50Hertz and TenneT Accelerate Cable Pulling on 540 km SuedOstLink 525 kV HVDC Underground Transmission Route
Transmission system operators 50Hertz and TenneT have initiated coordinated heavy cable plowing and horizontal directional drilling (HDD) along parallel tren...
50Hertz and TenneT Accelerate Cable Pulling on 540 km SuedOstLink 525 kV HVDC Underground Transmission Route
Transmission system operators 50Hertz and TenneT have initiated coordinated heavy cable plowing and horizontal directional drilling (HDD) along parallel trenches for the 540 km SuedOstLink project, pulling extruded 525 kV DC underground cables with optical thermal monitoring between Wolmirstedt and Landshut to transmit 4 GW of renewable power to southern Germany.
- Publish date: 2026-09-27
- Category: HVDC & Substations
- Original source: 50Hertz Transmission GmbH & TenneT TSO
- Reading time: 5 min
Continuous Underground Cable Laying Across Four Federal States
With all statutory planning approvals secured from the Federal Network Agency (Bundesnetzagentur), construction across the 540 km corridor traversing Saxony-Anhalt, Thuringia, Saxony, and Bavaria has entered its most intensive phase. SuedOstLink (Vorhaben 5 and 5a) utilizes dual bipole systems capable of transferring 4 GW at ±525 kV direct current.
Crews are employing specialized cable-plowing rigs capable of cutting narrow subsoil trenches, embedding thermal bedding sand, and spooling two 525 kV copper conductor cables alongside fiber-optic DTS conduits in a single continuous pass, minimizing topsoil disruption for agricultural landowners.
Overcoming Complex Terrain via Horizontal Directional Drilling (HDD)
To cross sensitive highways, railway trunks, and natural river ecosystems like the Saale and Danube, civil engineering teams executed over 120 trenchless HDD crossings, pulling heavy protective polyethylene conduits through boreholes drilled up to 30 meters beneath the surface.
The extruded 525 kV cross-linked polyethylene (XLPE) cables, supplied by NKT and Prysmian, feature cross-sections up to 2,500 mm² engineered to operate under continuous 90°C thermal loads with zero dielectric degradation.
Synchronization with Wolmirstedt and Isar Converter Stations
Underground cable jointing and sectional sheath bonding are progressing in lockstep with the installation of 525 kV converter transformers at the northern (Wolmirstedt) and southern (Isar) converter hubs.
Commissioning tests will commence in late 2026, leading to full commercial operation in 2027 and bridging Germany’s north-to-south renewable transmission divide.
- RTE France Orders First 400 kV Biodegradable Ester-Filled Autotransformers for Ecodesign Substation Fleet
- Eastern Green Link 1 Breaks Ground on Onshore 2 GW ±525 kV HVDC Converter Stations at Torness and Hawthorn Pit
- EirGrid and SONI Enforce Mandatory 1.0 Hz/s RoCoF Grid Code Standard Across All Island Substation Protection Relays
- KEPCO and HD Hyundai Electric Roll Out 500 kV HVDC Converter Transformers for Yongin Semiconductor Supercluster
- Elia and EIB Finalize €650 Million Green Financing for North Sea Princess Elisabeth 3.5 GW Offshore Energy Island
- GE Vernova and Prolec GE Unveil $375 Million Expansion to Double High-Voltage Transformer Output in North America
- Statnett Energizes 420 kV Aurland-Sogndal Transmission Upgrade Across Challenging Fjord and Alpine Terrain
- TEİAŞ Updates Transmission Substation Capacity Allocations for 3,500 MW Renewable Grid Integration
- TEPCO Power Grid and METI Enforce Binding Substation Transformer Capacity Rules for AI Data Centers
- NSW Approves 1,000 MWh Stoney Creek 8-Hour Grid-Forming BESS Connecting to Transgrid Narrabri Substation
- UK NESO Officially Launches Operations with Winter 2026/27 Outlook and Binding Transmission Queue Milestones
- State Grid China Commissions Shaoxing 1,000 kV UHV Substation Expansion with 3,000 MVA Transformer Banks
- ERCOT Mandates Fast Frequency Response (FFR-2) Rules for Grid-Forming Battery Storage Systems
- Siemens Energy India Wins Major Order for 765 kV Gas-Insulated Substation Package at Khavda Renewable Park
- Saudi Electricity Company Awards Contracts for Four 400 kV GIS Substations to Power NEOM Oxagon Green Hydrogen
- CAISO Board Approves Dynamic Line Rating Deployment on Major Path 15 and Path 26 Transmission Corridors
- ACME Solar and Juniper Green Energize Over 538 MWh of Utility-Scale BESS Across Rajasthan Substations
- POWERGRID Acquires Barmer Transmission to Construct ±800 kV 6,000 MW Desert Solar Evacuation Corridor
- PJM Mandates Strict Frequency and Voltage Ride-Through Standards for 50+ MW AI Data Center Substation Transformers
- AEMO and Powerlink Queensland Energize Dual 250 MVAR Synchronous Condensers for Western Downs Renewable Hub
- ENTSO-E Report Recommends Mandatory Dynamic Transformer Ratings Across 32 European Transmission Operators
- RWE and TotalEnergies Complete Offshore Grid Hookup for 795 MW OranjeWind Project to TenneT Substation
- Terna Completes $150M Divestment of Peruvian Assets to Refocus Capital on Italian Subsea HVDC Corridors
- FERC Suspends PJM’s Emergency Reliability Backstop Auction and Directs Comprehensive Queue Cluster Overhaul
- 50Hertz Awards Ostwind 4 Marine Assurance to ABL for Baltic Sea’s First 2 GW 525 kV HVDC Offshore Grid System
- Chubu Electric and Fuji Electric Unveil Ultra-Low-Loss Amorphous Core Pad-Mounted Transformers for Urban EV Hubs
- Kansai Electric and Mitsubishi Electric Energize Commercial 275 kV SF6-Free Clean Air GIS Substation in Osaka
- Brazil ONS Authorizes Commercial Energization of Xingawa 500 kV Digital Substation and 300 MWh BESS in Bahia
- TenneT Initiates Critical Maasvlakte Dune Drilling for 2 GW IJmuiden Ver Beta and Gamma 525 kV HVDC Landfall
- Hitachi Energy and Enedis Sign $398 Million Framework Agreement for Eco-Efficient Transformers Across France
- Khavda Renewable Mega-Park Energizes 765/400 kV Pooling Substations with 4,500 MVA Transformer Capacity
- Chile’s Kimal-Lo Aguirre 600 kV HVDC Link Surpasses 20% Physical Completion as First 180 Towers Rise in Atacama
- Inelfe Biscay Gulf 5,000 MW HVDC Interconnector Reaches 70% Completion as Converter Stations Enter Electromechanical Phase
- TEİAŞ Launches 400 kV Çanakkale Strait-3 Subsea Cable and Substation Project to Unlock Aegean Wind Power
- KEPCO Accelerates 500 kV East Coast–Seoul HVDC Converter Stations to Power Semiconductor Mega-Clusters
- POWERGRID Augments 765 kV Hub Substations with 1,500 MVA Transformers to Evacuate 20 GW Rajasthan Solar
- Hitachi Energy Completes €30M Bad Honnef Power Transformer Expansion to Ease European Grid Backlog
- Global Substation Transformer Lead Times Extend to 110–160 Weeks Amid Unprecedented Hyperscale AI Demand
- U.S. DOE and Utilities Deploy Grid-Enhancing Technologies and Grid-Forming BESS to Relieve AI Data Center Substation Congestion
- South Africa’s NTCSA Launches 1,164 km 400 kV Independent Transmission Scheme to Unblock Cape Renewable Corridors
- 50Hertz and TenneT Accelerate Cable Pulling on 540 km SuedOstLink 525 kV HVDC Underground Transmission Route
- German TSOs Receive First 525 kV HVDC Converter Transformers at SuedOstLink and SuedLink Terminal Hubs
- CenterPoint Energy and ERCOT Deploy 345/138 kV Mobile Emergency Substation Fleets for Gulf Coast Grid Hardening
- US Grid Operators Advance Interregional Transfer & Transformer Sharing Frameworks under FERC Order 1920
- Japan OCCTO and Chubu Electric Advance Higashi-Shimizu 50 Hz/60 Hz Frequency Converter Expansion to 3,000 MW
- TenneT and Siemens Energy Finalize 525 kV DC Transformer and GIS Architecture for 2 GW North Sea Hubs
- UK National Grid and SSEN Transmission Advance Groundwork on 2 GW Eastern Green Link 2 HVDC Link
- UN and Global Grid Operators Launch Global Grids Accelerator at Climate Week NYC to Unlock 2,500 GW Stalled Renewable Projects
- UK NESO and Ofgem Enforce Strict Transformer and GIS Equipment Milestones to Flush Speculative BESS from 400 kV Transmission Queue
- TEİAŞ Energizes 400/154 kV Autotransformer Expansions Across Marmara Transmission Ring to Safeguard Peak Industrial Load
- NYPA and National Grid Fully Operationalize 100-Mile Smart Path Connect 345 kV Transmission Corridor
- CAISO and Southern California Edison Approve 500/220 kV Whirlwind Substation Transformer Expansion for Mojave Solar
- Eletrobras Furnas Commissions 500 kV Eco-Friendly Digital Substation at Serra da Mesa
- Prysmian and SP Energy Networks Complete 525 kV DC Cable Type-Testing for 2 GW Eastern Green Link 1
- Nordic TSOs Commission Utility-Scale Synchronous Condensers to Reinforce 400 kV Grid Inertia
- Saudi Electricity Company Accelerates 380 kV BSP Substation Super-Cycle for Renewable & Industrial Corridors
- State Grid of China Deploys 300 Mvar Synchronous Condensers at Key UHVDC Converter Substation Hubs
- Marinus Link Granted Australia’s First Offshore Transmission Licence for 1,500 MW Bass Strait HVDC Interconnector
- PPC Rețele Electrice Completes €17M Modernization of Historic Filaret Substation, Expanding Capacity to 200 MVA in Bucharest
- India Launches National Initiative for Indigenous Silicon Carbide (SiC) Power Modules in Ultra-High Voltage VSC-HVDC Transmission
- RTE France and Amprion Commission Synchronized Cross-Border Grid Stability Control for High-Power Interties
- Hitachi Energy Delivers Final Batch of 14 ±500 kV Converter Transformers for 3 GW Saudi-Egypt HVDC Interconnection
- Transgrid and Hitachi Energy Commission Sixth and Final 500 kV Shunt Reactor for HumeLink Substation Backbone
- National Grid UK and NESO Launch Stage 2 Consultation for 400 kV Great Grid Upgrade Corridors Across Midlands and East Anglia
- Elia Installs 23rd Caisson for Princess Elisabeth Energy Island and Closes €1B EIB Green Financing for 220 kV HVAC Hub
- Chile’s Landmark ±600 kV Kimal-Lo Aguirre HVDC Corridor Surpasses 20% Construction Completion in Antofagasta
- Hydro-Québec Awards Major Contract for 735 kV Single-Phase Autotransformers for Hertel and Chamouchouane Substations
- BPA Energizes Upgraded 500 kV Series Capacitor Banks and 1,300 MVA Transformer at Slatt Substation
- Powerlink Queensland Awards $480 Million Substation and Transformer Contracts for CopperString 2032 500 kV Transmission Project
- SSEN Transmission Secures Final Planning Consent for Kintore-Tealing 400 kV Line and Awards £320M Substation Packages
- Astor Enerji Clinches $33.8M U.S. Power Transformer Supply Contract and Unveils Plans for $200M Plant in Kyiv Oblast
- POWERGRID Acquires Barmer HVDC Project to Evacuate 6 GW Solar via ±800 kV Bipole to Maharashtra
- State Grid Brazil Holding Advances Heavy Substation Works for 1,468 km ±800 kV Graça Aranha–Silvânia UHVDC Link
- U.S. DOE Unveils $2.2 Billion in Round 2 GRIP Awards for Substation Transformer Hardening and Dynamic Line Rating
- Hydro One Breaks Ground on Chatham-to-Lakeshore 230 kV Transmission Line and Switching Stations in Southwestern Ontario
- Southern California Edison Commissions 500/115 kV Alberhill Substation to Relieve Riverside County Grid Overload
- Ofgem Approves Eastern Green Link 2 (EGL2): £4.3 Billion 525 kV Subsea HVDC Corridor Between Peterhead and Drax
- TEPCO and Chubu Electric Energize 900 MW Higashi-Shimizu Back-to-Back VSC Frequency Converter Station
- Terna Begins Installation of 1,000 MW VSC HVDC Converter Transformers for the Tyrrhenian Link Eastern Branch
- Regensburg Netz Deploys Schneider Electric GM AirSeT SF6-Free Pure Air GIS to Decarbonize Bavarian Substation Fleet
- SuedLink 525 kV HVDC Supergrid Reaches Structural Milestones at Brunsbüttel and Leingarten Converter Hubs
- WEG Clinches R$660 Million in Substation Contracts for 500 kV Power Transformers and Mobile Grid Units in Brazil
- New York Power Authority and Clean Path NY Order Four 400 MVA 345 kV Phase-Shifting Transformers to Manage Hudson Valley Loop Flows
- ElectraNet Commissions 250 Mvar Synchronous Condenser and 300 MW Grid-Forming Battery at Blyth West Substation
- KEPCO Completes ±500 kV HVDC Bukdangjin-Godeok Transmission Line to Power Samsung Semiconductor Mega-Cluster
- 927 MW Gennaker Offshore Wind Farm Loads Out Substation Topsides for Baltic Sea Sail-Away to 50Hertz Grid Connection
- Envision Energy Energizes 25 MW / 125 MWh Utility BESS at OCP Green Energy Mining Site in Benguerir, Morocco
- Celtic Interconnector Completes Vacuum Oil-Filling for 240-Tonne VSC Converter Transformers at Ballyadam and La Martyre
- Siemens Energy India Energizes First 145 kV SF6-Free "Blue" Circuit Breaker with Clean-Air Vacuum Technology in Goa
- Southwest Power Pool Board Approves $1.8 Billion Transmission Expansion with New 765 kV and 345 kV Corridors Across Texas and Kansas
- SP Energy Networks Commissions Landmark 400 kV SF6-Free Gas-Insulated Substation at Legacy in North Wales
- Statnett and Svenska kraftnät Energize 1,000 MVA 420 kV Phase-Shifting Transformer at Hasle Substation
- RTE Launches Tender for Twelve 600 MVA 400/225 kV Autotransformers for the Dunkirk Industrial Decarbonization Corridor
- Prysmian Certifies 525 kV Extruded Subsea HVDC Cable Systems to 90°C, Elevating Bipole Transmission Capacity to 2.5 GW
- Greenvolt Power Breaks Ground on 600 MW / 2,400 MWh Siedlce BESS in Poland, Central Europe’s Largest Grid Storage Hub
- Invenergy’s Grain Belt Express Finalizes Phase 1 EPC Contracts for ±600 kV HVDC Converter Stations Across Kansas and Missouri
- Vietnam’s EVNNPT Energizes Key 500 kV Circuit 3 Substation Bays and 900 MVA Transformer Banks on North-South Backbone
- Western Power Upgrades 330 kV GIS Substations and Deploys 100 Mvar Variable Reactors to Counter Critical Low Daytime Demand
- Energinet Commissions Revsing 400 kV Substation Expansion with Dual 400 MVA Transformers and 150 Mvar STATCOM
- CIGRE Releases Technical Brochure 992 Establishing Global Standard for VSC-HVDC Station Insulation Coordination
- Eaton Expands North American Power Transformer Capacity with $160 Million Investment to Meet 34.5 kV Data Center Demand
- Eskom Transmission Energizes New 400/132 kV Juno Substation to Unlock 1.2 GW of Wind Power in the Western Cape
- Terna Subsidiary Tamini Wins Landmark Contract for Three 400 kV Autotransformers to Reinforce Danish Power Grid
- Hyperscalers Shift to Direct HVDC Architectures for 150 kW AI Clusters, Cutting Substation Conversion Losses by 15%
- NERC Concludes Formal Ballot on CLO-001/002/003 Standards Mandating Fault Recording on 50+ MW Data Center Transformers
- RWE Approves Final Investment Decision for 400 MW / 1,100 MWh Moerdijk BESS to Anchor Dutch Transmission Grid
- State Grid Corporation of China Energizes 1,901 km ±800 kV Jinshang-Hubei UHVDC Transmission Link
- Eletrobras Furnas Completes 765 kV Transformer Modernization at Foz do Iguaçu Substation for Itaipu Hydropower Delivery
- Origin Energy Commissions $400M 300 MW / 650 MWh Mortlake BESS with Grid-Forming Inverters in Victoria
- H&MV Engineering Establishes North American HQ in Dallas, Unveiling 1,000 High-Voltage Jobs for Data Center Substation Growth
- Eastern Green Link 1 (EGL1) Erects Structural Steel for 2 GW 525 kV Converter Stations at Torness and Murton
- Fraunhofer IEE Study Unveils 150 GW Untapped Solar Capacity via Dynamic Transformer Rating and Substation Storage
- ERCOT Implements Binding NPRR1186 Telemetry and Inverter Frequency Response Protocols for 7+ GW Texas BESS Fleet
- Siemens Energy and Končar Accelerate Croatian Power Transformer Facility as 80% of European Fleet Nears End of Life
- PJM Issues Maximum Generation Alert as September Heatwave and 36 GW Maintenance Outages Challenge Grid Reliability
- Oriana Power Secures 900 MW / 1,800 MWh Grid BESS Mandate from MSEDCL Across Key Substations in Maharashtra
- TenneT and 50Hertz Receive First Heavy 525 kV Converter Transformers for SuedOstLink DC5 Converter Station in Wolmirstedt
- National Grid Energizes 182-Tonne 400 kV Supergrid Transformer at Bicker Fen Substation for Offshore Link
- U.S. House Passes Bipartisan Ratepayer Protection Act (417–3) to Shield Consumers from 100+ MW Data Center Substation Costs
- Spain Expands National Transmission Grid Investment Plan to €17+ Billion Through 2030
- Jupiter Power Secures $1.4 Billion Financing Package for 1,500 MW / 3,600 MWh BESS Portfolio
- Spain Approves Royal Decree Enacting Strategic Capacity Market for Grid Storage and Synchronous Condensers
- 50Hertz Awards Marine Survey Contract for Ostwind 4, the First 525 kV HVDC Offshore Grid System in the German Baltic Sea
- Taipower Energizes Fully Underground 161 kV Gas-Insulated Substation in Tainan to Power 2nm Semiconductor Fabrication
- Hitachi Energy Announces $528 Million Transformer Manufacturing Facility in Gallman, Mississippi
- Hyosung Heavy Industries Validates Domestic ±525 kV VSC Converter Valve and 600 MVA Converter Transformer Architecture
- EirGrid and SONI Winter Outlook 2026–2027 Cites 1,000 MW Grid-Scale Battery Fleets and Synchronous Condensers for Island Reliability
- PGE and Ørsted Complete Dispatch of Four 375 MW Offshore Substation Topsides for 1.5 GW Baltica 2 Offshore Wind Farm
- TenneT, Hitachi Energy, and Larsen & Toubro Finalize Engineering Release for 2 GW LanWin 5 and Nederwiek 3 Platforms
- AEMO Updates Integrated System Plan: Authorizes Early Substation Equipment Procurement for VNI West 500 kV Interconnector
- Türkiye Unveils $108 Billion Energy Roadmap: $28 Billion Dedicated to 28 GW HVDC Corridors and Transmission
- FERC Approves NERC Reliability Standard CIP-014-4 Mandating Enhanced Physical Security for Critical Substation Transformers
- Saudi Electricity Company (SEC) Issues Major Awards for 2.5 GW / 10 GWh Grid-Scale BESS Across Central and Western Substations
- Vikran Engineering Clinches POWERGRID EPC Contract for 400/220 kV Tumkur Substation Expansion and ±300 MVAR STATCOM
- North Sea Offshore Transformer Platforms Energized for 960 MW He Dreiht and 913 MW Borkum Riffgrund 3
- MacLean Power Systems Enters Agreement to Acquire Delta Star Amid Heavy Equipment Shortages
- GE Vernova and LS Electric Launch VSC-HVDC Joint Venture and Unveil 3 GW ±525 kV Valve Architecture
- Global Power Transformer Lead Times Surge to 130+ Weeks as HV Substation Demand Peaks
- 525 kV Subsea HVDC Interconnectors Commissioned to Anchor North Sea Offshore Wind Supergrid
- US DOE Enacts Refined Energy Efficiency Standards for Distribution and Power Transformers
- Grid-Scale Battery Energy Storage Systems (BESS) Successfully Execute Full Substation Black-Start Trials
- Middle East & GCC Accelerate 400 kV Grid Interconnections to Integrate 15+ GW Solar Mega-Parks