Navigation path

Hydropower

© Shutterstock

Hydropower is an extremely flexible technology for power generation. Hydro reservoirs provide built-in energy storage, and the fast response time of hydropower enables it to be used to optimise electricity production across grids, meeting sudden fluctuations in demands.

However, large scale hydropower projects can be controversial because they affect water availability down stream, inundate valuable ecosystems and may require the relocations of populations. Despite being a mature technology, in comparison with other renewable energy sources, hydropower has still a significant potential. New plants can be developed and old ones upgraded, especially in terms of increasing efficiency and electricity production as well as environmental performance. In particular, the development of low-head or very low-head small hydro plants holds much promise.

A Small Hydro Power Plant (SHP) is not simply a reduced version of a large hydro plant. Small hydro plants generate electricity or mechanical power by converting the power available in flowing waters in rivers, canals and streams with a certain fall (termed the ‘head’) into electric energy at the lower end of the scheme, where the powerhouse is located. The power of the scheme is proportional to the flow and to the head. Small hydropower schemes are mainly run off-river with no need to create a reservoir. Because of this fact, small hydropower systems can be considered an environmentally friendly energy conversion option, since they do not interfere significantly with river flows and fit in well with the surroundings. The advantages of small hydropower plants are numerous and include grid stability, reduced land requirements, local and regional development and good opportunities for technologies export.

Even if there is no international consensus on the definition of SHP, a capacity of 10MW total is generally becoming accepted in Europe and is supported by the European Commission and the European Small Hydropower Association.

Read more about: