Sri Lanka is once again preparing for potential solar grid instability as the nation’s energy demand dips during early 2026. Officials warn that the expanding solar sector is pushing the grid to its limits despite ongoing investments and planned stability measures.
Sri Lanka faces rising solar grid instability risks as demand dips and new fixes emerge
Sri Lanka’s power sector is bracing for another period of solar grid instability early next year, echoing the disruptions experienced in previous seasons when electricity demand fell sharply. Energy Minister Kumara Jayakody warned in parliament that the combination of low consumption and rapidly increasing solar generation continues to challenge the national grid’s capacity to maintain balance. As the country accelerates its shift toward renewable energy, these fluctuations have become more frequent, revealing gaps in the existing infrastructure’s ability to manage variable supply.
The issue gained national attention during the widely discussed “Sunny Sunday blackout,” when an unexpected shutdown occurred after a wild animal intrusion led to sudden changes in grid behavior. Because rooftop solar lacks the inertia provided by traditional rotating generators, the grid was unable to recover quickly, exposing a key structural weakness. Minister Jayakody explained that similar circumstances are likely to arise again unless stabilizing technologies are implemented on a wider scale. He noted that while the United States often experiences grid instability due to squirrels disrupting power lines, Sri Lanka’s incident involved a monkey—an example of how external triggers can combine with structural vulnerabilities to amplify risks.
By October 2025, Sri Lanka had connected 800 megawatts of solar power, most of it rooftop-based, marking a significant increase from the 533 megawatts recorded the previous year. Officials expect that by the end of 2025, total solar capacity will surpass 900 megawatts, possibly reaching the 1,000-megawatt mark. This rapid expansion, while aligned with national renewable energy goals, is also contributing to the grid’s growing volatility, especially during low-demand periods such as holidays. Last year, the Ceylon Electricity Board (CEB) limited solar power purchases from large suppliers to prevent system imbalance, leading to pushback from industry groups. These businesses argued for take-or-pay contracts similar to those used in African markets to help developers financially sustain capital-intensive projects.
The proposed solution gaining traction worldwide—and now in Sri Lanka—is the integration of large-scale battery energy storage systems. These systems store excess solar energy produced during the day and release it at night, smoothing out fluctuations in supply. The government is currently evaluating private sector proposals for a 160MW/640MWh storage project under a build-operate-transfer model. These battery facilities, planned across 16 grid locations, are expected to enhance system resilience by providing rapid response support, even during localized faults that can trigger sudden voltage changes. Unlike rooftop solar installations, batteries can react instantaneously to disturbances, offering grid operators a vital tool for preventing widespread instability.
Initial tender results for battery storage under build-own-operate terms indicate an approximate cost of 17 rupees per unit of stored and discharged electricity, according to Minister Jayakody. While this figure reflects the investment required to stabilize the emerging renewable-heavy grid, the government is also exploring more cost-efficient alternatives. A separate tender for the CEB to construct its own battery systems, supported by financing from the Asian Development Bank, recently closed and is now under evaluation. This dual strategy—inviting private investment while fostering state-owned capabilities—signals a comprehensive attempt to balance affordability, reliability, and renewable integration.
Another persistent challenge lies in the grid’s limited visibility into rooftop solar operations. Because small-scale solar systems lack centralized monitoring features, control rooms cannot accurately track sudden production drops caused by cloud cover or rain. This lack of real-time data complicates forecasting and makes it more difficult to balance supply with demand. To address this gap, the CEB plans to roll out 200,000 smart meters across the country. Minister Jayakody stated that approximately 2,000 meters—covering around 650MW of connected capacity—would be installed by March 2026, creating a more transparent and responsive grid.
As Sri Lanka strives to expand its renewable portfolio, the tension between sustainability goals and grid stability continues to grow. Solar grid instability remains a central concern that demands strategic investment, advanced monitoring technology, and regulatory clarity for energy producers. The nation’s ongoing shift toward cleaner power is both promising and challenging, with stability solutions now taking priority in national energy planning. If these initiatives proceed as scheduled, Sri Lanka could enter a more secure and balanced renewable era, significantly reducing the disruptions that have troubled the grid in recent years.