Kythnos: A Pioneer Island in Decarbonisation Projects

Coordinated by the DAFNI Network of Sustainable Greek Islands and in collaboration with the National Technical University of Athens and the Municipality of Kythnos, the Kythnos Smart Island (KSI) project has transformed the island into a living laboratory for implementing a holistic strategy to upgrade infrastructure and public spaces while strengthening the local economy. The project was funded by Siemens as part of the Settlement Agreement with the Hellenic Republic.

A Model for Sustainable Innovation

Kythnos has become a real-world example of sustainable development, seamlessly integrating technological advancements with social innovation. The KSI project has delivered significant results that can be replicated on other islands, laying the foundation for a circular economy. The island’s transformation began with extensive renovations to the off-grid microgrid in Gaidouromantra, which received key upgrades including the installation of heat pumps, photovoltaic (PV) systems, and battery energy storage solutions. These improvements now generate approximately 39 MWh of clean energy annually, reducing the island’s reliance on traditional energy sources.

In addition, municipal buildings received energy-efficient upgrades, while street and public space lighting were redesigned and retrofitted to improve energy efficiency. This focus on clean energy and efficiency extended to the installation of three solar PV plants (totalling 25 kW) and a 30 kWh energy storage unit, which now produces renewable energy that supports the island’s needs and reduces its environmental impact.

The project also addressed key infrastructure challenges. Three new desalination plants were installed, and the water distribution network was upgraded to reduce losses and improve efficiency. Waste management was similarly revamped, with the introduction of a door-to-door recyclable waste collection system using electric vehicles (EVs). A prototype centre for bulky and green waste management was also developed, ensuring that Kythnos’ waste is handled sustainably.

As part of its sustainability drive, Kythnos prioritised electric mobility. The island now features a public and private EV charging network established in collaboration with local hotels and restaurants, completing 865 charging cycles over an 8-month period and saving 9,639 kWh of energy. This effort contributes to reducing the island’s carbon footprint and enhancing its green credentials. The local marina was also upgraded into a smart and green facility, further enhancing Kythnos’ sustainability and improving its appeal as a model for other coastal regions.

Innovative Energy Solutions: RE-EMPOWERED and WIRE-K Projects

Building on the success of KSI, the RE-EMPOWERED project (running from July 2021 to December 2024) has brought further innovation to the island’s energy system. The Gaidouromantra microgrid has been enhanced with five ecoTools, which optimise energy use, increase renewable energy capacity, and promote sustainability. Notably, tools like ecoMicrogrid and ecoPlatform have allowed for better integration of renewable energy, while the installation of the ecoMonitor at Merichas High School tracks air quality and contributes valuable data to help combat air pollution.

Furthermore, the Wind Turbine Repowering in Kythnos (WIRE-K) project, supported by NESOI, has contributed to the island’s renewable energy expansion. The study concluded that the replacement of existing turbines with a 665 kW wind turbine and a 390 kW Battery Energy Storage System (BESS) would increase the island’s renewable energy share to 31%. The repowered turbine will generate 5,586 kWh annually, significantly boosting Kythnos’ energy autonomy.

The Kythnos Smart Island (KSI), RE-EMPOWERED, and WIRE-K projects have led to significant achievements. The Gaidouromantra microgrid’s CO2 emissions and costs have been reduced by 66% and 56%, respectively. The installed wind turbine generates 5,586 kWh annually, and solar PV curtailment has dropped by 18%. These results showcase Kythnos as a model of sustainability, offering valuable lessons for other islands and regions pursuing green, renewable energy solutions.

This best practice is extracted from our publication ‘Sustainable Regions in Action‘. Discover more best practices here!