The Ermoupolis Desalination Plant is a major water-infrastructure project designed to strengthen the long-term water security of Syros. With the planned expansion, the plant's capacity will increase to 10,000 m³/day of potable water, helping the island respond to growing demand and the pressures of seasonal water scarcity. What makes the project especially forward-looking is that it combines advanced desalination with renewable energy, through a new 2.7 MW photovoltaic park, creating a more sustainable model for water production on a Greek island.
Designing a next-generation desalination system
For this project, NAMA contributed to the design of an upgraded desalination facility that combines modern treatment technology, supporting infrastructure and on-site renewable energy production.
The project includes:
- expansion of the plant to 10,000 m³/day of drinking water,
- a new submarine seawater intake pipeline and intake pumping system,
- pretreatment with pre-filtration and ultrafiltration (UF) membranes,
- a reverse osmosis (RO) system with high-pressure pumps, energy recovery and membrane cleaning units,
- post-treatment for remineralisation, pH correction and chlorination,
- potable water storage and pumping for connection to the existing distribution network,
- a new submarine brine outfall pipeline and chemical neutralisation unit,
- full automation, measurement and control systems,
- new electrical infrastructure, substation, utility networks and supporting site works,
- a 2.7 MW photovoltaic installation over approximately 53,000 m² to help cover the plant's energy needs.
Strengthening water resilience on an island under pressure
The value of the project goes far beyond the plant itself. On an island like Syros, where freshwater resources are limited and demand rises sharply in the summer months, desalination has become a critical part of everyday life. Expanding the plant helps secure a more reliable water supply for residents, businesses and visitors, while reducing the vulnerability of the island's water system during peak-demand periods.
Just as importantly, the integration of solar energy improves the environmental profile of the project. Desalination is essential for many islands, but it is also energy-intensive. By pairing water production with photovoltaic generation, the project supports a cleaner and more efficient operating model, reducing energy costs and making better use of Syros' strong solar potential.
Its wider environmental and social impact includes:
- improving the reliability of potable water supply across the island,
- strengthening resilience during high-demand summer periods,
- reducing pressure on limited local water resources,
- supporting public health, everyday life and tourism activity,
- lowering the energy footprint of desalination through on-site renewable power,
- promoting a more sustainable and climate-aware model of island infrastructure.
By combining desalination and solar energy in one integrated project, the Ermoupolis Desalination Plant points toward a more resilient future for Syros — one where water security and sustainability can advance together.
