Power-starved Uttar Pradesh is faced with a paradox of sorts. Despite the commissioning of four high-capacity 765kV inter-regional Power Grid Corporation (PGCIL) transmission lines between the western and northern regions, the northern state is not being allowed to draw power from generating stations in Chhattisgarh, with whom it has long-term power purchase agreements (PPAs) totalling about 2,000 megawatts (MW).
There was a glimmer of hope when the long-pending Gwalior-Jaipur-Bhiwani 765kV lines, each capable of carrying 2500 MW-3000 MW, were commissioned in August 2015, which reinforced the existing links between the country’s northern and western regions. Following this, PGCIL — the state-owned transmission major — was expected to announce a substantial increase in permitted power flow from the western region to the north. This reinforcement notwithstanding, an increase of a mere 1,750 MW has been allowed in reality.
This is presumably because in the wake of the grid failure of 2012, both PGCIL and grid manager POSOCO have turned so risk averse that they seem to prefer under-loaded lines even if it means load-shedding in Uttar Pradesh or bottling up of power in Chhattisgarh and Odisha. While Uttar Pradesh is badly impacted, private generators or IPPs in Chhattisgarh and Odisha are much worse affected. With the commissioning of a large number of pit-head power stations in Odisha and Chhattisgarh over the last five years, the northern states had contracted to buy cheap power from these stations. In grid parlance, all of these power stations, including those in Odisha, fall under western region of the grid that is bracketed as the ‘W3’ zone. As a result of the skewed transmission line execution, the western region has emerged surplus in power and the demand is limited to either the north or the south.
The transmission problem has been accentuated by the trend among northern states such as Haryana and Punjab to back down generation from their own costly power plants in order to reduce their power purchase cost. The distribution companies or discoms in Delhi too want to exit from the PPAs that they have with costly power plants of NTPC Ltd that include Badarpur, Jhajjar and Auriya.
As a result of this clamour for buying cheaper power, severe transmission constraints are evident on the west-north transmission corridors. On the other hand, the newly commissioned IPP power plants in Chhattisgarh and Odisha have to frequently back down and have been faced with question marks on their financial viability. A number of them are reportedly running at a loss and finding it difficult to meet their debt obligations. For instance, according to the Central Electricity Authority’s generation report, in Chhattisgarh, three 600MW units of Tamnar TPS (thermal power station), one 685MW unit of Raikheda TPS, one 300MW unit of Pathadi TPS and one 250MW unit of OP Jindal TPS have been under ‘reserve shutdown’ for quite a few months. Reserve shutdown, in technical parlance, means a lack of demand, including inability to tie up with buyers due to non-availability of transmission corridor. Similarly, in Odisha, the 600MW units of Sterlite TPS and Derang TPS have had to frequently back down due to congestion in transmission corridors towards the north as well towards the south.
A PGCIL official indicated that the utility was in the process of “observing” the performance of the new 765kV Gwalior- Jaipur and Jaipur- Bhiwani lines and that line loading is being done progressively. That is little respite for states such as UP, who allege that despite there being four parallel 765 kV inter-regional lines between the western and northern regions (Gwalior-Agra and Gwalior-Jaipur, two each) and each line being capable of carrying 3,000 MW power, just an incremental 1,750 MW is being allowed to flow on them.
The power flow on the Gwalior-Agra lines, which should be normally allowed at least up to 2,500 MW, is currently restricted to 1,400 MW. Earlier, when the grid tripped in July 2012, the flow in this line had been restricted to 1,000MW and then allowed up to 1,250MW from 31 Dec 2012.
“Such is the level of under-utilisation of transmission assets that 765kV system is often operated at a capability level of 400kV system,” a government official involved in the exercise said. The tariff format of the Central Electricity Regulatory Commission, though, is such that PGCIL revenues remain unaffected despite under utilisation of its assets. At the time of grid failure in 2012, only one line was available from Gwalior to Agra, and it had tripped due to mal-operation of protection scheme, resulting in cascade tripping. It is learnt from experts in the field that with four parallel 765kV high capacity lines in place, in addition to two HVDC inter-regional links, the WR-NR bond has become quite strong and it should be technically feasible to increase the power transfer capacity from west to north to about 10,000MW so that assets are optimally utilised. The restriction imposed in 2012 in the aftermath of a grid failure should now be put to a stop.