Transmission line addition on ISTS network surges in 4MFY27

Transmission line addition on the interstate transmission system (ISTS) more than quadrupled year-on-year during the first four months (4M: April to July) of FY27.

According to latest statistics released by Central Electricity Authority (CEA), a total of 2,466 ckm of transmission lines were added on the ISTS side in 4MFY27 – more than four times the comparable 607 ckm in the same period of FY26.

Further, ISTS line addition in FY27 exceeded that on the intrastate transmission system (InSTS) – a phenomenon unprecedented in recent history.

Between the period FY21 to FY26, the quantum of ISTS transmission line addition has been around 42 per cent of the total line addition. In FY20, however, this ratio was nearly 58 per cent. (See table).

 

 

Power Grid Corporation of India Ltd (PGCIL) dominated ISTS line addition with a contribution of 1,973 ckm or 80 per cent of the total. PGCIL’s achievement included 1,276 ckm on the 765kV side and 697 ckm of 400kV lines.

Going by current estimates, PGCIL is expected to commission 4,799 ckm of transmission lines during the entire FY27, marginally higher than the 4,715 ckm added in FY26.

 

Overall performance

During 4MFY27, total transmission line addition, at 4,081 ckm, fell short of the planned addition of 6,747 ckm. The biggest shortfall was seen in the private sector ownership class that could commission only 321 ckm of lines as against 1,589 ckm planned.

In terms of voltage, the highest addition in 4MFY27, at 1,757 ckm, was seen in the 400kV class. In the 765kV voltage bracket, a total of 1,413 ckm was added, just about half of the 2,819 ckm targeted. Here, the private sector faltered with a measly addition of 137 ckm in the face of a 1,013-ckm target.

State transmission utilities commissioned 1,787 ckm, meeting nearly 70 per cent of the planned addition of 2,558 ckm.

 

Interregional transfer capacity

As of July 31, 2026, India’s total interregional (IR) transfer capacity was 1,20,340 MW, a level unchanged since June 30, 2025. The last addition to IR transfer capacity had taken place in June 2025 when 1,600 MW was added on the ER-WR corridor. This, in turn, was the result of PGCIL commissioning an ISTS-TBCB project housed under “Powergrid ERWR Power Transmission Ltd” involving the 400kV double-circuit Jeypore (Odisha, ER) to Jagdalpur (Chhattisgarh, WR) line of about 136 ckm.

Note: This story takes into account transmission lines of 220kV or above, only.

 

Featured photograph (source: Bajel Projects Ltd) is for representation only