In the sun-drenched landscapes of Cyprus, a silent battle is unfolding between the island’s ambitious renewable energy goals and the technical constraints of its isolated power system. A recent study, led by P. Therapontos of the Electricity Authority of Cyprus and the University of Cyprus, published in the journal ‘Solar Energy Advances’ (translated to English from Greek as ‘Progress in Solar Energy’), has shed light on the escalating issue of renewable energy source (RES) curtailments, revealing a complex web of challenges and potential solutions that could reshape the energy sector.
Cyprus, with its abundant sunshine, has rapidly increased its photovoltaic (PV) capacity, reaching 780 MW. However, this rapid growth has led to significant curtailments, with annual rates surging from 2% in 2022 to a staggering 13% in 2024. During low-demand periods, monthly PV curtailment has exceeded 28%, resulting in substantial energy losses and economic impacts. “The primary drivers of these curtailments are system-wide constraints, particularly minimum inertia requirements and ramp rate limitations of conventional generators,” Therapontos explains. “These issues are exacerbated by Cyprus’s seasonal demand variability and the high penetration of PV capacity.”
The study, which analyzed historical data and conducted simulations, forecasts further escalation of curtailments as PV capacity approaches 1 GW by 2027. The increase in high-curtailment days (≥200 MWh) has already surged by 500% from 2022 to 2024, raising concerns about the equity of operational procedures that prioritize curtailing large-scale RES installations first. This approach disproportionately affects stakeholders, potentially stifling investment in renewable energy projects.
To mitigate these challenges, the study evaluates a range of strategies, from infrastructure enhancements to operational measures. One promising solution is the 1 GW HVDC Great Sea Interconnector, which could bolster grid stability and reduce curtailments. Additionally, retrofitting aging plants as synchronous condensers to bolster inertia and deploying energy storage systems (ESS) could significantly alleviate the issue. Therapontos notes, “Deploying 80 MW/240 MWh batteries could reduce curtailments to 10% by 2025.”
Demand-side flexibility, particularly elastic electric vehicle charging, and AI-enhanced forecasting are also identified as cost-effective supplements. However, reducing the minimum stable generation level (MSGL) to accommodate higher RES penetration poses risks of frequency instability. Transient simulations showed critical rate of change of frequency (RoCoF) thresholds exceeding 1 Hz/s during generator outages, highlighting the need for a balanced approach.
The study underscores the necessity of a hybrid approach combining grid reinforcement, ESS deployment, and market-driven demand response. This strategy could align Cyprus’s RES growth with EU decarbonization targets while ensuring grid reliability. As the energy sector grapples with similar challenges worldwide, this research offers valuable insights and potential pathways for other isolated grids facing RES curtailments.
The findings from Therapontos and his team could influence future developments in the field, encouraging a more nuanced approach to grid management and renewable energy integration. By addressing technical constraints and leveraging innovative solutions, Cyprus and other regions can pave the way for a more sustainable and resilient energy future.
