For a mother preparing lunch while her children wait impatiently at the dining table, a small shopkeeper struggling to keep his business running, or a student sitting before a computer completing an important assignment, a sudden power failure is more than a temporary inconvenience, particularly in a country where repeated electricity interruptions have become an uncomfortable reminder of how easily everyday life can be disrupted by failures in a system on which almost everyone depends.
When electricity disappeared across Sri Lanka shortly before noon on 17 October, the familiar silence of household appliances, interruptions to business activities, and uncertainty surrounding restoration brought back memories of previous nationwide blackouts, leaving consumers wondering why, despite years of investigations, recommendations, and investments in electricity generation, the country continues to experience disturbances capable of bringing the entire national grid to a standstill.
The latest blackout, which occurred at approximately 11.43 a.m. following the sudden disconnection of a generating unit, developed into a nationwide system failure, forcing engineers to undertake a gradual restoration process. The subsequent shutdown of the Norochcholai coal power plant removed approximately 810 MW of generating capacity and created additional electricity supply difficulties in the days that followed.
Beyond the immediate disruption, however, the incident has reopened questions about Sri Lanka’s preparedness to accommodate rapidly expanding renewable energy generation, the implementation of corrective measures recommended following earlier blackouts, and the responsibilities of institutions operating under the recently restructured electricity sector.
A decade of blackouts and repeated investigations
Sri Lanka’s experience with nationwide electricity failures stretches well beyond the latest incident, with successive investigations identifying weaknesses involving transmission infrastructure, maintenance procedures, protection systems, and operational arrangements, although the circumstances surrounding individual blackouts have differed considerably.
In March 2016, a major power system failure left much of the country without electricity for more than eight hours, while another islandwide blackout on 17 August 2020 resulted in several hours of disruption following a maintenance-related incident at the Kerawalapitiya Grid Substation.
The Government-appointed committee investigating the 2020 blackout identified deficiencies in operational risk management and maintenance procedures, recommending improvements to supervision, technical safeguards, and institutional practices intended to prevent similar failures.
However, another major blackout occurred on 3 December 2021 following a disturbance involving the Kotmale–Biyagama transmission system, with the subsequent investigation examining the technical failure and difficulties encountered during electricity restoration.
According to the Public Utility Commission of Sri Lanka’s (PUCSL) public hearing records, approximately 9.65 GWh of electricity demand remained unserved, while the estimated economic cost of the 2021 failure was approximately Rs. 1.505 billion, demonstrating the financial consequences of disruptions that extend beyond the immediate inconvenience experienced by electricity consumers.
Another nationwide blackout followed on 9 December 2023, with initial investigations pointing towards a lightning-related disturbance affecting the transmission network, while the 9 February 2025 failure brought renewed attention to the challenges of maintaining system stability during periods of high solar generation and relatively low conventional generating capacity.
The February 2025 blackout resulted in approximately 5.5 GWh of unserved electricity demand, according to PUCSL figures, while rotational power cuts introduced afterwards accounted for another 4.6 GWh, bringing the combined amount of electricity demand that could not be supplied to approximately 10.1 million units.
These figures illustrate the broader economic implications of repeated nationwide failures, particularly for small businesses, industries, and services that depend on reliable electricity, while also raising questions about the implementation of recommendations arising from previous investigations.
Against this historical background, the 17 October blackout has once again brought attention to whether the country’s electricity infrastructure has developed sufficient resilience to withstand unexpected disturbances.
Could batteries have prevented the blackout?
Speaking to The Sunday Morning, National System Operator (NSO) Chairman Dr. Pradeep Perera explained that the 17 October failure had followed the sudden loss of approximately 180 MW of generation, which was exacerbated by the disconnection of solar energy in response to the drop in frequency, creating an immediate imbalance between electricity supply and demand that the remaining generating units could not correct quickly enough.
According to him, the Victoria Hydropower Station responded with approximately 50 MW, but this was insufficient to compensate for the sudden loss, while other generating units required more time to increase their output. This delay has caused the system frequency to drop below the safe operating levels and total system collapse within 30 seconds of the initial disconnection of 180 MW capacity.
He maintained that the availability of approximately 200–300 MW of battery energy storage could have made a significant difference, as batteries can respond almost instantaneously to disturbances and provide frequency support until other generating units respond.
However, the Chairman acknowledged that the development of Sri Lanka’s electricity system had not been sufficiently coordinated prior to 2025, particularly following the rapid expansion of solar generation during and after the economic crisis, when private investment in renewable energy increased considerably while supporting grid support infrastructure developed at a slower pace.
He explained that solar development had brought substantial benefits by reducing dependence on expensive oil-based generation, but that the expansion was not accompanied by equivalent investments in battery storage, synchronous condensers, and other technologies necessary to maintain system stability.
According to Dr. Perera, several corrective measures were identified following the February 2025 blackout, including the procurement of battery storage systems, improvements to solar power plant controls, adjusting the low frequency and low voltage ride through the capability of solar inverters and the installation of synchronous condensers, which help maintain system frequency when sudden disturbances occur.
Nevertheless, many of these initiatives remained under implementation when the latest blackout occurred, with the Chairman attributing delays to the requirement to adhere to Government procurement procedures and the time taken for implementation after contract award.
He explained that procurement processes alone could take six to eight months, while infrastructure development required additional time, particularly when projects involved substantial investments, adjusting inverter settings in a large number of locations, and relatively new technologies.
The NSO is currently implementing several battery storage programmes, including an initial 160 MW project which was tendered by the Ceylon Electricity Board (CEB), a further 250 MW battery energy storage system project tendered by the NSO recently, and an additional 150 MW of battery installations associated with existing solar plants, together with a separate 100 MW project in Kolonnawa.
Dr. Perera expects approximately 660 MW of battery storage to become available by the second half of 2027, which he believes would significantly strengthen the electricity system and reduce its vulnerability to sudden disturbances.
However, he acknowledged system failures remained a possibility even in developed countries and that the objective should be to minimise risks through appropriate investments and operational improvements.
Restructuring and institutional accountability
Apart from the technical challenges, Dr. Perera acknowledged that restructuring the electricity sector had allocated responsibilities for power system operation among several successor entities and private sector investors in renewable energy and energy storage, and that the NSO’s role was limited to coordinating overall power system operations to minimise the cost of energy without compromising system security.
While the NSO will undertake an initial assessment of how the recent incident was initiated and the response to the initial disconnection of 180 MW of generation capacity by other power plants connected to the system, including privately owned solar plants, as required under the Grid Code, a more thorough and comprehensive investigation has to be undertaken by a higher authority. It should also result in binding recommendations for corrective actions and measures to minimise the risk of similar incidents in the future.
He said that such an investigation would need to examine the responses of individual power plants, protection systems, and other operational decisions to establish the complete circumstances of the failure, while acknowledging that the NSO did not possess all the information necessary to independently investigate every institution involved.
He nevertheless cautioned against assuming that the blackout had resulted from deliberate wrongdoing, explaining that disturbances could occur in electricity systems and that the more important issue was whether sufficient safeguards existed to prevent individual failures from developing into nationwide collapses.
His observations bring renewed attention to the arrangements for investigating major incidents following the electricity sector reforms, particularly when technical failures may involve several institutions operating under separate management structures and a large number of privately owned distributed generation sources which cumulatively form a substantial share of operating capacity.
Solar industry calls for a different approach
While the NSO has emphasised the importance of centrally controlled battery storage and coordinated electricity planning, solar industry representative Kushan Jayasuriya believes the country should have given greater attention to developing household and community-based energy storage alongside the expansion of rooftop solar installations.
According to Jayasuriya, the increasing contribution of solar electricity should not itself be considered a problem, particularly when rooftop installations have helped reduce daytime electricity generation costs and dependence on expensive conventional power plants.
“The blackout is a result of not having sufficient batteries,” Jayasuriya maintained, arguing that the authorities should have anticipated the challenges associated with increasing solar penetration and introduced policies encouraging consumers to install storage facilities before restricting rooftop solar development.
He explained that electricity generated by rooftop installations during the daytime could be stored for use during evening peak demand periods, helping reduce pressure on the national grid while enabling households to make greater use of the electricity they produced.
“We should have slowly encouraged households to use batteries, rather than just curtailing the entire rooftop programme,” he said.
Jayasuriya suggested that the Government could introduce incentives or requirements encouraging new solar installations to include a reasonable level of battery backup, allowing storage capacity to develop gradually across households and businesses instead of depending primarily on large-scale projects.
He also questioned the policy direction affecting rooftop solar development, maintaining that the industry had played an important role in reducing generation costs and should be supported through measures addressing grid limitations rather than restrictions that could discourage further investment.
“The generation cost during the daytime is less because of solar. It is because so much solar has been added that the generation cost during daytime has come down,” he explained.
According to him, growing consumer interest in household batteries, partly driven by electricity tariffs and uncertainty surrounding future energy policies, demonstrated that there was already demand for storage solutions, even in the absence of a comprehensive community-based policy.
He maintained that appropriate regulatory arrangements and financial incentives could encourage more households to invest in battery storage, allowing consumers to participate directly in strengthening the electricity system while reducing their dependence on grid electricity during peak hours.
“The fastest way is to implement it through the community. I don’t know why we are looking at other avenues,” Jayasuriya said.
He further argued that the Government should consider alternative financial mechanisms for encouraging household storage, even if existing feed-in tariff arrangements were revised, rather than allowing uncertainty over rooftop solar policies to discourage investment in renewable energy.
His observations highlight the industry’s concerns over balancing renewable energy expansion with technical requirements, particularly when a growing number of households have already invested considerable sums in rooftop installations.
Regulator awaits technical findings
Meanwhile, PUCSL Director General Damitha Kumarasinghe said that the commission was awaiting the preliminary technical investigation report from the NSO before commenting on the circumstances surrounding the 17 October blackout.
He said that the full technical report was expected within one month and explained that the regulator was not in a position to reach conclusions regarding the incident until the relevant findings had been received and examined.
The commission’s position leaves several questions to be addressed through the investigation, including the precise circumstances leading to the initial disturbance, the response of the electricity system’s protection mechanisms, and whether additional safeguards could have reduced the severity of the failure.
Previous investigations have demonstrated that identifying the technical incident triggering a blackout does not necessarily provide a complete explanation of why the entire electricity system collapses, particularly when the consequences depend on several interconnected factors, including operating conditions, generating capacity, and protection arrangements.
The findings of the latest investigation will therefore be important not only in establishing what happened on 17 October but also in determining whether further technical or institutional measures are required to reduce the likelihood of similar incidents.
As Sri Lanka moves towards its target of generating 70% of electricity from renewable sources by 2030, the challenge confronting policymakers is no longer limited to expanding generation capacity, but increasingly concerns the ability of the national grid to accommodate that electricity while maintaining reliability and controlling costs.