Cyprus power outages: How a communication failure and a fault in the north triggered system protections

Local EACelectricityphotovoltaicsTop News Cyprus power outages: How a communication failure and a fault in the north triggered system protections Revma Xatzilaou Zavallis 1024x577 Relevant News Cyprus power outages: How a communication failure and a fault in the north triggered system protections 30 August 2026 Dionysis Tsirigotis: Turkey is expanding its geopolitical footprint, creating new realities for Cyprus 30 August 2026 Deadly summer storm leaves one dead, injuries and widespread damage across Cyprus 30 August 2026 newsroom 30 August 2026 FacebookXWhatsAppEmailPrintViber Cyprus faced two serious disruptions to its electricity system last week, leaving thousands of consumers without power for around an hour on Friday morning and for around 20 minutes early on Saturday. The first incident, according to information available so far, was caused by a temporary loss of communication between the Distribution Control Centre and photovoltaic parks. The second was triggered by a fault in the generation system in the occupied areas. In both cases, the electricity system responded in the same way. In simple terms, it was forced to cut power to a large number of consumers in order to prevent a wider blackout, which could have had far more serious consequences. The exact source of the problems has not yet been fully identified and remains under investigation. The Sunday edition of Phileleftheros spoke to Haris Zavallis, assistant director of the National Energy Control Centre of the Cyprus Transmission System Operator (TSOC), and electrical engineer and energy consultant Christakis Hadjilaou about what happened. Zavallis explained the events from the perspective of the system operator, saying that the future operation of Energy Storage Systems is expected to provide additional reserves and reduce the impact of similar incidents on consumers. Hadjilaou, however, warned about the Friday incident, saying that a similar disruption during spring or autumn, when conditions may not be as favourable as in summer, could pose serious risks. What went wrong on Friday The more serious of the two incidents occurred at 10.40 am on Friday, when a communication problem developed between large photovoltaic parks and the Distribution Control Centre. Large photovoltaic parks do not simply produce electricity and feed it into the grid without control. Their output is monitored and managed so that the Control Centre knows at any given moment how much energy is being generated from different sources and how much is being consumed. For this reason, photovoltaic parks continuously send production data to the operators. This information allows them to maintain a real-time picture of the electricity system and increase or reduce generation when necessary. The flow of information works as follows: the Electricity Authority of Cyprus (EAC) receives data from photovoltaic parks and transfers it to the Cyprus Transmission System Operator. On Friday, this chain experienced a failure. According to the Transmission System Operator, the communication interruption meant that the production measurements received from photovoltaic facilities were incorrect. The EAC had referred to a temporary loss of telecommunications links between the Distribution Control Centre and photovoltaic parks connected to the network. This was followed by a sudden loss of 165 megawatts of photovoltaic generation, according to public comments made at the time by Zavallis. Authorities explained that, for Cyprus’ electricity system, the loss of 165MW represents a very large amount of power disappearing within a very short period of time. As an indication of the scale, the largest conventional generating unit currently operating in Cyprus is around 120MW. The balance that must always be maintained To understand why this loss of generation led almost immediately to power cuts, it is necessary to explain a basic principle of electricity system operation. Electricity production and consumption must remain constantly balanced. The electricity system can be compared to a set of scales. On one side is all the electricity being produced at that moment by EAC units, photovoltaic systems and other sources. On the other side is the electricity being demanded at the same time by homes, businesses, hotels, factories and other consumers. The two sides must remain almost equal. If the balance begins to shift towards demand, the system comes under pressure. On Friday, 165MW of generation suddenly disappeared from one side of the balance, while consumers continued demanding electricity as normal. If the drop had continued unchecked, the problem could have spread, causing further losses of generation and a chain reaction that could potentially have resulted in a widespread blackout. Power cuts as a protective measure The reason power was cut on Friday was precisely to prevent that scenario. When the system detected the sudden loss of generation, it automatically activated its protection mechanisms and began disconnecting consumer load. In the scales analogy, it removed weight from the demand side until balance was restored. According to Zavallis, the process took place in six stages, with around 140MW of consumer load disconnected in total, equivalent to about 14% of demand at the time. This means the outages experienced by consumers were not the original failure, but a protective measure designed to prevent a much more serious collapse. The system had lost around 165MW of generation and, to restore balance quickly, removed around 140MW of consumption while additional generation was being brought online. Once the system stabilised, consumers who had been disconnected were reconnected. A further question remains: if reserve capacity was available, as Zavallis had said, why was generation not simply increased to replace the lost 165MW? The explanation given was that the issue was one of timing. A sudden loss of such a large amount of power affects the system within seconds. Protection systems must respond immediately to prevent a wider disruption, while increasing generation takes longer. For this reason, load shedding was activated first to stabilise the system while the process of increasing production was underway. Despite a clearer picture now emerging of what happened, a key part of the puzzle remains unresolved: the exact point where the initial failure occurred and caused incorrect data to reach the Control Centre. Initial reports focused on telecommunications connections with photovoltaic parks. However, at the time of writing, the precise point of failure had not been identified. According to the EAC spokesperson, checks carried out by Cyta did not identify a problem with its telecommunications infrastructure. The investigation continues across the entire data transmission chain and involves the telecommunications provider, the company that installed the Control Centre and other involved partners. The connection with the occupied areas The power disruption on Saturday was unrelated to Friday’s incident, according to the Transmission System Operator. The fault occurred in the generation system in the occupied areas. To understand why a problem there affected consumers in the areas controlled by the Republic of Cyprus, it is necessary to note that the two electricity systems are interconnected. Cyprus’ electricity system operates as a single synchronised system consisting of two parts: part A, covering the areas controlled by the Republic, and part B, covering the occupied areas. The electrical connection operates at two points under the framework of confidence-building measures. When generation was lost in the occupied areas on Saturday morning, the balance of the interconnected electricity system was affected. Consumer load shedding was initially activated in the occupied areas. However, because frequency was also affected in the areas controlled by the Republic, automatic protection systems were activated there as well. Around 20MW of consumer load was disconnected in areas controlled by the Republic of Cyprus. Once again, the system carried out the same function as it had on Friday: reducing demand temporarily in order to restore balance. The connection with the occupied areas can, in some circumstances, result in power cuts on one side even when the fault occurs on the other. Nevertheless, it is considered crucial for the security and stability of the electricity system, as it provides greater room for response during serious disruptions and helps prevent a wider blackout. Haris Zavallis: Storage systems will provide greater reserves in future Image Zavallis said the Friday outage was caused, according to preliminary data from the EAC Distribution System Operator, by a temporary loss of communication between the Distribution Control Centre and photovoltaic parks. This resulted in incorrect production data being transmitted to the Transmission System Operator and the inability to control commercial photovoltaic parks, triggering automatic consumer load shedding. He said electricity supply was fully restored within an hour, while the exact causes of the incident remain under investigation by the Distribution System Operator. Regarding Saturday’s incident, Zavallis said it was unrelated to the previous event and was caused by a fault in the network within the occupied areas, which led to a loss of generation in that part of the system. Because the electricity system across Cyprus is synchronised, the fault immediately affected the areas controlled by the Republic as well. Protection systems operated quickly and effectively, activating the automatic consumer load shedding plan to rebalance generation and demand and restore frequency. He said this response was the technically appropriate practice in similar unexpected failures involving conventional generating units or other parts of the electricity network. The future operation of Energy Storage Systems by the Transmission System Operator and private operators is expected to provide increased reserves and reduce the impact of similar incidents on consumers. Christakis Hadjilaou: August 21 incident was a serious warning Image Electrical engineer and energy consultant Christakis Hadjilaou said the incident on August 21 did not reveal an inherent problem with photovoltaic technology itself. Instead, he said it highlighted critical questions about how rapidly increasing photovoltaic penetration is integrated, managed and controlled within Cyprus’ electricity system. Hadjilaou said the incident should not be treated as a simple technical fault that has now been resolved, arguing that it raised issues of prevention, operational readiness, institutional responsibility and accountability. The key question, he said, is not why communication was lost, but why a telecommunications failure developed into such a large loss of photovoltaic generation and ultimately affected consumers. He welcomed the EAC’s announcement that a backup telecommunications connection would be promoted, but questioned why such a measure was being introduced after the outage rather than before it. He also questioned whether backup coverage had already existed and, if so, why it failed to operate. According to Hadjilaou, backup coverage for critical telecommunications infrastructure is not a luxury but a fundamental part of safe electricity system operation. He added that an investigation should examine the entire chain of planning, licensing, control and supervision, involving the Transmission System Operator, the EAC Distribution System Operator, photovoltaic park operators, telecommunications providers and the Cyprus Energy Regulatory Authority. The fact that responsibility may be shared, he said, does not mean that no responsibility exists. Instead, it requires identifying precisely who was responsible for each stage and whether obligations were fulfilled. Hadjilaou said authorities should provide evidence on how close the system came to the limits of safe operation and which protection mechanisms were activated. He also called for an examination of what could happen if a similar incident occurred under different conditions, such as during spring or autumn, with lower demand, higher photovoltaic penetration and a different mix of generating units in operation. The incident should be fully investigated and the findings made public, he said, with specific answers on what happened, which safeguards worked, which failed, who was responsible and what measures would now be taken. If shortcomings are identified, responsibility must also be assigned, he added. Cyprus avoided the worst outcome on August 21, Hadjilaou said, but the incident should be treated as a serious warning rather than as reassurance that the system can withstand similar events in the future. Subscribe to our Newsletter Latest News Dionysis Tsirigotis: Turkey is expanding its geopolitical footprint, creating new realities for Cyprus Deadly summer storm leaves one dead, injuries and widespread damage across Cyprus Sunny weather ahead as temperatures set to rise above seasonal average Limassol businessman, rally driver Dimi Mavropoulos dies in boat disaster off Cape Greco One dead, five rescued in Cape Greco search and rescue operation Storm could push August rain past 700% of average, Kitasweather says Hundreds of weather-related incidents reported as storms batter Cyprus Follow en.philenews on Google News and be the first to know all the news about Cyprus and the world.