Hydro-electricity, has been used since the late 1800s and generates the greatest energy yield of all the renewable energy technologies. Due to the climate, vegetation and mountains in Northern Ireland, most rivers are fed by precipitous water. This refers the water and rain which runs from high ground.

Power generation of hydro systems depends on two factors: the height the water falls (head) and the volume of water available (flow). Flowing water is diverted from a given point in a river via a channel or “race” which may be piped to a turbine located downstream, where it passes through the turbine and drives a generator.

Costs for installing a hydro turbine can be significant but an appropriately sized and maintained hydro turbine can produce electricity efficiently for over 100 years. The feasibility of the turbine will depend on the site and how much civil work is required. For instance a weir or water channelling may be necessary. Utilising an old mill with an existing mill race will reduce capital costs.

Other water users may raise concern about any diversion of water from a river. It is important to consider their needs and liaise with any such users as fishing societies or fisheries to assure them of plans to introduce any hydro scheme sensitively. An important consideration and in many cases a regulatory requirement is to provide a fish pass to protect fish stocks on a river. A water abstraction licence will also be required.