Background and Objectives

Background

Hydropower plays a key role in the transition to a low-carbon electricity system, offering renewable generation, storage, and flexibility. To meet future energy needs, increasing production is essential—not only through new projects, but also by better using the vast potential already embedded in existing water infrastructure. Task 16 focuses on these Hidden and Untapped Hydropower Opportunities (HUHO).

Hidden hydro refers to unused potential in infrastructures not originally built for electricity generation. This includes non-powered dams and weirs, drinking water and wastewater networks, irrigation canals, ship locks, environmental flow outlets, tailrace channels, old mills, desalination facilities, and industrial cooling or process-water systems. Many such installations create hydraulic head or pressure that is currently dissipated without recovering energy. Equipping them with suitable technologies allows clean electricity production with limited environmental or social impact, since major civil works already exist.

Untapped hydro concerns opportunities within existing hydropower plants. Many facilities can significantly increase production, efficiency, or operational flexibility through refurbishment, modernization, or redesign. Examples include upgrading electromechanical equipment, improving waterways, enhancing control systems, integrating variable-speed units, or using advanced materials that reduce losses. These actions can extend asset life, increase annual generation, and improve grid services.

HUHO projects offer several advantages. They typically involve lower investment than greenfield developments, rely on existing structures, and often require fewer environmental assessments. They also strengthen local energy resilience, support rural electrification, and improve the overall efficiency of water management systems. When deployed at scale, numerous small and medium projects can collectively make a substantial contribution to renewable energy targets.

Identifying such opportunities remains challenging because the relevant infrastructures are diverse and managed by many different actors. Their hydropower potential is often undocumented, making it effectively “hidden.” Advances in geospatial tools, digital inventories, data sharing, and analytical methods now enable more systematic identification and prioritization of sites.

Task 16 aims to clarify the scope of HUHO, promote best practices, highlight successful examples, identify barriers and enabling conditions, and outline research and innovation needs. By encouraging the sustainable development of hydropower at existing infrastructures, Task 16 supports global energy objectives while promoting efficient, low-impact use of water resources.