How to switch to renewable energy

Generating hydroelectic power


Hydroelectric power uses water flowing through a turbine to drive a generator which produces electricity. The faster the water is flowing and the bigger the drop, the more electricity will be generated. You can either:

  • use a water wheel or a turbine for run-of-the-river schemes which use the natural flow of the water to generate hydroelectricity
  • store water in a reservoir to be passed though an underwater turbine at pressure

Hydropower is site specific and you should choose a scheme that suits your site and needs. The payback period for a small system is likely to be over ten years.

Advantages of hydroelectric power

  • Hydroelectric power systems are very efficient and convert 70-90 per cent of water energy to electricity.
  • Generating hydroelectric power produces no waste.
  • Once installed, hydroelectric power systems should run for many years.
  • Hydroelectric power is a well-developed technology.

Disadvantages of hydroelectric power

  • You may need an additional power supply available to compensate for seasonal variations in water flow.
  • Significant development work is required to install small-scale hydroelectric energy equipment.
  • You must get planning permission and may need other authorisations such as a water abstraction and/or impoundment licence.
  • Hydroelectric power is highly site specific.
  • Hydroelectric power systems require regular maintenance.

Apply for environmental authorisations

Even a small hydropower plant can cause water pollution, disrupt fish migration and cause ecological damage if badly designed and built.

If you want to develop a micro-hydro power plant, you will need the correct authorisation from the Northern Ireland Environment Agency (NIEA). To apply, you must submit supporting information including:

  • a detailed description of the scheme design
  • the scheme location
  • the generating capacity of your scheme
  • the minimum and maximum volume of water you will abstract to generate power
  • river flow where abstraction stops
  • your scheme's impact on wildlife, river beds and river navigation
  • how you will reduce the impact on fish migration, eg providing fish passages and screens

To develop a hydropower scheme you will need an abstraction or impoundment licence from NIEA if your scheme uses more than 20 cubic metres of water per day.

If you place structures in any waterway that are likely to affect its drainage you must have consent from DfI Rivers.

If you abstract water for your hydropower development you need to consult with the Department of Agriculture, Environment and Rural Affairs (DAERA) to make sure your scheme does not damage fisheries.

If your scheme is in the Foyle or Carlingford catchment areas you must notify the Loughs Agency.

Apply for planning permission

If you want to build a hydropower plant you must apply for planning permission from your local divisional planning office at the same time you apply to NIEA.

Generating renewable energy in conservation areas

If you want to develop a site for hydropower that is in a conservation area or protected area, you must inform NIEA.

Protected areas can include:

  • areas of special scientific interest
  • national parks
  • areas of outstanding natural beauty
  • special areas of conservation
  • special protection areas

Find out if your proposed site is in or near a protected area by using these online interactive maps.

If your site has archaeological or architectural interest you must inform NIEA.

Carry out an Environmental Impact Assessment (EIA)

If your hydropower generating capacity is above 500 kilowatts or if your development is in a protected area, you will need to carry out a formal EIA for your scheme. You must submit this to NIEA and the your local council planning office.

Find more information about EIAs.