Kansai Electric and Mitsubishi Electric Energize Commercial 275 kV SF6-Free Clean Air GIS Substation in Osaka
The Kansai Electric Power Company and Mitsubishi Electric Corporation have energized Japan’s first commercial 275 kV gas-insulated substation (GIS) operating...
Kansai Electric and Mitsubishi Electric Energize Commercial 275 kV SF6-Free Clean Air GIS Substation in Osaka
The Kansai Electric Power Company and Mitsubishi Electric Corporation have energized Japan’s first commercial 275 kV gas-insulated substation (GIS) operating entirely without sulfur hexafluoride (SF6), utilizing dry clean air dielectric insulation and high-voltage vacuum circuit breakers to eliminate potent greenhouse gases from urban power infrastructure.
- Publish date: 2026-09-28
- Category: Transformers & Grid
- Original source: Kansai Electric Power & Mitsubishi Electric Corporation
- Reading time: 5 min
Eliminating SF6 from High-Voltage Urban Transmission Substations
Sulfur hexafluoride (SF6) possesses a global warming potential 24,300 times greater than CO2, prompting global grid operators to seek zero-GWP switchgear alternatives. On September 28, 2026, Kansai Electric energized a flagship 275 kV substation in the Osaka metropolitan area engineered by Mitsubishi Electric.
The facility replaces traditional SF6 insulation with pressurized natural clean air (a precision dry mixture of 80% nitrogen and 20% oxygen), ensuring zero toxic decomposition byproducts and zero greenhouse gas impact throughout its 40-year design lifetime.
High-Capacity 275 kV Vacuum Circuit Breaker (VCB) Breakthrough
Because clean air lacks the intense arc-quenching capability of SF6, Mitsubishi Electric developed an advanced high-power vacuum interrupter bottle capable of breaking short-circuit currents up to 50 kA at 275 kV.
The substation connects two 300 MVA 275/77 kV low-noise power transformers, feeding critical urban rail networks and commercial districts with verified zero-emission high-voltage switching reliability.
Setting the Standard for Asia-Pacific Substation Decarbonization
Kansai Electric announced that the success of the Osaka installation establishes the engineering baseline for retiring legacy SF6 switchgear across its transmission territory, accelerating Japan’s 2050 carbon-neutrality commitments.
- 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