Hydro power
Hydroelectric/hydro 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 hydropower.
- store water in a reservoir to be passed through an underwater turbine at pressure.
Hydro power is site specific and you should choose a scheme that suits your site and needs.
Advantages of hydro power
- Hydro power systems are very efficient and convert 70-90 per cent of water energy to electricity
- Generating hydro power produces no waste
- Once installed, hydro power systems should run for many years
- Hydro power is a well-developed technology
Disadvantages of hydro 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 hydro power equipment
- You must get planning permission and may need other authorisations such as a water abstraction and/or impoundment authorisation
- Hydro power is highly site specific
- Hydro power systems require regular maintenance
Apply for environmental authorisations
Even a small hydro power 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) or the Scottish Environment Protection Agency (SEPA).
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, riverbeds and river navigation
- how you will reduce the impact on fish migration, e.g. providing fish passages and screens
Hydro power schemes in Northern Ireland
To develop a hydro power scheme, you will need to apply for an abstraction or impoundment licence from the NIEA.
There is a fee associated with this activity if your scheme uses more than 20 cubic metres (m3) of water per day
If your scheme uses between 10m3 and 20m3 there is no fee however, you must still complete an application and submit to the NIEA.
If you place structures in any waterway that are likely to affect its drainage you must have consent from the Rivers Agency.
Northern Ireland: Department for Infrastructure Rivers
If you abstract water for your hydro power development, you need to consult with the Department for Infrastructure (DfI) 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.
Hydropower schemes in Scotland
In Scotland, water abstractions and associated impoundments for hydro power are regulated by SEPA under the Environmental Authorisations (Scotland) Regulations (EASR). Depending on the nature and scale of the activity, authorisation may be provided through:
- General Binding Rules (GBRs)
- Registrations
- Permits
The abstraction of inland water for hydropower where the total daily abstraction exceeds 50 m³ per day requires a Permit. This permit also covers the construction, modification or operation of any associated impoundment.
Additional authorisations may be required.
SEPA: EASR permit for the abstraction of inland water for hydro power of more than 50m³ per day
SEPA: EASR surface water and groundwater abstraction authorisations
SEPA: EASR Impoundment authorisations
Apply for planning permission
In Northern Ireland, if you want to build a hydro power plant you must apply for planning permission from your local divisional planning office at the same time you apply to the NIEA.
In Scotland, hydro power schemes with a generating capacity of 50 megawatts (MW) or less are normally determined by the local planning authority. Schemes with a generating capacity of more than 50MW require consent from Scottish Ministers through the Energy Consents Unit
You must apply for planning permission at the same time you apply to SEPA.
Generating renewable energy in conservation areas
In Northern Ireland, if you want to develop a site for hydro power that is in a conservation area or protected area, you must inform the NIEA.
Protected areas can include:
- areas of special scientific interest
- areas of outstanding natural beauty
- special areas of conservation
- special protection areas
NIEA: Natural Environment Map Viewer
If your site has archaeological or architectural interest, you must inform the NIEA.
In Scotland, NatureScot may need to be consulted where a hydropower proposal could affect protected areas, protected species or designated sites.
Protected areas can include:
- sites of special scientific interest
- national parks
- national scenic areas
- special areas of conservation
- special protection area
NatureScot: Sitelink interactive map of protected sites
If your site has archaeological or historic environment interests, you should consult Historic Environment Scotland (HES)
Carry out an Environmental Impact Assessment (EIA)
A hydro power scheme may require Environmental Impact Assessment (EIA) screening by the planning authority. Whether a full EIA is required depends on the size, location and potential environmental impacts of the proposal.
You must submit an EIA to:
- the NIEA and your local planning authority in Northern Ireland
- SEPA and your local planning authority in Scotland
NIEA: Environmental Impact Assessments (EIA)
Scottish Government: EIA Planning circular
Further information
The Carbon Trust: Renewable energy generation
The Microgeneration Certification Scheme: Accredited installers