hydroelectric hy‧dro‧e‧lec‧tric [ˌhaɪdrəʊ-ɪˈlektrɪk◂ ǁ -droʊ-] adjective
involving the use of water power to produce electricity:

• The dams produce most of the country's hydroelectric power.

— hydroelectricity noun [uncountable] :

• Oil was abandoned in favour of hydroelectricity and nuclear power.

* * *

hydroelectric UK US /ˌhaɪdrəʊɪˈlektrɪk/ adjective
NATURAL RESOURCES producing electricity by using the power of fast moving water, such as from a river: »

hydroelectric power

hydroelectricity noun [U]

More than 80% of the power generated in the Northwest comes from hydroelectricity.

Financial and business terms. 2012.