Ladakh region of Jammu and Kashmir, comprising of Leh and Kargil districts, is one of the highest inhabitation in the world. Due to its difficult terrain, most of the Ladakh region is not electrically connected with the rest of the Power Grid. Because of this, power demand of the area is met by some local small Hydel and diesel generators. During winters, generation from hydro projects reduces considerably whereas power demand increases. While in summers, hydel generation is at maximum level whereas demand is generally low. Therefore, to have uninterrupted power supply in and around Ladakh area, connectivity with Northern Region Grid was envisaged. Moreover, due to presence of defence establishments in the area and its strategic importance, it was felt essential to get connected with rest of the grid.
Accordingly, a project was envisaged for implementing transmission system from Alusteng (Srinagar) to Leh via Drass, Kargil, Khalsti at 220 kV level in order to connect Kargil and Leh regions with the Northern Grid by POWERGRID on consultancy basis. Upon commissioning of the transmission system, the same was to be transferred to PDD, J&K for carrying out Operation and Maintenance and other related activities. The downstream network at 66 kV level is being implemented under Deen Dayal Upadhyaya Gram Jyoti Yojana (erstwhile RGGVY) by PDD, J&K.
The project was commissioned on 31.01.2019 and dedicated to the nation by the Hon’ble Prime Minister on 03.02.2019.

Subsequent to reorganisation of the erstwhile State of Jammu & Kashmir(J&K) into UTs of J&K and Ladakh, Ministry of Power vide re-designated 220 kV Srinagar-Leh Transmission System as ISTS and has transferred to POWERGRID with effect from 31.10.2019, i.e. effective date of formation of the two UTs of J&K and Ladakh.