors. Extra high voltage AC systems at 345, 400, 500 and 765 kilovolts are the largest voltage segment because they form the main transmission backbone in North America, Europe, India, Latin America, the Middle East and Africa, and most new interregional lines and substation expansions are built at these levels. The 400 kilovolt class dominates in Europe, the Middle East and India's regional networks, while 500 kilovolt is common in the western United States, Brazil and parts of Asia, and 765 kilovolt is used for the highest-capacity corridors in India, the United States, South Africa and Russia. Ultra-high voltage AC at 1,000 kilovolts is used mainly in China for very high capacity regional links. HVDC systems at plus or minus 500 to 1,100 kilovolts are the fastest growing segment because they transmit large blocks of power over very long distances, connect offshore wind and link separate grids. Through 2031, HVDC and ultra-high voltage systems are expected to grow faster than the total as renewable bases expand, while 345 to 765 kilovolt AC remains the volume base for network reinforcement.

Overhead lines lead because they are the lowest-cost way to move bulk power over land, while underground and submarine cables grow fastest in urban, offshore and interconnector projects. Overhead transmission lines are the largest installation type because lattice towers and bundled conductors offer the lowest capital cost per megawatt-kilometre for long overland routes, are easier to repair and can be uprated with new conductors. Underground cable systems are used where overhead lines are impractical or not permitted, including city centres, sensitive landscapes and river crossings, and countries such as Germany have favoured underground HVDC cables for major north-south links. Submarine cables are the fastest growing type because of offshore wind connections and international interconnectors in the North Sea, Baltic, Mediterranean and between islands in Asia. Cables cost several times more than overhead lines per kilometre and require specialised manufacturing and installation vessels, which limits supply. Through 2031, cable installations are expected to grow faster than overhead lines, but overhead construction remains the largest share by length.

Lines and conductors, transformers and substations lead spending because they make up most project cost, while HVDC converter stations grow fastest through new long-distance and offshore links. Transmission lines, towers, conductors and insulators account for a major share of project spending because long routes require large quantities of steel, aluminium and installation work. Power transformers, shunt reactors and substation equipment, including gas-insulated and air-insulated switchgear, circuit breakers, instrument transformers and protection systems, form another large component, and transformer shortages have pushed up prices and lead times. HVDC converter stations are the fastest growing component because each long-distance or offshore link requires two or more converter terminals with valves, converter transformers, filters and control systems. Cables, accessories and joints are growing with underground and subsea projects. Reactive power compensation, including static VAR compensators and STATCOMs, supports voltage stability as converter-based generation increases. Engineering, procurement, construction and services add significant value. Through 2031, converter stations and cables are expected to grow faster than lines and substations.

Utilities and transmission system operators lead because they own and operate most EHV networks, while independent and merchant developers grow through competitive tenders and private interconnectors. Utilities and transmission system operators are the largest end-user group because they plan, own, operate and maintain most EHV networks under regulated business models, and they account for the bulk of new line, substation and interconnector investment. State-owned grid companies dominate in China, India, the Middle East and much of Africa, while investor-owned utilities and regulated transmission companies lead in North America and Europe. Independent transmission developers are growing through competitive tenders in India, Brazil, the United States and the United Kingdom, where private companies build and operate lines under long-term contracts. Merchant developers are pursuing HVDC interconnectors and renewable export lines funded by long-term capacity contracts. Renewable developers and large industrial or data centre customers occasionally fund dedicated connection assets. Through 2031, competitive and private ownership models are expected to grow faster, while utilities and system operators remain the largest buyers.

Asia-Pacific leads extra high voltage transmission through China's ultra-high voltage programme and India's 765 kilovolt and HVDC expansion, while North America and Europe accelerate long-term planning, and Latin America and the Middle East and Africa build new corridors for renewables and interconnection. North America is entering a new investment cycle after years of limited interregional transmission construction. Load growth from data centres, manufacturing and electrification, along with renewable integration and extreme-weather resilience needs, has pushed utilities and regional transmission organisations to plan new 345, 500 and 765 kilovolt lines. Order No. 1920, issued in May 2024 and modified in November 2024 by Order No. 1920-A, requires long-term regional planning over a 20-year horizon with scenarios and state input. Large regional portfolios in the Midcontinent and Texas include new 765 kilovolt backbones. However, permitting remains slow, interregional cost allocation is contentious, and federal support has shifted, with the Department of Energy cancelling a 4.9 billion dollar conditional loan guarantee for the Grain Belt Express HVDC line in July 2025. Transformer and cable shortages have extended project timelines. Canada is expanding interties and hydro export lines, and Mexico is reinforcing its grid to support nearshoring. By 2031, growth is expected from regional backbones, data centre connections and HVDC links, though execution will depend on permitting and supply chain capacity.

Europe is investing heavily in EHV networks to integrate offshore wind, solar and cross-border trading and to replace ageing assets. Germany's SuedLink and other north-south HVDC corridors, mostly underground, received further planning approvals in 2025, while the North Sea countries are planning offshore hubs and interconnectors. The United Kingdom's regulator published RIIO-3 final determinations in December 2025, approving an initial 10.3 billion pounds for electricity transmission for April 2026 to March 2031 with expected growth as major projects are added. The European Commission published the European Grids Package in December 2025, proposing faster permitting, more coordinated EU-wide planning and better connection procedures. The Iberian blackout of April 2025 highlighted the importance of voltage control and system strength. Supply chain constraints for cables, converters and transformers remain a key bottleneck, and local opposition affects overhead lines. By 2031, growth is expected from offshore grids, interconnectors and reinforcement of national backbones, supported by long-term framework contracts with suppliers.

Asia-Pacific is the largest and fastest growing region. China operates the world's most extensive ultra-high voltage network, and State Grid Corporation of China reported 38 ultra-high voltage lines after completing three in 2024, with grid investment planned at more than 650 billion yuan for 2025 to connect desert renewable bases and move power from west to east. China Southern Power Grid is also expanding. India is building a large 765 kilovolt and HVDC network under its national transmission plan to 2032 to integrate about 500 gigawatts of non-fossil capacity, with many projects awarded through tariff-based competitive bidding to Power Grid Corporation of India and private developers. Japan is strengthening interregional links between its 50 and 60 hertz zones, South Korea is planning HVDC lines to move power from coastal plants and offshore wind to the Seoul area, and Australia is building new 500 kilovolt interconnectors and renewable energy zone networks. Southeast Asia is studying the ASEAN power grid. By 2031, the region is expected to account for most global EHV investment.

Latin America is building new EHV corridors to connect hydro, wind and solar resources to major demand centres. Brazil has one of the world's largest transmission networks, including plus or minus 800 kilovolt HVDC lines from the Amazon, and holds regular transmission auctions that attract domestic and international investors to build 500 kilovolt and HVDC lines, particularly to carry wind and solar power from the northeast to the southeast. Chile is building a long HVDC line to move solar power from the north to the centre of the country, and Colombia, Peru and Argentina are expanding their 500 kilovolt systems. Mexico plans to reinforce its national grid to support industrial growth. Barriers include financing costs, environmental licensing, social consent in indigenous and rural areas and currency volatility. By 2031, growth is expected from competitive transmission auctions, renewable integration and regional interconnections, with Chinese, European and local contractors competing for projects.

The Middle East and Africa are expanding EHV networks to support rapid demand growth, renewable programmes and regional interconnection. Saudi Arabia, the United Arab Emirates and Oman are building 380 and 400 kilovolt lines and HVDC links to integrate large solar and wind projects, and the Gulf Cooperation Council Interconnection Authority is reinforcing regional links. Egypt is expanding its 500 kilovolt network and developing interconnections with Saudi Arabia and Europe. South Africa needs new 400 and 765 kilovolt lines to connect renewable projects in the Northern and Western Cape, and has opened private participation in transmission. East and West African power pools are developing cross-border lines to share hydro and gas resources. Barriers include financing, utility creditworthiness, security and limited local manufacturing. By 2031, growth is expected from Gulf renewable and interconnection projects, Egyptian and North African export plans and regional African power pool lines, often supported by development finance institutions.

December 2025 – European Commission publishes the European Grids Package: The package proposes a new trans-European energy networks framework, faster permit-granting and guidance on grid connections, aiming to speed up cross-border and national EHV projects.

December 2025 – Ofgem publishes RIIO-3 final determinations for transmission: The United Kingdom regulator approved an initial 10.3 billion pounds for electricity transmission for its new five-year price control period, with total network investment expected to grow as major projects are added.

July 2025 – United States Department of Energy cancels Grain Belt Express loan guarantee: The department terminated a 4.9 billion dollar conditional loan guarantee for the long-distance HVDC line, highlighting political and financing risks for interregional transmission.

January 2025 – State Grid Corporation of China plans record grid investment: The company said it would invest more than 650 billion yuan in 2025, after completing three new ultra-high voltage lines in 2024 to reach 38 in operation.

May 2024 – FERC issues Order No. 1920 on long-term transmission planning: The order requires 20-year, scenario-based regional planning and cost allocation, and was modified in November 2024 by Order No. 1920-A to strengthen the role of states.


Considered in this report
• Historic Year: 2020
• Base Year: 2025
• Estimated Year: 2026
• Forecast Year: 2031

Aspects covered in this report
• Global Extra High Voltage Transmission Market with its segments and regional outlook
• Various drivers and challenges
• Ongoing trends and developments
• Key developments and regulatory milestones

By Voltage Level
• •345 to 400 kilovolt AC
• •500 to 765 kilovolt AC
• •Ultra-high voltage AC (1,000 kilovolt)
• •HVDC (plus or minus 500 to 1,100 kilovolt)

By Installation Type
• •Overhead lines
• •Underground cables
• •Submarine cables

By Component
• •Lines, towers and conductors
• •Power transformers and reactors
• •Switchgear and substations
• •HVDC converter stations
• •Cables and accessories
• •Reactive power compensation

By End User
• •Utilities and transmission system operators
• •Independent transmission developers
• •Merchant interconnector developers
• •Renewable developers and large industrial users