Background and context

The water treatment facility in Tomar, Portugal, faced growing challenges related to rising energy costs, regulatory efficiency targets, and high electricity dependency. To address these issues, a strategic approach was developed to optimize energy use, improve operational efficiency, and integrate renewable energy sources within the facility.

Approach

The initiative centred on implementing an Energy Management System (EMS) compliant with ISO 50001, optimizing treatment and pumping processes, and installing two mini-hydro power generation systems to reduce reliance on grid electricity. Additionally, energy-efficient equipment and process automation were integrated to enhance overall system performance. Key stakeholders included EPAL, AdP – Águas de Portugal, and Portuguese government regulatory agencies, which played essential roles in policy compliance, funding, and technical expertise. Implementation began with an in-depth energy audit to identify major energy-consuming processes, followed by the formation of a multidisciplinary energy management team. Process optimizations targeted rapid mixing, backwash pumping, sludge handling, and lighting efficiency. The installation of two hydroelectric turbines (140 kW and 1.4 MW) allowed the facility to generate renewable energy, while advanced monitoring tools enabled real-time tracking and optimization of energy consumption.

Outcomes and impacts

The project resulted in a 25% reduction in total energy consumption, achieving energy self-sufficiency through hydroelectric power generation. Additionally, greenhouse gas emissions were significantly reduced, contributing to environmental sustainability. The project also enhanced operational efficiency and reliability of the treatment facility, reduced dependency on grid electricity, and lowered operational costs. Moreover, it strengthened institutional capacity for energy management in the water sector, setting a benchmark for other utilities.

Lessons learned

The initiative successfully demonstrated that water treatment facilities can achieve energy self-sufficiency through innovative management and renewable energy integration. Cross-departmental collaboration was key to driving process innovation, and achieving ISO 50001 certification reinforced the commitment to sustainable practices. However, challenges such as managing hydraulic transients when integrating hydroelectric turbines required careful risk mitigation. The methodology and technologies used in Tomar can be replicated in other water utilities, provided there is strong leadership, technical expertise, and regulatory support. This model offers a scalable solution for improving energy efficiency and sustainability in the water sector worldwide.