Intermittency of supply in renewable energy has created a need to strengthen the power transmission systems. The government-promoted Power Grid Corporation of India Limited (PGCIL), which also enjoys the status of Central Transmission Utility and is the largest power transmission network operator in the country, has rolled up its sleeves to tackle the upcoming energy transition. At the same time, private players who are new entrants to the business of transmission and renewables are also gearing up.
While PGCIL claims to be in sync with the advances in technology and changing energy scenario, Adani Transmission Power, the largest private sector player in the segment, is aiding expansion of the network. The company owns close to 10,000 circuit kilometre of network. Besides, Essel Infra, Kalptaru Power, Sterlite Grid etc. are planning investment in the sector.
For a nation like India, whose base energy load has been coal and the system is designed around it, the challenge of evacuation of clean energy and last-mile connectivity is crucial.
Under the Paris Climate Change pact, India has envisaged 40 per cent of its total energy demand to come from renewable sources by 2022. In the last seven years, the installed solar capacity has grown from a minuscule 2 Mw to 12,000 Mw by March 2017. Wind power capacity has touched 25,000 Mw. Transmission line coverage of 7 lakh circuit kilometre caters to 3 lakh Mw cumulative generating capacity from all sources.
The Paris agreement did not mention the role of transmission but sector experts have been voicing concerns on grid support. Also, India’s technology transition for this segment is comparable to the best in the world. For instance, the National Transmission Asset Management Centre (NTAMC) in Manesar, Haryana, monitors and controls all substations of PGCIL.
“What you see at NTMAC is a repository of data being updated real-time. We have details of every transmission network, substations and data on power flow and outages. We are timing here the faults, power demand patterns and the region’s behaviour vis-à-vis power supply,” said S K Srivastava, additional general manager, PGCIL.
In all 192 locations with nine control centres across India, of which seven are regional and two at the national level, are connected. The plan is to connect 219 locations besides future capacity. In two years, Renewable Management Centres (REMCs) to manage Green Energy Corridors (GEC) would also feed into NTAMC.
PGCIL is readying other plans, too. “It’s not that the record capacity addition that would be the game changer, it would be transmission. A country’s grid should stand the test of time and technology. Among the major driving forces for transmission would be a continued thrust on seamless and flexible grid interconnection,” said I S Jha, chairman and managing director, PGCIL.
For the next three years, PGCIL has a plan to invest Rs 91,000 crore including the ambitious GEC that has an initial estimated cost of Rs 40,000 crore. GEC, an alternative transmission network to evacuate and blend renewables in the national grid, was designed in 2011. The earlier envisaged investment in the project is likely to increase manifold after the target for renewable energy has been increased five times by the current BJP government.
GEC is under construction in the renewables-rich states of Rajasthan, Gujarat and Tamil Nadu. The projects have been expedited in locations where solar parks with more than 500 Mw capacity are coming up, such as in Rajasthan, Andhra Pradesh and Madhya Pradesh. MP is luring generators by offering seamless transmission in and around the state and waiving off charges for the same. As the wind projects have been bid, PGCIL would also expedite work in west and south India to evacuate wind power to non-windy states in the north.
R N Nayak, former chairman and managing director, PGCIL, who piloted the GEC project, said both demand and supply need to be flexible to secure the grid. “The Indian power system needs to be equipped with a quick start and stop as well as low technical minimum operation of generating plants,” said Nayak.
To enable the same, PGCIL has embarked on Real Time Dynamic State Measurement. In order to have better supervision and control of Indian electricity grid, nationwide installation of phasor measurement units (PMU) has been initiated through Unified Real Time Dynamic State Measurement (URTDSM) programme.
The plan is to instal PMUs at close to 1,300 locations in the first phase, of which 1,000 have been installed. In the second phase, 500 PMUs will be installed along with a network of Optical Ground Wire for facilitating communication services along the transmission network. This will improve grid reliability, reduce probability of blackouts and minimise the impact of grid curtailment. It will also pave way for remote communication and management of power supply till the consumer’s end.