Executive Summary
Green Energy Corridors (GEC) are dedicated transmission infrastructure projects to evacuate renewable energy from generation zones to load centers. Understanding GEC framework is critical for renewable energy developers, transmission planners, and policy analysts:
- Objective: Evacuate 175 GW renewable capacity (now 500 GW by 2030)
- Phases: GEC-I (9,700 MW), GEC-II (20,000 MW), Interstate corridors (66,000 MW)
- Technology: 765 kV, 400 kV AC, HVDC for long-distance
- Funding: World Bank, KfW, ADB, GoI budgetary support
- Regulatory Framework: CEA transmission planning, CERC tariff
This guide examines GEC planning, implementation, technological solutions, and regulatory aspects.
1. Statutory Framework
Electricity Act, 2003
| Section |
Provision |
| Section 14 |
CTU to plan and coordinate interstate transmission |
| Section 73 |
National Policy on electricity |
| Section 79(1)(b) |
CERC to regulate interstate transmission |
National Electricity Plan (CEA)
| Plan Period |
RE Integration Target |
Transmission Requirement |
| 2017-2022 |
175 GW RE |
25,000 ckt-km |
| 2022-2027 |
280 GW RE |
50,000 ckt-km |
| 2027-2032 |
500 GW RE |
1,00,000 ckt-km |
Green Energy Corridor Scheme
| Scheme |
Year |
Coverage |
Capacity |
| GEC Phase-I |
2015 |
8 states |
9,700 MW |
| GEC Phase-II |
2021 |
13 states |
20,000 MW |
| Interstate GEC |
2020-2025 |
Pan-India |
66,000 MW |
2. Renewable Energy Zones (REZ) and Evacuation Needs
Major RE Zones in India
| Zone |
States |
RE Potential |
Dominant Source |
Transmission Challenge |
| Rajasthan Solar Zone |
Rajasthan (Jaisalmer, Jodhpur) |
50 GW |
Solar |
Long-distance to load centers (1,500 km) |
| Gujarat RE Zone |
Gujarat (Kutch) |
30 GW |
Wind, Solar, Offshore Wind |
Evacuation to Western/Northern grid |
| Tamil Nadu Wind Zone |
Tamil Nadu (coastal) |
20 GW |
Wind, Solar |
Intra-state congestion |
| Karnataka RE Zone |
Karnataka |
15 GW |
Solar, Wind |
Southern grid congestion |
| Ladakh Solar Zone |
Ladakh |
13 GW |
Solar |
Ultra-long HVDC (2,000 km) |
| Andhra Pradesh |
Andhra Pradesh |
15 GW |
Solar, Wind |
Evacuation to Southern/Eastern grid |
3. Green Energy Corridor Phase-I (GEC-I)
GEC-I Overview
| Aspect |
Details |
| Launch |
2015 |
| States covered |
Tamil Nadu, Rajasthan, Karnataka, Gujarat, Maharashtra, Andhra Pradesh, Himachal Pradesh, Madhya Pradesh |
| Capacity |
9,700 MW evacuation |
| Funding |
KfW Germany, GoI |
| Total cost |
Rs 4,056 crore |
| Status |
90% completed (2023) |
GEC-I State-wise Allocation
| State |
Transmission Scheme |
Capacity (MW) |
Status |
| Tamil Nadu |
Pooling stations, 230 kV lines |
3,000 |
Operational |
| Rajasthan |
400 kV transmission network |
2,500 |
Operational |
| Karnataka |
220 kV/400 kV evacuation |
1,500 |
Operational |
| Gujarat |
220 kV network augmentation |
1,200 |
Operational |
| Maharashtra |
400 kV lines |
800 |
Operational |
| Others |
Various schemes |
700 |
Ongoing |
4. Green Energy Corridor Phase-II (GEC-II)
GEC-II Overview
| Aspect |
Details |
| Launch |
2021 |
| States covered |
13 states (includes GEC-I states + new) |
| Capacity |
20,000 MW evacuation |
| Funding |
World Bank, ADB, GoI |
| Total cost |
Rs 12,000 crore |
| Timeline |
2021-2026 |
GEC-II Focus Areas
| Component |
Investment |
Objective |
| Intra-state transmission |
Rs 8,000 crore |
Last-mile connectivity |
| Interstate transmission |
Rs 3,000 crore |
Inter-regional evacuation |
| SLDC upgradation |
Rs 500 crore |
RE forecasting, scheduling |
| Grid balancing |
Rs 500 crore |
Frequency regulation, reserves |
5. Interstate Green Energy Corridors
ISTS for RE Zones
| Corridor |
From |
To |
Technology |
Capacity (MW) |
Status |
| Rajasthan-Delhi/Haryana |
Jaisalmer, Bikaner |
Delhi, Haryana |
765 kV AC, ±800 kV HVDC |
20,000 |
Under construction |
| Ladakh-Punjab |
Ladakh |
Punjab |
±800 kV HVDC (2,000 km) |
13,000 |
Planned (2026-2030) |
| Gujarat-Maharashtra |
Kutch |
Mumbai |
765 kV AC |
10,000 |
Under construction |
| Tamil Nadu-Kerala |
Tamil Nadu |
Kerala |
400 kV AC |
3,000 |
Operational |
| Offshore Wind Corridors |
Gujarat coast |
Gujarat grid |
Offshore AC/HVDC |
5,000 |
Planned |
6. Technological Solutions for RE Evacuation
High Voltage AC (HVAC)
| Voltage Level |
Typical Distance |
Power Transfer Capacity |
Use Case |
| 765 kV |
Up to 500 km |
5,000-7,000 MW |
Bulk power, medium distance |
| 400 kV |
Up to 300 km |
1,500-2,500 MW |
Regional interconnections |
| 220 kV |
Up to 150 km |
500-1,000 MW |
Intra-state, pooling stations |
High Voltage Direct Current (HVDC)
| Type |
Distance |
Advantages |
RE Use Case |
| ±800 kV HVDC |
1,000-3,000 km |
Lower losses, no distance limit |
Ladakh-Punjab, Rajasthan-Northern grid |
| ±500 kV HVDC |
500-1,500 km |
Asynchronous grid connection |
Gujarat-Maharashtra |
| Multi-terminal HVDC |
Variable |
Connect multiple RE sources |
Offshore wind clusters |
Flexible AC Transmission Systems (FACTS)
| Device |
Function |
RE Benefit |
| STATCOM |
Reactive power support |
Voltage stability for wind farms |
| SVC (Static Var Compensator) |
Dynamic voltage control |
Solar plant grid support |
| TCSC (Thyristor Controlled Series Capacitor) |
Power flow control |
Optimal power routing |
7. Pooling Substations for RE
Pooling Station Framework
| Aspect |
Details |
| Purpose |
Aggregate multiple RE generators at common point |
| Typical capacity |
500-2,000 MW |
| Voltage |
220 kV or 400 kV |
| Cost sharing |
Pro-rata among connected generators |
| Developer |
CTU, STU, or generator consortium |
Major Pooling Stations
| Location |
State |
Aggregated Capacity (MW) |
Technology |
| Bhadla |
Rajasthan |
10,000 |
Solar |
| Pavagada |
Karnataka |
2,000 |
Solar |
| Rewa |
Madhya Pradesh |
750 |
Solar (Ultra Mega Solar Park) |
| Charanka |
Gujarat |
600 |
Solar |
8. Grid Integration Challenges for RE
Technical Challenges
| Challenge |
RE Impact |
Solution |
| Intermittency |
Solar/wind generation varies |
Forecasting, scheduling, balancing reserves |
| Reverse power flow |
Distribution system designed for one-way flow |
Grid upgradation, smart inverters |
| Voltage fluctuations |
Rapid cloud cover, wind gusts |
FACTS devices, reactive power management |
| Frequency stability |
Low inertia (inverter-based RE) |
Synthetic inertia, battery storage |
Regulatory Solutions
| Solution |
Mechanism |
| Must-run status |
RE cannot be backed down (except grid security) |
| Forecasting and scheduling |
Mandatory day-ahead + intra-day forecasts |
| Deviation settlement |
Penalty for >15% deviation |
| Renewable Energy Management Centers (REMC) |
Centralized RE forecasting and dispatch |
9. Funding and Financing GEC
Multilateral Funding
| Source |
Amount |
GEC Phase |
| KfW Germany |
€500 million |
GEC-I |
| World Bank |
$1.5 billion |
GEC-II |
| ADB |
$500 million |
GEC-II |
| GoI budgetary support |
Variable |
Both phases |
Tariff Recovery (CERC Regulations)
| Cost Component |
Recovery Mechanism |
| Transmission charges |
Rs/MW/month from RE generators |
| ISTS charges |
Shared among LTA holders |
| GEC-specific costs |
Pooled and allocated |
10. Renewable Energy Management Centers (REMC)
REMC Functions
| Function |
Scope |
| Forecasting |
Day-ahead, intra-day wind/solar forecasts |
| Scheduling |
Optimize RE dispatch |
| Real-time monitoring |
SCADA for RE plants |
| Deviation management |
Minimize DSM charges |
State REMCs
| State |
REMC Status |
Aggregated RE (MW) |
| Tamil Nadu |
Operational |
15,000 |
| Rajasthan |
Operational |
18,000 |
| Karnataka |
Operational |
14,000 |
| Gujarat |
Operational |
13,000 |
11. Battery Energy Storage Systems (BESS) for Grid Stability
BESS Integration with GEC
| Aspect |
Specification |
| Purpose |
Store excess RE, discharge during deficit |
| Typical size |
100-500 MWh |
| Location |
Co-located with RE plants or substations |
| Technology |
Lithium-ion, flow batteries |
Pilot Projects
| Project |
Capacity (MW/MWh) |
Location |
Status |
| SECI BESS Tender |
1,000 MW / 2,000 MWh |
Pan-India |
Tendering |
| Rajasthan BESS |
50 MW / 100 MWh |
Jaisalmer |
Under construction |
| Karnataka Pilot |
10 MW / 10 MWh |
Raichur |
Operational |
12. Compliance Checklist for RE Evacuation
For RE Generators Seeking GEC Connectivity
For Transmission Planners
13. Key Takeaways for Practitioners
GEC is Critical for 500 GW Target: Without transmission corridors, RE generation will curtail—prioritize evacuation planning.
HVDC for Long-Distance: Ladakh, Rajasthan RE zones need 1,500-2,000 km transmission—HVDC is cost-effective.
Pooling Substations Save Costs: Shared evacuation infrastructure reduces per-MW cost—participate in CTU pooling schemes.
Forecasting is Mandatory: All RE plants must forecast via REMC/QCA—invest in forecasting systems early.
BESS Will Be Essential: As RE penetration increases, storage mandates likely—plan for co-located BESS.
GEC-II Funding Available: World Bank, ADB grants reduce state burden—leverage for intra-state transmission.
Must-Run Status Protects RE: Grid Code prioritizes RE dispatch—ensures evacuation unless grid security issue.
Conclusion
Green Energy Corridors are the lifeline for India's renewable energy ambitions, enabling seamless evacuation of solar and wind power from resource-rich zones to demand centers. The multi-phase GEC program (GEC-I, GEC-II, Interstate corridors) supported by multilateral funding and advanced technologies (765 kV, HVDC, FACTS) positions India to integrate 500 GW renewable capacity by 2030. Practitioners must navigate transmission planning, LTA procedures, Grid Code compliance, and REMC coordination to ensure RE projects achieve commercial operation without evacuation bottlenecks. As battery storage and grid modernization advance, GEC will evolve into a fully flexible, RE-centric transmission backbone.
