IEA (2019), Tracking Power, IEA, Paris https://www.iea.org/reports/tracking-power-2019
Hydropower additions decreased by 19% in 2018, despite the commissioning of large-scale projects in China and Brazil. Observed growth is 54% below the 43 GW of capacity commissioned in 2013 when global additions peaked.
Hydropower remains the largest renewable electricity technology by capacity and generation. Although growth prospects for new hydropower capacity in next 5 years remain strong (121 GW), they are not sufficient to place hydropower generation fully on track to reach the Sustainable Development Scenario (SDS) level.
In the SDS, hydropower generation expands by 2.5% per year until 2030, meaning that capacity additions need to accelerate to return to the record level of 2013 by 2030. Instead, capacity expansion has been losing speed. This downward trend is expected to continue due mainly to less large-project development in China and Brazil, where concerns over social and environmental impacts have restricted projects.
Meanwhile, deployment in India, Africa, and Southeast Asia accelerates in response to new demand, untapped resource potential, and attractive economics to improve electricity access affordably. However, in the absence of policy action, this growth will not be enough to compensate for slower expansion in China and Brazil.
While hydropower is a mature power generation technology, with high energy payback ratio and conversion efficiency, there are still many areas where small but important improvements in technological development are needed. Work is underway to identify and apply new technologies, systems, approaches and innovations, including experience from other industries, that have the potential to make hydropower development more reliable, efficient, valuable and safe. Improvements along the lines of those made in the last 30 to 50 years will also need to continue, though with smaller incremental benefits: mainly in physical size, hydraulic efficiency and environmental performance.
Dams have a high social and environmental cost, heavily disrupting ecosystems and populations where they are developed. Alternatives that do not require damming or resettlement of populations would help reach SDS levels.
The cost of civil works associated with new hydropower project construction can be up to 70% of total project costs, and their social and environmental impacts can be considerable, so improved methods, technologies and materials for planning, design and construction have considerable potential.