February 18, Colombo (LNW): The Ceylon Electricity Board (CEB) has outlined a series of immediate and long-term actions to address grid stability concerns following the nationwide power failure that occurred on 9 February 2025.
The incident, which took place at 11.13 a.m., left much of Sri Lanka without electricity and caused significant disruption to daily life.
In response, the CEB has assured the public that corrective steps are already underway to ensure a more stable and resilient national grid.
The power failure was traced to a disturbance at the 33kV Panadura Grid Substation, which led to a rapid voltage drop throughout the electricity network.
At the time of the incident, over half of the nation’s electricity demand was being met by solar photovoltaic (PV) generation, with additional power supplied from the Lakvijaya Power Plant in Norochcholai and various hydropower stations.
However, the high share of non-synchronous solar PV generation left the grid vulnerable to instability.
The CEB explained that the lack of synchronous power generation contributed to low system inertia, making the grid prone to faults.
As the disturbance triggered an imbalance between supply and demand, this led to cascading disconnections and, ultimately, the complete loss of power.
Several key factors contributed to the magnitude of the outage. Firstly, the high penetration of solar PV, combined with low grid inertia, left the system exposed to voltage and frequency disturbances.
Secondly, the sharp voltage drop caused many solar PV systems to automatically disconnect, exacerbating the instability.
Additionally, the automatic response by the Norochcholai Power Plant to the disturbance—while preventing potential internal damage—resulted in further strain on the grid.
The power failure was also influenced by the “Sunny Sunday” effect, where a low weekend demand combined with high solar generation created an unstable situation.
With industries and commercial customers offline, the grid was operating with reduced demand and reduced inertia, heightening its susceptibility to such disturbances.
In the wake of this event, the CEB has implemented a number of urgent measures aimed at stabilising the national grid and preventing future outages.
These include ensuring that more synchronous generators are maintained at a minimum generation level and operating selected gas turbines in synchronous condenser mode at critical locations to support voltage stability.
The CEB has also curtailed the generation of ground-mounted solar PV systems during low-demand periods, when necessary, to reduce the risk of grid instability.
Looking ahead, the CEB is pursuing medium-term strategies to further improve grid reliability.
This includes adjusting rooftop solar PV inverter settings to prevent unnecessary disconnections during minor disturbances and introducing special industrial tariffs to encourage industries to operate during off-peak hours.
In addition, the CEB is promoting solar installations paired with Battery Energy Storage Systems (BESS) to improve grid resilience and stability.
The CEB also outlined several long-term solutions to modernise the grid and better integrate renewable energy sources. Key initiatives include deploying grid-forming inverters with BESS to provide synthetic inertia and stabilise frequency fluctuations.
Furthermore, the CEB is working to install emergency backup generators at the Norochcholai Power Plant to ensure rapid reconnection in the event of future disconnections.
The Maha Oya Pumped Hydro Project, a 600 MW storage facility, is also set to play a crucial role in enhancing grid flexibility and energy security.
Additionally, the CEB is advancing investments in Smart Grid technology to improve real-time monitoring and control of renewable energy inputs.
The CEB concluded by acknowledging the significant inconvenience caused to the public by the power outage and reaffirming its commitment to providing a resilient, reliable, and future-proof electricity supply.
