IN Brief:
- European transmission operators expect to install approximately 34,000km of HVDC cable and 119 bipolar converter stations by 2035.
- The forecast includes 2,820 transformers, 4,238 SF₆-free GIS bays, and more than 64,000km of advanced overhead conductors.
- Equipment requirements are expected to peak between 2028 and 2032, creating overlapping manufacturing and workforce demands.
ENTSO-E expects European transmission operators to require approximately 34,000km of new high-voltage direct current (HVDC) cable, 119 bipolar converter stations and 2,820 power transformers by 2035, as network expansion and ageing equipment replacement create overlapping demands on manufacturers.
The figures appear in the Transmission Grid Investment and Supply Chain Assessment Report 2026, published on 3 November. The assessment consolidates planned requirements across European transmission networks, covering equipment installations from 2026 to 2035 and identifying the manufacturing capacity, procurement arrangements and specialist skills needed to support them.
Demand across almost every equipment category is expected to peak between 2028 and 2032. Transmission operators face the combined requirements of accommodating renewable generation and changing electricity consumption, replacing infrastructure installed during the 1980s and 1990s, and introducing alternative switchgear technologies as European restrictions on sulphur hexafluoride (SF₆) take effect.
HVDC equipment represents one of the largest areas of planned investment. The assessment identifies more than 22,000km of underground HVDC cable and nearly 12,000km of submarine cable, alongside 119 additional bipolar converter stations. The converter forecast is substantial compared with the 38 stations identified in the existing equipment base.
HVDC transmission is used for long-distance electricity transfer, subsea interconnections and other applications where direct current offers technical advantages over conventional alternating current arrangements. Converter stations provide the interface between AC networks and DC transmission circuits, controlling electrical conversion and the transfer of power between connected systems.
Manufacturing requirements extend across converter valves, power electronics, transformers, cooling systems, controls and high-voltage insulation equipment. Cable production introduces separate constraints involving conductor materials, insulation systems, accessories and testing facilities, while completed cable systems must be transported and installed within the limits established by their mechanical and electrical design.
Submarine projects add specialist installation vessels, offshore handling equipment and seabed conditions to the delivery process. Underground routes require civil construction, cable pulling and jointing operations coordinated with the availability of manufactured cable lengths. These activities must be sequenced with converter station completion and system commissioning before a connection can enter service.
ENTSO-E also forecasts 2,820 additional power transformers, compared with an existing fleet of 5,649 units. Transformers provide the voltage conversion required between generating facilities, transmission circuits and downstream networks, with their design determined by rated power, voltage, insulation requirements, cooling arrangements and operating conditions.
Large transformer production depends on specialised electrical steel, conductors, insulation systems and manufacturing processes. Factory testing is particularly important because equipment must withstand electrical, thermal and mechanical stresses over an extended operating life. Transport and installation can introduce further constraints where transformer dimensions and mass require specialised handling or restricted routes.
Switchgear requirements are changing alongside network expansion. Operators forecast 4,238 bays of SF₆-free gas-insulated switchgear, while planned additions also include 10,819 SF₆ air-insulated circuit breakers and 2,884 conventional SF₆ gas-insulated switchgear bays during the transition period.
The coexistence of conventional and alternative equipment reflects different procurement, replacement and regulatory requirements across the network fleet. SF₆-free technologies must satisfy the relevant insulation, switching and fault interruption duties, with equipment selection influenced by voltage level, installation space, maintenance arrangements and applicable restrictions.
Manufacturers will consequently need to support several equipment technologies while developing production capability for alternatives. Transmission operators must integrate new switchgear into operating substations, where protection coordination, control interfaces and maintenance practices may differ from those associated with established equipment.
Existing overhead transmission infrastructure is another major component of the forecast. ENTSO-E identifies more than 64,000km of high-temperature low-sag conductors, which can operate at higher temperatures while limiting the conductor sag that occurs as electrical loading increases.
Reconductoring can provide additional transfer capacity on suitable existing routes, although the achievable rating depends on supporting structures, electrical clearances, terminals and other network equipment. Installation also requires outage planning and methods compatible with the condition and configuration of the existing overhead line.
Dynamic line rating offers a complementary approach by using environmental and operating measurements to assess how much current a transmission line can safely carry under prevailing conditions. Wind speed, ambient temperature and conductor temperature affect the thermal performance of overhead circuits, allowing their available capacity to vary rather than remain fixed at a conservative static value.
Realising that capacity requires monitoring equipment, communications and integration with transmission control systems. The line’s permissible operating limits must remain consistent with its physical clearances and the ratings of connected equipment, so improved monitoring does not remove the need for engineering assessment of the complete circuit.
Reactive power compensation is also expected to expand substantially. ENTSO-E forecasts growth of 482% in static synchronous compensators (STATCOMs) rated above 150MVA. These systems use power electronic converters to control reactive current and support voltage regulation as electricity flows and generation patterns change.
STATCOM installations require converter equipment, cooling, transformers, protection and controls coordinated with the transmission network. Their increasing use adds another category of specialised manufacturing and commissioning demand alongside cables, transformers and switchgear.
The assessment recommends that equipment manufacturers align capacity expansion with the forecast requirements and communicate demand expectations to second- and third-tier suppliers. ENTSO-E also calls for stronger cooperation among transmission operators on technical specifications and long-term procurement planning, together with measures to address shortages of suitably qualified personnel.
The association represents 40 transmission system operators across 36 countries. Its projections describe planned installations rather than purchase orders already awarded, and delivery remains dependent on individual network investment and procurement programmes. The concentration of requirements between 2028 and 2032 nevertheless establishes a common planning horizon for manufacturers, engineering contractors and transmission operators preparing Europe’s next phase of grid investment.
