An end to PV curtailments is coming – just not yet

Situation should improve after storage battery system is installed next yearA contract signed last month for a large-scale, centrally managed storage batteries system is anticipated to be followed by other such projects, the Cyprus Mail is told, as the island gradually transitions to accommodate a growing penetration of renewables in the energy mix. Back in June the Transmission System Operator (a state entity) and the Cyprus Telecommunications Authority (a state-run organisation) entered into a contract to deploy storage batteries. The €50 million project is expected to see the batteries delivered in January 2027 and installed within two to three months, allowing them to enter operation by the summer of that year. It covers 120 MW of centralised storage capacity to be managed by the Transmission System Operator (TSO). The storage systems are intended to capture excess renewable electricity during periods of overproduction and release it when demand rises, helping to reduce the controversial – and highly unpopular – curtailments currently imposed on solar generators across the island. The project involves installing and operating three battery energy storage systems, located at transmission substations – one in Nicosia, one in Paphos and one in Larnaca. The locations were selected so the storage systems can be directly connected to the transmission system. Why was CyTA involved? First, because in March this year parliament had green-lit legislation allowing the telecoms company to expand its activities into the energy sector. During a hotly debated session at the House plenum, lawmakers passed an amendment restricting CyTA to green energy without conventional fuel production, setting up direct competition with the Electricity Authority of Cyprus (EAC). Second, because for this particular 120 MW battery project, CyTA partnered up with Huawei. The latter will provide so-called Smart Battery Energy Storage Systems (Bess) which utilise AI to optimise, automate and monitor energy storage. Algorithms predict weather patterns, solar generation and facility demand to dictate exactly when to charge – for example during low-cost or peak solar hours – and when to discharge. We reached out to the EAC, asking what’s next, and also the relevance of battery storage to the grid in general. In an emailed response, the organisation’s generation unit said battery storage energy systems “are expected to play a key role in the transition of Cyprus towards a cleaner, more sustainable and resilient electricity system”. “Their importance is particularly significant because the Cyprus power system is electrically isolated and is not currently interconnected with neighbouring countries. As a result, the electricity system must continuously maintain the balance between generation and demand using only domestic generation resources.” Over the past few years, said the EAC, Cyprus has experienced a rapid increase in electricity generation from renewable energy sources, particularly photovoltaic systems. Since solar generation is highly dependent on weather conditions and peaks during the middle of the day, there are periods when renewable electricity production exceeds the amount that the power system can safely absorb. Absent sufficient storage or interconnections with neighbouring electricity markets, part of this renewable generation has to be curtailed to ensure the secure and reliable operation of the power system. “Battery storage provides the flexibility needed to address this challenge,” the EAC stated. During periods of high renewable generation and lower electricity demand, batteries can store surplus energy that would otherwise be curtailed. This stored energy can then be discharged during the evening peak or at other times when renewable generation decreases and electricity demand remains high. In this way, storage helps shift renewable energy from periods of generation surplus to periods of higher demand, improving the overall utilisation of clean energy. Nevertheless, the state-run organisation stressed, the role of battery storage extends well beyond reducing interruptions or curtailments affecting household photovoltaic systems. At system level, battery storage enhances grid stability by providing fast-response services that help maintain the balance between electricity generation and consumption. It can contribute to frequency regulation, reserve capacity, voltage support, improved system flexibility and increased operational reliability. These services become increasingly important as the share of variable renewable energy sources continues to grow. Also, battery storage reduces the need to rely on conventional generation units solely for balancing purposes, thereby improving the efficiency of the electricity system and supporting the country’s decarbonisation objectives. It also facilitates the integration of additional renewable energy projects in the future, allowing a greater share of clean electricity to be accommodated while maintaining the high standards of security and reliability required for the operation of the power system. In recent years, Cyprus has experienced a rapid increase in electricity generation from renewable energy sources We next asked what other large-scale battery storage projects are currently in the pipeline. The EAC is undertaking a major utility-scale battery storage project at the Dhekelia power plant. The project consists of an 80 MW/160 MWh battery energy storage system (Bess), making it one of the largest battery storage installations currently being developed in Cyprus. “The Dhekelia Bess forms part of the EAC’s strategy to modernise the electricity system and facilitate the transition to a low-carbon energy sector. Once commissioned, the system will provide fast-response balancing services, improve frequency stability, enhance operational flexibility and enable greater integration of renewable energy sources into the national electricity grid. By storing excess renewable electricity during periods of high generation and supplying it back to the grid during periods of increased demand or reduced renewable output, the project will contribute to reducing renewable energy curtailments and improving overall system efficiency.” According to the state-run power utility, this project is currently at the early stages of construction and is expected to become “an important asset” in supporting the secure and reliable operation of the electricity system as renewable energy penetration continues to increase. Regarding future or coming ventures, the EAC said only that “a number of potential projects are currently at different stages of development” – including preliminary planning, engineering design, feasibility studies, licensing, environmental assessment, regulatory approvals and other preparatory activities. The scale, configuration and implementation of each project will be determined according to the operational needs of the electricity system and the applicable regulatory framework. In terms of power output/production, is there some ‘cap’ from renewable energy that the grid in Cyprus can take? The EAC said there’s no hard-and-fast number one can quote. “The capability of the grid to absorb renewable generation varies continuously according to real-time operating conditions, including electricity demand, weather conditions, network constraints and the level of conventional generation that must remain online to provide essential system services and ensure security of supply.” In practical terms, the amount of renewable generation that can be accommodated also varies seasonally. During the summer months, when electricity demand is high due to air-conditioning loads, the system can generally absorb substantially higher levels of renewable generation, typically in the range of 700-900 MW under favourable operating conditions. During the spring and winter, particularly on weekends and public holidays when demand is lower, this may drop to approximately 350-550 MW. These figures are indicative only and vary depending on the prevailing operating conditions. When renewable generation exceeds the level that the system can safely accommodate, curtailments may become necessary to maintain the balance between electricity generation and demand and to preserve the stability and reliability of the electricity system. The practical maximum amount of renewable energy that the Cyprus electricity system can safely hold will continue to increase through investments in battery energy storage systems, reinforcement of the transmission and distribution networks, advanced grid management technologies, greater demand-side flexibility and, in the longer term, electrical interconnections with neighbouring countries.