Maharashtra Electricity Regulatory Commission (MERC), in a recent suo moto order, has proposed the creation of a committee for close monitoring of upcoming projects aimed at strengthening the Mumbai power transmission network.
Following the Mumbai grid failure of October 12, 2020, several projects to improve Mumbai power transmission network have been proposed or revived. These mainly include the 400kV Kharghar-Vikhroli transmission project, the Kudus-Aarey HVDC project and associated transmission schemes.
MERC has ruled that the proposed monitoring committee shall not only monitor the progress of implementation of identified transmission schemes but also monitor other action points as per recommendations of High Level Committee (HLC) and highlight deviations from approved implementation plan submitted by implementing entity. [The HLC is discussed ahead in the story.]
Details on the proposed committee, such as composition, terms of reference for deliverables, reporting requirements, etc, will be communicated by MERC through a separate notification, the commission’s order said.
The state regulator has also ruled that scheme implementing agencies, Mahatransco (the state transmission utility), and state load dispatch centre (SLDC) shall extend the necessary co-operation to the Monitoring Committee in terms of the information, progress of the scheme, activity plan etc. to assess the correct progress of the schemes being executed.
Kharghar-Vikhroli line
The 400kV Kharghar-Vikhroli double-circuit line is being developed by Kharghar Vikhroli Transmission Pvt Ltd (KVTPL), a wholly-owned subsidiary of Adani Transmission Ltd. The line spanning 74 ckm and with a power transmission capacity of 1,500 MVA is estimated to cost Rs.1,890 crore.
On January 23, 2021, MERC granted the transmission licence to KVTPL to develop the Kharghar-Vikhroli transmission line under the build, own, operate and maintain (BOOM) modality for e period of 35 years. The project was awarded under the TBCB modality. The completion date envisaged in the transmission licence is 30 months from the “effective date”, which works out to March 12, 2022.
By current thinking, this line is expected to commission by December 2022.
Kudus-Aarey HVDC Line
MERC has also issued license to Adani Electricity Mumbai Infra Ltd (AEMIL), a newly-formed subsidiary of Adani Electricity Mumbai Ltd (AEML), for construction of a 1,000-mw HVDC transmission link from Kudus in Maharashtra to Aarey in Mumbai, with an approximate length of 80 km. AEML, in turn a subsidiary of ATL, is a power distribution licensee for the Mumbai area.
The MERC licence that came into force on March 21, 2021 authorizes AEMIL (the transmission licensee) to build, own, operate and maintain the 1,000-mw HVDC link, for a period of 25 years. The project cost is likely to cost Rs.7,000 crore.
The biggest component of the transmission system will be ±320kV underground HVDC link between Aarey and Kudus, running 80 km. There will also be nine bays of 220kV and 14 bays of 400kV, apart from small lines connecting the Aarey (Adani Group) and Kudus (MSETCL) substations to the main HVDC line. The HVDC system is envisaged for completion in 48 months.
The HLC thus emphasized that development of a 400kV network within Mumbai was of utmost importance.
High Level Committee
Shortly after the Mumbai grid collapse on October 12, 2020, MERC appointed a high-level committee (HLC) for doing a root-cause analysis of the grid failure. Incidentally, this HLC presented its preliminary findings on November 8, 2020 and presented its final report (revised) on May 11, 2021.
The detailed report of the HLC features a host of short-, medium- and long-term measures to forestall such grid failures in future. The committee demanded an immediate review of the existing Mumbai islanding scheme, and the load trimming schemes. Some of the major recommendations insofar as transmission system planning in Mumbai was concerned, were as follows:
- Implementation of 400/220kV Vikhroli substation and associated transmission lines
- Enhancing transmission capacity for feeding power into Mumbai Metropolitan Region (MMR) through HVDC lines
- Augmentation of capacity of existing transmission corridor
The HLC also pointed out that the transmission network of the existing two licensees – Tata Power (TPC-T) and Adani Electricity Mumbai Ltd (AEML) – were of 100kV and 220kV. The committee observed that there was no 400kV level transmission network within Mumbai. The HLC thus emphasized that development of a 400kV network within Mumbai was of utmost importance.
(Featured photograph shows power transmission towers and lines in Mumbai’s suburban area.)
