Rajasthan Part 5 - LCC Tech Selected for New 6 GW HVDC Scheme
In its latest meeting, National Committee on Transmission (NCT) decided to in for HVDC technology for a major renewable energy evacuation scheme in Rajasthan for which battery energy storage system (BESS) was being evaluated as an option.
On the directions of Central Electricity Authority, Central Transmission Utility of India Ltd (CTUIL) prepared a cost analysis for an HVDC system (both VSC and LCC) and a BESS. Based on this, it was established that an HVDC system (LCC: line-commutated converter) would be the best option as it would have the least capital cost.
As reported by T&D India on May 13, 2025, NCT was evaluating the BESS option as an alternative to an HVDC system meant to transfer 6 GW of solar energy from Barmer in Rajasthan to South Kalamb in Maharashtra.
Based on preliminary estimates, it was then felt that a BESS (6 GW x 4.25 hours) could cost less than an HVDC system, either VSC or LCC.
However, the detailed cost analysis carried out by CTUIL subsequently, established the following cost structure:
The BESS cost was calculated on the basis of several technical assumptions, and the reference cost was taken as Rs.2.80 lakh per MW per month (without viability gap funding) as evinced in a recent tender in Gujarat for a 500 MW (2 hours, 2 cycles per day) BESS.
Accordingly, NCT has approved HVDC-LCC technology for the interstate transmission system (ISTS) scheme that will be developed under the tariff-based competitive bidding (TBCB) route.
This ISTS-TBCB scheme is formally referred to as “Transmission system for evacuation of power from Rajasthan REZ Phase-IV (Part-5: 6 GW) [Barmer Complex] Barmer-II: 6 GW (Solar) (LCC Configuration)” and will have REC Power Development & Consultancy Ltd (RECPDCL) as the bid process coordinator.
With an estimated cost of Rs.24,974 crore, the project implementation period is estimated at 48 months for the first HVDC pole. The second pole will be commissioned six months thereafter (which is 54 months from zero date).
This mega project will have the following key elements:
- A new 400/220kV, 6×500 MVA AIS pooling substation near Barmer (to be known as Barmer-II) with provisions for future expansion
- LILO of both circuits of the existing 400kV Fatehgarh-IV PS to Barmer-I PS line, at Barmer-II pooling substation
- A 400kV double-circuit (quad) line connecting Barmer-I PS and Barmer-II PS
- A new 6,000 MW, ±800kV Barmer-II (HVDC) [LCC] terminal station (4×1500 MW) at a suitable location near Barmer-II PS, Rajasthan
- Establishment of 6,000 MW, ± 800kV South Kalamb (HVDC) [LCC] terminal station (4×1500 MW) at a suitable location near South of Kalamb, Maharashtra
- ±800kV HVDC bipole line (Hexa lapwing) between Barmer-II (HVDC) & South Kalamb (HVDC) with a running length of around 900 km
Besides, suitable augmentation works will be carried out at the upcoming South Kalamb substation that is coming up through a ISTS-TBCB scheme dealing with evacuation from pumped storage projects (PSP) in Maharashtra.
Future modalities of BESS and HVDC
Even as NCT opted for HVDC for the scheme under discussion, it maintained that BESS should be considered as an alternative wherever possible, especially given the huge RE potential in Rajasthan, and the project implementation challenges for HVDC schemes. Accordingly, NCT has directed CTUIL to carry out detailed cost-benefit analysis comparing BESS to HVDC alternatives. The committee also directed CTUIL to work on the modalities for bidding out of BESS projects, under the TBCB framework.
More importantly, NCT has sought specifications from CTUIL to enable technology-agnostic bidding of HVDC systems in future. This would in principle mean that future HVDC schemes would not specify the HVDC technology (VSC or LCC) in the bidding documents.
