Battery energy storage being evaluated as alternative to HVDC link in Rajasthan
- May 13, 2025
The option of using battery energy storage system (BESS) as an alternative to an HVDC-based transmission system is being evaluated in Rajasthan.
This discussion came about during the latest meeting of the National Committee on Transmission (NCT) regarding excessive solar generation in Rajasthan.
Rajasthan will need evacuation infrastructure for 75 GW of RE capacity out of which 13 GW is located in Fatehgarh (8 GW) and Barmer (5 GW). Several ISTS schemes are already in implementation to provide connectivity to RE generators in the Fatehgarh/Barmer complex.
To fulfill growing ISTS connectivity applications at the said complex, it was proposed that an HVDC link be established between the Barmer-II pooling station and South Kalamb pooling station in Maharashtra. Incidentally, the South Kalamb substation is coming through a separate ISTS-TBCB scheme dealing with evacuation from pumped storage projects (PSP) in Maharashtra.
Central Transmission Utility of India Ltd (CTUIL) has estimated that an HVDC link from Bamer-II to South Kalamb would cost Rs.25,261 crore if LCC technology were used. In the case of VSC technology, the cost would be around Rs.34,814 crore.
This HVDC link would transmit solar generation from the Fatehgarh/Barmer complex to Maharashtra for onward transmission to load centres in Maharashtra using downstream networks already planned.
This HVDC link would help honour 6 GW of connectivity applications received/granted at the Barmer-III Pooling Station (PS). Connectivity applications worth 9 GW have already been granted for RE generators in the Fatehgarh/Barmer complex at Barmer-I PS, Fatehgarh-IV PS and Barmer-II PS.
The BESS alternative
The proposal to consider BESS as an alternative came about due to the following argument. It has been observed that due to rapid addition of solar generation, there are instances of “high frequency” in the grid, especially on days of low power demand. On such occasions, thermal power generation is backed down to accommodate solar generation, to the extent possible. As thermal generation is required during non-solar hours to ensure resource adequacy, these units cannot be simply taken out during high solar generation.
It was therefore felt that addition of solar generation without commensurate energy storage would challenge the flexibility of thermal power plants during the daytime.
Energy storage could thus be considered as a viable alternative. In the case of Rajasthan, a BESS of 6 GW x 4.25 hours at Barmer would cost around Rs.21,675 crore. (This is based on the current rate of $100 per kwh for BESS projects. The 6 GW x 4.25 hour BESS, translating to 25,500,000 kwh, would cost $2,550 million or approximately Rs.21,675 crore.)
The cost of the proposed BESS would be lower than that of an HVDC system (LCC or VSC). The BESS would also provide flexibility support and resource adequacy during non-solar hours. Besides, a BESS would have a considerably low gestation period that of HVDC systems.
Cost-benefit analysis
In view of the discussions, Chairman, Central Electricity Authority (CEA), during the NCT meeting, directed CTUIL to carry out of a lifetime cost-benefit analysis of BESS versus HVDC transmission schemes. This analysis will be deliberated upon at the next NCT meeting.
Featured photograph is for representation only
