From Cyclones to Heatwaves, How Climate Crisis is Tripping India’s Power Sector

Gusting at 260 km per hour--the same as the speed at which an aeroplane takes off--the storm swept away the trees, hutments, food shacks and electricity poles. “Roads got blocked because of fallen trees, so people walked for kilometres to reach the highway where food was distributed for the poor,” he told IndiaSpend.

“Power shutdown lasted for around 10 days and proper supply could be restored only after 18 days. Many transformers in our area had blasted and supply lines snapped,” he said. “We went back to torches and kerosene lamps for lighting. Those owning generators charged Rs 2,000 per hour for powering the household electricity motors that filled up overhead tanks.”

In Visakhapatnam, the cyclone damaged 27 substations, 4,800 transformers and 56,000 electricity poles. Around 20 km away, the Simhadri Super Thermal Power Station of NTPC suffered losses to the tune of Rs 34 crore and lost the opportunity to generate 373 million units because of a shutdown that lasted four days.

It was not the first time that an extreme weather event had triggered a blackout.

Depending on location, power outage minutes in India can increase by 80-220% during days with intense rain (over 40 mm), 20-70% during high wind speed (over 50 metre per second), and by 15-60% during heatwaves (temperature greater than 40°C), a recent study from Delft University of Technology, Netherlands has found. Severe floods in urban areas can increase daily outage minutes with a factor 2.1 to 5.5.

The study combined four years of daily outages data from 370 locations across the country with temperature, wind, rain and flood inundation data. “Our findings highlight how high frequency data can help validate how climate extremes can affect essential services to customers, and how these impacts differ across types of locations,” said the study. “This information is key for those countries that aim to meet universal access to energy in the coming decades, yet at the same time will experience more frequent and intense climate extremes.”

India is already facing deadly heatwaves, cloudbursts, storms and droughts which are bound to get more intense with the climate crisis, as detailed in the 6th Assessment report by the Intergovernmental Panel on Climate Change's (IPCC) Working Group.

Electricity production contributed 48% to India's total carbon dioxide emission in 2020. The power sector also impinges upon natural resources and biodiversity through deforestation to extract coal, submergence and tunneling for hydroelectricity projects and land acquisition for multi-acre solar parks and wind farms. The sector--starting from source to generation to distribution--is increasingly facing the consequences of both extreme weather events and gradual shifts in climate.

For a coal power plant, this can translate into sub-standard fuel, low production or shutdown, but the consequences are disastrous when a nuclear plant or a hydropower project is hit.

IndiaSpend reached out to the Ministry of Power, Ministry of New and Renewable Energy and Ministry of Environment, Forest and Climate Change for comment on the findings, and the strategies to mitigate these impacts. We will update this story when we receive a response.

Design for disaster

Big power plants are usually designed taking into consideration historical rainfall, flood and temperature data. A changing climate and the resulting change in mean and extremes of weather parameters, however, can make these evaluations outdated, resulting in infrastructure operating outside thresholds. This was most evident in Kerala in 2018 when dams, unable to manage the inflow from unusually heavy rainfall, worsened the flood situation.

A study by the Indian Institute of Science found that the ‘rule curve’ for these dams were either not available or not updated since 1983. A rule curve specifies the levels of water to be maintained in a reservoir during different times of the year to serve its purposes which include flood control, water supply for irrigation, industrial and domestic use and probably power generation. These levels are calculated through studies using historic or generated inflow of water.

"The rule curves and standard operating procedures of all big dams need to respond to new realities brought in by the climate crisis. And these documents need to be in the public domain for better monitoring,” Himanshu Thakkar, the coordinator of South Asia Network on Dams, Rivers and People (SANDRP), told IndiaSpend.

Cloud bursts, glacial lake outburst floods, and landslides have damaged hydropower stations at several locations, especially in the Himalayas, over the years.

The 2013 Kedarnath floods caused extensive damage to at least three hydroelectric projects. In 2021, the Rishiganga project was hit by a rock and ice avalanche. In 2023, a glacial lake outburst flood breached the Teesta III dam in Sikkim which had disregarded green norms and other regulations, as reported earlier by IndiaSpend. In 2024, a flash flood damaged 14 projects and killed at least eight workers in Himachal Pradesh.

Many hydropower projects have also added to the crisis. Deforestation, hill cutting, tunneling, mining and muck dumping have made the local geology more vulnerable to extreme weather events.

“Before any hydroelectricity project is set up, its disaster potential assessment should be done which should include the vulnerabilities it would add to the area,” Thakkar opined. “A cumulative river basin assessment is required because damage to any such project would have a cascading effect.”

The country might experience excessive monsoon rainfall in future leading to increased hydropower production, but also to heightened risk of flooding and dam breaks especially in north and central India, found a study from the Indian Institute of Technology, Gandhinagar which analysed the future scenarios for 46 large hydropower dams across the country. “In the absence of reliable early warning and forecast systems, high inflow when reservoirs have already reached their total capacity may require quick release, which can cause flooding in the downstream regions,” the study said.

Last month, the Supreme Court expressed shock that a national committee for dam safety was yet to be formed despite the enactment of the Dam Safety Act in 2021. “We don’t know which projects, if any, have early warning systems for floods because as the court rightly said, the government agencies dealing with these issues are in slumber,” Thakkar said. “At least the insurance companies extending coverage to the hydro projects should flag these issues and ensure compliance besides making the details public.”

While excess rains can cause long-lasting damage, droughts can impact efficiency of hydropower projects. In the last two years, India’s hydropower production fell the steepest in four decades, amid record-high temperatures and erratic rainfall.

Thermal plants and water crisis

In 2019, flooding at the Dipka coal mine disrupted operations for an entire month, leaving power plants in eastern and central India scrambling for fuel. “Coal submerged or drenched in rain loses its firmness, turning into slurry that not only reduces the power plant’s output but also jams the machines,” said an engineer with a coal-based power plant on condition of anonymity, as he was not authorised to talk to the media. “Heat waves can also leave the coal stored in yards smoldering, thus lowering its quality. We often use sprinklers to control the combustion.”

Every year, around 2,500 KJ of heat is lost to smoldering from each kilogram of coal stacked in thermal plants, found a study from the research and development centre of NTPC. “The new supply should be stacked properly and the stored coal should be reclaimed regularly. Regular and frequent watering of the stockpile to keep the coal saturated with moisture may help to reduce the loss to considerable extent,” the study said.

Thermal power plants using coal, gas and nuclear fuel also require cool water to take away excess heat generated in the boiler. On hotter days, however, the water can become too warm, decreasing the capacity of these power plants. The power production loss may exceed 2% per degree Celsius rise in temperature.

Similarly, droughts can hit power production. Around 40% of India’s thermal power plants are in water-scarce areas. Between 2013 and 2016, water shortages caused 14 of the 20 biggest thermal utilities in the country to close down their plants.

For thermal plants, upgrading the cooling systems reduces the water needed. "Some plants are shifting from water-based cooling to air or dry cooling, especially in water-stressed regions, but the uptake remains limited,” said Tashina M. Cheranda, senior associate in the Adaptation and Risk Analysis team of the Climate, Environment and Sustainability sector at think-tank CSTEP, told IndiaSpend. “Most plants still rely on traditional water-intensive systems, making them vulnerable to future climate risks.”

Solar, wind more vulnerable but also more resilient

Solar and wind energy can be more vulnerable to extreme weather events as they are directly dependent on weather. A cyclone or flood impacts these installations similar to other infrastructure, but there are also damages specific to renewable energy.

For instance, extreme heat not only damages solar panels but also reduces power production. Solar panels are built to operate optimally at a certain temperature. Most solar panels can operate at their peak efficiency at a temperature between 15°C and 35°C, said an analysis of wind and solar projects in four states by CSTEP. Higher temperatures can reduce the efficiency of a solar panel by 10% to 25%, it said.

Heatwaves are also known to affect wind energy. Temperatures higher than 40°C can lower the expected wind levels of an area. Average annual wind speeds declined at the rate of 0.88 km per hour per decade over 40 years (1979 to 2019) across India, said an analysis by the Council of Energy, Environment and Water. This was confirmed by another study from Harvard University, which said that warming of the Indian Ocean due to climate change has weakened the Indian monsoon and wind speeds, especially in western India. Western states--Gujarat, Maharashtra and Rajasthan--had over 47% of the total installed wind energy projects till December 31, 2024.

The analysis done by CSTEP also found that around 85% of solar energy projects in Rajasthan and 82% in Maharashtra were exposed to more than three heatwave events in a year. In Tamil Nadu, 11% solar plants were exposed to more than three heatwave events annually. A heat wave is defined differently for varying topographies. In the plains, the maximum temperature has to be 40°C or above; in coastal areas 37°C or more; and in hill regions 30°C or higher, according to the India Meteorological Department.

When it comes to wind energy, all wind turbines in Rajasthan and 25% of turbines in Maharashtra were exposed to more than three heatwave events in a year. All wind and solar assets in Gujarat were exposed to only one heatwave event in a year. Around 42% wind assets were exposed to moderate to severe droughts in Gujarat. Floods were not a very big risk factor in any of the four states.

“Mitigating extreme heat risks requires enhancing the ability of renewable energy developers and plants to anticipate, absorb, and recover from heat waves. There are technological and planning-related strategies that can help achieve this,” said Cheranda. “A technological solution, for example, could be the use of heat-resistant materials. Planning-related strategies, such as early warning systems and risk-informed site selection, can also help minimize exposure to extreme heat.”

Cyclones are another risk factor for renewable energy projects. The analysis found that around 21% of solar projects in Maharashtra and 20% in Tamil Nadu were exposed to very severe tropical cyclone storms (wind speed over 120 km/h). Around 53% wind assets and 36% solar projects were exposed to severe cyclones (wind speed 90-120 km/h) in Gujarat. In Tamil Nadu, 3% wind projects were exposed to very severe cyclones.

The researchers also found that many of the sites had taken some of the precautionary measures like having cooling systems, preventive checks, spare parts, besides speed alarm or cut off system (for wind turbines). “The renewable energy developers are well aware of climate risks because their business depends on the weather,” Cheranda told IndiaSpend. “Past experiences with extreme weather events have underscored the financial stakes involved, pushing them to invest in resilience, not just to comply with policy and regulatory requirements, but as a smart business practice.”

But it’s not just the most evident weather events that imperil renewable energy production. A 2022 study by researchers from Nainital-based Aryabhatta Research Institute of Observational Sciences revealed that aerosols from large forest fires (caused by high temperature or lightning strikes) in forests of Uttarakhand disrupted production of solar energy, resulting in a loss of Rs 78 lakh in 2021.

Aerosols from massive forest fires absorb solar radiation, thus reducing the intensity of the light falling on solar panels. The energy loss due to the presence of aerosols was found to be around 63 kiloWatt-hour per square metre. “The optimum locations for new solar plants have to be far from forests and also where they exist, the solar energy companies can collaborate with the forest department and local communities to prevent and control forest fires,” Umesh Chandra Dumka, a co-author of the study, told IndiaSpend. “This will be imperative considering forest fires are bound to increase with changing climate.”

Days with severe risk of forest fire are likely to shoot up by 60% in dry forests like that of Uttarakhand due to rising temperature, while humid forests like those in north eastern India may see 40% reduction, found another study from IIT Delhi.

One of the adaptation measures to the risks at the generation level can be diversifying the source of energy.

“Besides increasing resilience of each power plant against climate change, having a good mix of all energy sources in the supply line can divide our risks,” said Vrinda Gupta, Associate Director at Vasudha Foundation, a think-tank which brought out a report on resilience of Delhi’s transmission and distribution network under heat wave conditions.

Distribution failures

Transmission and distribution of electricity is particularly vulnerable to extreme weather events because of the vast network and the challenges related to local settings like high density cities or remote villages. This segment of the power sector also has a direct connection to the end user, and hence is more likely to be blamed for a disruption even if it is at the level of generation. A local failure can travel through the electricity system, tripping even the earlier unaffected parts of the system.

“While heat is usually the trigger for rise in demand for power and hence overloading in urban India, monsoon is the time when power failures rise in rural parts,” said Shweta Kulkarni, a fellow with Prayas Energy Group, a Pune-based non-profit which has been furthering public-interest in the energy sector through analysis-based policy and regulatory engagement.

Transmission infrastructure works less efficiently during periods of high temperature because as a line heats up, the amount of electrical current it can safely carry is reduced. The lines also sag because of high temperature and can snap or short circuit, resulting in power failure.

The study from Delft University of Technology, Netherlands, found that in urban areas, outage minutes increased with rising temperature during May-July period as the distribution network got overloaded with high demand of power for cooling devices like air conditioners, coolers and fridges. The trend was less pronounced in rural areas because of comparatively lower access to these devices.

Several strategies can enhance transmission resilience to extreme temperatures. Discoms can use the new, advanced conductors which sag less at high temperature while underground cabling can minimise heat exposure, Cheranda explained. “Heat-resistant or reflective coatings can also lower temperature impacts.”

It was rainfall, however, that emerged as the biggest trigger for power failures, with even days of low rainfall (0-20 mm) leading to 30-40% higher outage minutes. Intense rain (more than 40 mm per day) meant 80-220% rise in outage minutes, with district headquarters being the most affected region.

“There are different adaptation measures that can be taken, depending on the most threatening hazard. Substations, for instance, are quite prone to flooding. We see best practices to elevate substations above ground, or have a small flood wall around them,” said Jasper Verschuur, Assistant Professor in Engineering Systems and Climate Security at Delft University of Technology, who co-authored the study. “However, at the end of the day, it all comes down to good engineering, upgradation and maintenance. Failure to do so leads to increased likelihood of failure.”

Smarter, more resilient grid

Shifting overhead power lines underground can reduce disruption, especially in areas prone to cyclones. Post Hudhud cyclone, the Andhra Pradesh Eastern Power Distribution Company Limited upgraded the overhead electricity distribution network to an underground cable system under a project funded by the World Bank.

In addition, better redundancy in the transmission network helps buffer power failures during extreme weather events. Redundancy means having multiple branches, loops, or feeders to reroute power flow in case of an outage or fault on one pathway. The redundancy of the network is often higher in urban areas versus rural ones.

“Distribution companies (discoms) usually operate through cost evaluation and thus redundancy acquires higher value in urban areas because of the presence of high paying customers and business parks in these areas,” said Kulkarni.

Localised generation with the help of renewables can be another way to reduce load on overburdened networks and prevent failures. This has been especially successful in case of power supply for farm irrigation in states where agricultural feeders have been separated from the residential feeder system.

Prayas Energy Group has worked with the state of Maharashtra to install solar energy plants at the local feeder level. A solar-powered agriculture feeder is a 1-10 MW community-scale solar plant, which is interconnected to the 33 or 11 kV sub-station. A 1-MW solar plant can support around 350 five-horsepower pumps.

When solar generation is low, for instance due to cloud cover, the balance electricity can be drawn from the main grid while at other times when excess solar power is generated, it can flow back to the grid.

“Solar feeder improves reliability of power supply as it can be managed locally, improving fault finding and reducing voltage distortion and transmission loss. It has also provided additional benefits because generally, discoms supply power for irrigation late at night or early morning hours,” said Kulkarni. “This means safety concerns for farmers and wastage of water because many farmers would let the pumpsets run for long instead of monitoring irrigation at odd hours. The day time supply with solar is more convenient and also reduces cost of distribution for the discom. And since it is not a farm-based solar plant, farmers don’t need to worry about their upkeep.”

Rooftop solar installation is another option for decentralised power generation but it has not performed as expected. The target of 40 GW for the year 2022 was shifted to 2026 due to poor uptake, low awareness, delay in approvals and lack of uniform regulations, as reported by IndiaSpend earlier. By December 2024, India added 15.67 GW capacity under rooftop solar with Gujarat, Maharashtra and Rajasthan leading the pack.

There have also been many improvements in the distribution and transmission network of India over the years.

“The transmission network in urban India at least has become more stable. The power blackout of 2012 when northern and eastern grids collapsed due to overload is behind us. There are more high voltage direct current lines which are more stable and efficient than alternate current lines,” said Gupta. “Uptake of smart meters has increased and work is also going on smart grids which can monitor power flows, reduce losses, and increase reliability of the supply of electricity. All of this will be helpful when faced with an extreme weather event.”