The task of running one of the world’s largest nationwide power grids is a unique challenge. How is it done?
As India makes a concerted push to go green, the share of infirm sources such as solar and wind power will have to rise, which will add to the complexity of grid management.
NEW DELHI :
Not many who pass by a nondescript building on the way to the Sitaram Bhartia Institute of Science and Research in south Delhi would be aware of its importance in their lives. Nestled into south Delhi’s leafy Qutab Institutional area, this building houses the National Load Despatch Centre (NLDC)—the nerve centre of India’s power grid system.
It is the NLDC that sits at the top of an extensive network designed to ensure that India gets the electricity that it needs. Often unimaginatively compared to the air traffic control, it’s the NLDC’s highly trained team of operators, working in three stressful shifts of eight hours each, who keep an eagle eye on India’s national power grid— capable of transferring 105 gigawatts (GW) of electricity from one corner of the country to another. To put this into perspective, this quantum of electricity is enough to take care of the entire power demand of the UK. While orchestrating this daily dance of moving electricity across the country is a challenge even under normal circumstances, the covid-19 pandemic has imposed some unique difficulties. Power demand fluctuated over the course of 2020, as many industries shut and homes consumed power for longer durations.
“We run the single largest synchronous grid in the world. There are challenges but we have managed (during the pandemic)," said K.V.S. Bawa, chairman and managing director, Power System Operation Corp. Ltd (Posoco). State-run Posoco oversees the country’s critical electricity load management functions through the NLDC and a set of regional load dispatch centres (RLDCs) and state load despatch centres (SLDCs). India has 33 SLDCs, five RLDCs—for the five regional grids that form the national grid—and one NLDC.
“What will happen if (the) electricity stops?" wonders Sushil Kumar Soonee, an advisor with Posoco and the man credited with building a robust power system that dances in tandem to fulfil the country’s electricity needs. A grid collapse is the worst-case scenario for any transmission utility; if this happens, states that draw power from that particular network will go without power. “It is difficult to explain the immensely complex set of operations that ensure a continuous flow of electricity. Like all good things in life, one’s presence is only felt by one’s absence. While the electricity demand came down during the pandemic, its value was felt manifold," Soonee, who earlier headed Posoco, added.
One of the key pressure points in managing the load dispatch centre is the fact that multiple fuel sources feed India’s growing demand for electricity. India has an installed power generation capacity of 383.4GW. Of this, coal-fuelled plants account for more than half of the total share (about 202GW), with gas, nuclear and hydro accounting for 25GW, 7GW and 46GW, respectively. As India makes a concerted push to go green, the share of infirm sources such as solar and wind power will have to rise, which will add to the complexity of grid management. Solar and wind currently constitute 96GW in the electricity mix. “It is a big orchestra and (the) entire orchestra has to continuously create a symphony, wherein, the instruments and the musicians keep on changing," said Soonee.
Given the number and types of power generation plants, electricity transmission links and distribution loads spread across the country, there should be a perfect symphony so that the holy grail of India’s power system management is met—a grid frequency in the range of 49.9–50.05 hertz (Hz). This involves close coordination between the grid operators and the power generators—across coal, gas, hydro, nuclear and green energy sources—managed by the Centre, states and the private sector, with every part of the closely linked chain involved in transmission and distribution sector doing their job. A small error, if not rectified in time, can shut down the entire grid.
“The grid has to match the consumption with generation in real-time which is not easy, particularly with an increasing share of renewable energy resources that are intermittent," said Reji Kumar Pillai, president, India Smart Grid Forum, a public-private partnership formed by the power ministry. “When a customer switches on an appliance, that additional power should start flowing from the grid and the grid operators have to get that extra power from the cheapest generation sources."
With the Indian grid starting to get connected to the neighbourhood, the problem only gets exacerbated. The Union government plans to set up a regional grid that will be leveraged to create a common electricity market for the neighbouring countries. While India already has power transmission links with Bhutan, Nepal and Bangladesh, the plan is to establish a connection with Myanmar and Sri Lanka.
“Over the years, the power system has been so oversimplified for the users that they often forget the mammoth effort that goes on 24x7 to ensure that electrons start flowing the moment a customer switches on a light or a machine," Pillai, who is also chairman of the Global Smart Grid Federation, said.
Training fighter pilots
It takes years of training for an operator to take command in the control room. With an exceptional sense of situational awareness, they are gradually eased into the process by being acclimatized. Apart from training on simulators, this involves regular examination and certification. An operator is really tested only when things go awry. “That’s the time when situational awareness is important. It takes time to train an operator. They are like jet fighter pilots. In the control room, we are always questioning—what is happening? Why is it happening and what is likely to happen? It is like having plan B, C, D, E and F in place… all at the same time," Soonee said.
Everything has to be calibrated—be it the prevalent temperature, weather, season, the availability of a particular power plant or a transmission link and even if it is the finals of the Euro cup on a certain day. With football fans switching on their television sets at 12.30 am on match day, the power system had to calibrate for the sudden demand surge.
This requires an astute understanding of all the moving parts. In such a scenario, various fuel sources provide different sets of solutions. India’s hydropower stations play a key role in balancing the grid. These hydropower plants can be swiftly turned on and off, unlike thermal power plants which usually take around four hours to be brought online if the boilers are already lit and a day in the event of a cold start. In comparison, gas-fuelled projects take around 30 minutes to come online. While the hydro plants take the least time to be switched on or off, they are also prone to unforeseen risks.
The operators need to calibrate for all types of exigencies, such as an abrupt rise in the silt levels—as was seen in the waters of the Rishiganga river following a glacier burst and flash flood in Uttarakhand in February this year. This prompted some hydropower plants that were located downstream to curtail operations in order to protect their turbine blades from the high silt content, thereby resulting in that generation capacity being taken offline.
“Our (grid) system operators in India have been among the finest in the world," said Shubhranshu Patnaik, partner at Deloitte. “Grid reliability has been achieved despite lower levels of automation than the western world, lack of meaningful ancillary services and a significant weaknesses at the intra-state level," he added.
While their ability to handle sudden exigencies is constantly tested, sometimes, the operators do get a curveball—even by their standards. The latest case in point was what unfolded on the evening of 5 April 2020, in the early days of what would end up being a prolonged nationwide lockdown.
At 9 pm on 5 April, heeding Prime Minister Narendra Modi’s call, India switched off lights for 9 minutes. The load sharply dropped and kept on falling as people switched off more than just lights. The estimated electricity load reduction went off the charts and was at 32GW—enough to meet the entire power demand of Pakistan. The unprecedented ramp down and the subsequent build-up of electricity load had to be done successfully, within a small window of nine minutes—something that hasn’t been tried anywhere in the world on such a scale.
Any sudden change in demand pattern could impact the grid frequency, with the global standard requiring the frequency to be kept close to 50Hz. The April performance also added heft to the ambitious global electricity grid plan, which aims to leverage solar power generated in one geography to feed the electricity demands of other nations through the ambitious “One Sun, One World, One Grid" (OSOWOG).
What makes an already arduous task more difficult are the cyberattacks on the Indian power grid. The grid is under constant attack, with at least 30 events reported daily, as reported by Mint earlier. A majority of the attacks originate from China, Singapore, Russia and the Commonwealth of Independent States (CIS) countries. The attacks reached a crescendo earlier this year, when Red Echo, a hacker group affiliated with the Chinese government, repeatedly targeted India’s load dispatch centres. The massive campaign could have caused widespread blackouts.
“This is a real and present danger. Imagine the consequences if only one such attack is successful. If power supplies get switched off, the country comes to a halt," said a top government official requesting anonymity. After the attack, a massive training exercise has been initiated, with particular emphasis on the types of cyberattacks that one has to watch out for. Access denial training is also underway to make the grid harder to penetrate.
When the music stops
Even the best-laid plans can often go awry. This came to bear when India witnessed massive power transmission failures in mid-2012, which left around 700 million people without electricity.
On 31 July, the northern grid collapsed, and on 1 August, the blackout widened bringing down the northern and eastern networks as well. According to experts, a variation in electricity demand led to a dip in the voltage. This dip in voltage, in turn, tripped a critical transmission link and led to a domino effect, tripping other links. This affected electricity supplies to states such as Delhi, Uttar Pradesh, Punjab, Haryana, Rajasthan, Uttarakhand, Himachal Pradesh, Chandigarh and Jammu and Kashmir.
Unlike the power systems in Europe, China and US that have stabilized, India’s power system is still on a high growth trajectory. By 2030, power requirement would stand at 817GW with more than half of the demand being met by clean energy, according to Central Electricity Authority (CEA), the country’s apex power sector planning body. “We are in the adolescent stage, which comes with its own set of problems. We have to go from ‘fan to fridge’… and the grid has to grow more," Soonee added.
This comes at a time when the Cabinet Committee on Economic Affairs recently approved the marquee ₹3.03 trillion power distribution company (discom) reform scheme aimed at improving the reliability and quality of power supply. As part of the plan, the Union government aims to have supervisory control and data acquisition (Scada) across urban areas and a distribution management system (DMS) in at least 100 urban centres.
Moreover, the system will also have to take into account India’s energy transformation plan that involves a raft of green measures, including clean electricity, green mobility, battery storage and green hydrogen to help reduce pollution and facilitate commitments made at the 21st conference of the parties (COP-21), the United Nations (UN) climate change conference, held in France in 2015.
Several states and power distribution companies are also working on setting up defence mechanisms, such as “islanding". Such a system helps isolate the fallout of a grid disturbance on the national power grid, restricting it to a particular region. This mechanism also allows a particular region or essential service provider to isolate itself in the event of a grid failure.
However, these measures are still some time away from becoming a reality in most parts of the country. And until these proposals turn into reality, it is the grid operators who will have to ensure a safe flight path for India’s power grid, even as the country’s peak electricity demand continues to scale to an all-time high (it recently breached the 200 GW mark). The task will require constant training, up-to-date technology and a lot of grit and determination.
“One wrong move, and a symphony becomes a cacophony," cautioned Soonee.
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