MERC approves BEST's procurement of 220 MW solar + 110 MW/440 MWh ESS from SECI at Rs 2.86-2.87/kWh plus 7 paise trading margin for 25 years
Petition of Brihanmumbai Electric Supply and Transport Undertaking for seeking approval for procurement of 220 MW Solar Power with 110 MW/440 MWh Energy Storage System (ESS) under ISTS connected Tranche - XX Scheme from SECI on long term basis and to consider such power towards meeting the RPO of BEST under Section 86(1) (b) of Electricity Act 2003 and Regulation 21.1 of MERC (Multi Year Tariff) Regulations, 2024. And Interlocutory Application of Brihanmumbai Electric Supply and Transport Undertaking seeking urgent hearing in Case No. 76 of 2026.
BEST sought MERC approval under Section 86(1)(b) of EA 2003 to procure 220 MW solar power coupled with 110 MW/440 MWh ESS from SECI under its Tranche-XX FDRE scheme, at a competitively discovered tariff, to count towards its RPO/ESO compliance and Resource Adequacy Plan. BEST also filed an IA seeking urgent hearing since delay beyond 27 October 2026 (12 months from LoA issuance) would trigger automatic cancellation of project allocation per SECI's RfS Clause 42.4.
- Approved BEST's procurement of 220 MW solar + 110 MW/440 MWh ESS from SECI at Rs 2.86-2.87/kWh plus Rs 0.07/kWh trading margin, fixed for 25 years from SCSD
- Approved execution of the Power Sale Agreement (PSA) between BEST and SECI on terms placed on record
- Approved counting of procured power towards BEST's RPO and Energy Storage Obligation (ESO) compliance
- Held that since CERC already adopted the tariff under Section 63 on 24 March 2026, MERC cannot re-determine tariff and only examines procurement prudence
- Allowed trading margin of Rs 0.07/kWh subject to CERC's conditions (limited to Rs 0.02/kWh if SECI fails to provide escrow/LC to generators)
- Directed STU and MSLDC to process connectivity, Long-Term Access and scheduling applications per applicable regulations pending new BESS-specific regulations
- BEST and SECI to execute PSA on approved terms; PPA to be executed with selected SPDs before 27 October 2026 deadline to avoid cancellation
- Selected SPDs (LC Infra, GH2 Solar, Navayuga Green Energy) to proceed with land acquisition and transmission connectivity applications
- STU/MSETCL and MSLDC to process connectivity, Long-Term Access and scheduling applications per current framework and Maharashtra RE & Energy Storage Policy 2025-26 to 2035-36
- MEDA/MSETCL/MSEDCL/MSLDC to modify Single Window Portal to incorporate ESS components
- MERC to notify dedicated BESS operational regulations (scheduling, charging/discharging, deviation settlement, metering) — pending till then existing framework applies
- Trading margin reconciliation contingent on SECI providing escrow/LC arrangement to generators; GST-linked reverse Change in Law tariff reduction (10-12 paise/kWh) to be reconciled separately
- • Validates SECI's intermediary-procurer FDRE bidding route as a viable, MERC-endorsed model for discoms to secure low-cost (~Rs 2.86-2.94/kWh all-in) firm RE with storage, relevant for C&I open-access/group captive comparisons
- • Confirms State Commissions cannot re-litigate CERC-adopted Section 63 tariffs, streamlining approval timelines for buyers relying on SECI/central bidding schemes
- • STU-connected (non-ISTS) projects avoid ISTS charges/losses, improving landed cost — a signal for developers to prioritize intra-state connectivity for Maharashtra offtake
- • Absence of finalized BESS operational regulations (scheduling, deviation settlement, metering) remains a live risk for storage-linked RE/open-access transactions until MERC notifies dedicated rules
This order confirms MERC's comfort with SECI-intermediated FDRE bidding as a fast, cost-effective RPO/ESO compliance route, and reinforces that once CERC adopts a Section 63 tariff, State Commissions will largely rubber-stamp procurement prudence rather than re-open tariffs. For developers, the binding 27 Oct 2026 PPA deadline and pending BESS operational regulations are the real execution risks — connectivity and scheduling clarity from STU/MSLDC should be tracked closely before financial closure.
Growthifye does not take responsibility for the accuracy of this information. Values are compiled from tariff orders published on the websites of State Electricity Regulatory Commissions and distribution licensees (plus CEA / MoP / Grid-India), parsed automatically and shown with their source. Always verify against the signed order before any commercial decision. This one-pager is a Vidura-assisted summary of the official order; the signed order prevails.