Green Energy Open Access (GEOA) is transforming how industries in India procure electricity. With supportive policies from the Ministry of Power and regulatory oversight by the Central Electricity Regulatory Commission, large commercial and industrial consumers are increasingly sourcing renewable power from high-resource states like Gujarat. West Bengal, with its steel, chemicals, and engineering clusters, is emerging as a key destination for inter-state renewable procurement.
This blog explains the step-by-step calculation of Green Energy Open Access charges for a consumer in West Bengal sourcing solar power from Gujarat.
Inter-State Green Energy Open Access Cost Calculator (Gujarat to West Bengal)
• ISTS waiver assumed for eligible renewable projects.
• West Bengal open access charges vary based on voltage and consumer category.
• This calculator is only for representation and estimation purposes.
Understanding the Scenario
Let us assume the following:
- Source State: Gujarat
- Consumer State: West Bengal
- Connected Load: 100 MW
- Monthly Energy Procurement: 3,00,000 units
- PPA Tariff: ₹3.40 per kWh
- Renewable Source: Solar
- Consumer Category: Commercial and Industrial
- Procurement Model: Third-party Green Open Access
Why Gujarat to West Bengal Renewable Procurement is Increasing
West Bengal has several energy-intensive sectors such as:
- Steel and metal processing
- Petrochemicals
- Engineering and manufacturing
- Cement and construction
- Port and logistics operations
These industries are adopting renewable energy to:
- Reduce electricity costs
- Achieve sustainability goals
- Improve ESG compliance
- Secure long-term price stability.
Step 1: Power Purchase Agreement (PPA) Cost
The PPA tariff forms the base cost.
In this case:
- ₹3.40 per kWh
- Monthly scheduled energy = 3,00,000 units.
Step 2: Inter-State Transmission System (ISTS) Charges
The Government of India offers ISTS charge waivers for eligible renewable projects.
If the Gujarat project qualifies:
- ISTS charges = Zero.
If not:
- Typical range = ₹0.10 to ₹0.50 per kWh.
Step 3: Inter-State Transmission Losses
Losses occur during long-distance transmission through the national grid coordinated by Power System Operation Corporation.
Assuming:
- ISTS loss = 3%.
Delivered energy:
- 3,00,000 × (1 – 0.03)
- Delivered = 2,91,000 units.
Step 4: State Transmission Charges in West Bengal
After reaching the state, electricity flows through the West Bengal network.
Typical range:
- ₹0.20 to ₹0.50 per kWh.
Assuming:
- ₹0.28 per kWh.
Step 5: Wheeling Charges
Charges for distribution network usage.
Typical range:
- ₹0.40 to ₹1.00 per kWh.
Assuming:
- ₹0.65 per kWh.
Step 6: Cross Subsidy Surcharge (CSS)
CSS compensates the DISCOM when consumers opt for open access.
Typical range in West Bengal:
- ₹1.7 to ₹2.3 per kWh.
Assuming:
- ₹1.90 per kWh.
Step 7: Additional Surcharge
Applied to recover stranded infrastructure costs.
Typical range:
- ₹0.30 to ₹0.80 per kWh.
Assuming:
- ₹0.45 per kWh.
Step 8: Scheduling and System Operation Charges
Charges for scheduling and grid balancing.
Assuming:
- ₹0.05 per kWh.
Step 9: Banking Charges (if applicable)
This example assumes no banking.
Important Disclaimer
This calculation example is only for representation and educational purposes. Actual Green Energy Open Access charges vary depending on regulatory approvals, consumer category, voltage level, project eligibility, and periodic tariff revisions.
Step-by-Step Cost Calculation Example
Delivered Energy
Scheduled energy = 3,00,000 units
After ISTS loss of 3%:
Delivered energy = 2,91,000 units.
Landed Cost Components
| Component | Cost (₹/kWh) |
|---|---|
| PPA Tariff | 3.40 |
| West Bengal Transmission | 0.28 |
| Wheeling | 0.65 |
| CSS | 1.90 |
| Additional Surcharge | 0.45 |
| Scheduling & SLDC | 0.05 |
Total Landed Cost = ₹6.73 per kWh.
Monthly Power Cost
2,91,000 × 6.73
= ₹19.59 lakh approximately.
Step 10: Compare with West Bengal DISCOM Tariff
If industrial tariffs in West Bengal are:
- ₹8 to ₹10 per kWh → Significant savings.
- ₹7 per kWh → Captive or hybrid renewable procurement may offer better economics.
Key Strategies to Reduce Costs
- Captive renewable structure
- Solar and wind hybrid
- Storage integration
- High voltage connectivity
- Long-term corporate PPAs
- Time-of-day optimization
- Load aggregation
- ISTS waiver eligibility
- Policy incentives
- Energy management.
Future Outlook for Renewable Procurement in West Bengal
The state is expected to see strong renewable adoption due to:
- Industrial decarbonization
- Corporate sustainability goals
- Flexible procurement through exchanges such as Indian Energy Exchange
- Hybrid and round-the-clock renewable energy.
Conclusion
For a 100 MW connected load consumer in West Bengal, sourcing solar power from Gujarat at ₹3.40 per kWh offers significant economic and sustainability benefits. With favorable policies and ISTS waivers, inter-state Green Energy Open Access is poised to play a major role in the state’s energy transition.
