Energy Efficiency Services Limited (EESL), a joint venture of Public Sector Undertakings under the Ministry of Power, has released a tender for the development of a 120 kW / 6-hour Battery Energy Storage System (BESS) at New Melli, Sikkim. The project involves turnkey design, supply, testing, installation, and commissioning, fully funded through domestic resources.
Bids are invited via a single-stage, two-envelope system, with technical and financial proposals submitted separately. Only technically qualified bidders will have their financial proposals evaluated.
Tender Overview
- Tender Title: Development of 120 kW / 6-hour BESS at New Melli, Sikkim
- Total BESS Capacity: 120 kW with 6-hour storage
- Technology: Lithium-Ion Battery Energy Storage System
- Bidding Route: EPC, Single-Stage Two-Envelope System
- Issuing Authority: Energy Efficiency Services Limited (EESL)
Project Location
- Location: New Melli, Sikkim
- Pre-Bid Meeting Venue: EESL Corporate Office, 1st to 4th Floor, IKON Tower, Film City, Sector 16A, Noida, Uttar Pradesh – 201301 (Online participation available)
Technical Specifications
- System Architecture: Turnkey EPC delivery including design, engineering, supply, installation, testing, and commissioning
Key Components:
- Battery Management System (BMS)
- Energy Management System (EMS)
- Power Conversion System (PCS)
- Civil and electrical works
- Auxiliary systems and fire safety
Performance Requirements:
- 5-year warranty for battery components
- 12-month (or 18-month from delivery) warranty for Balance of System (BoS) components
- Completion within 3 months from Letter of Award (LOA)
Key Dates & Bid Conditions
- Pre-Bid Meeting: 19 December 2025 at 11:00 AM IST
- Bid Submission Deadline: 30 December 2025 at 11:00 AM IST (both online & hard copy)
- Opening of Envelope-1 (Technical Bid): 30 December 2025 at 11:30 AM IST
- Opening of Envelope-2 (Financial Bid): After technical evaluation
- Tender Fee: ₹20,000 (non-refundable)
- Bid Security / EMD: ₹500,000
Eligibility & Requirements
- Open to domestic EPC contractors
- Contractors must meet technical and financial qualification criteria
- Turnkey delivery capability required, including installation, testing, commissioning, and warranty obligations
Project Significance
The New Melli BESS project strengthens India’s energy storage infrastructure in strategic regions like Sikkim, enhancing grid stability and reliability. It reflects EESL’s commitment to advanced energy storage solutions and sustainable energy development.
| Capacity | 120 kW / 6h |
| Location | New Melli, Sikkim |
| Last Date | 30/12/2025 |





