Hydropower Frequently Asked Questions
How much power can I generate?
The amount of power a site can generate depends on how much water there is and how great a fall there is. If your site is an old water mill then it was built because there was water power potential at that location, so there is a good chance you will be able to generate.
Many sites will produce enough power for a few houses, but there are some sites on larger rivers, and some mountain burns where there is the potential to supply hundreds of homes.
For how long is the Feed-in-Tariff - FiT guaranteed?
The FiT for hydro schemes is guaranteed for 20 years from the date of commission. For more details about FiTs for hydropower you will need to go to the Department for Energy and Climate Change [DECC] web site at this link - www.gov.uk/government/organisations/department-of-energy-climate-change
What is the current export level?
The export level is currently between 4p and 6p
Is inflation added to both FiT and export level each year?
Yes both the FiT and export tariff are index linked.
A grid connection must be arranged with your local Distribution Network Operator (DNO). Network capacity is scarce in certain parts of the country and should be assessed and reserved as early as possible to prevent delays to any project.
The costs of grid connection are site-specific, but the main variables influencing cost are: connection voltage; physical location and access to the network; network capacity and availability; upgrade requirement, if any; and generation technology.
The costs vary between DNOs and also depending on the connection voltage. Design fees vary between a few hundred pounds for small low voltage connections to several thousand for connections to the 33 kV network.
The DNO has a 3 - month period to design and cost an appropriate connection. The DNO will also identify the contestable and non-contestable works.
Once the design is complete, contracts are signed. In addition, Use of System Agreements will have to be signed for the export of electricity to the network.
How much does a hydropower system cost to build?
This is very site dependant, but the cost is very rarely less than £35,000. As a very rough rule of thumb it might be useful to think of £7,000 per kW capacity for smaller sites, or £3,000 per kW capacity for a larger system, but there is huge variation from one site to another.
What are the running costs for a scheme?
The main costs will include the following:
- Business rates
- Operation and Maintenance
- Replacement of key parts after approximately 10 -15 years
The capital costs sound high, what is involved?
The capital costs will include the following:
- The turbine and all the drives, generators and valves
- Pipe costs and welding works
- Civil works to create the intake, screens, pipeline, and the turbine house
- Electrical works within the turbine house plus transformer if required
- Connections costs including any upgrading of the Grid if required
- Any new access tracks and routes to the abstraction point
- Design and licence fees
Would business rates be charged against a scheme?
Yes, unless it is seen as a domestic installation
Can I generate electricity from a fast flowing river without a fall?
In theory this is possible but the amount of power available is very small in comparison to sites where the water drops.
How much income will my scheme provide?
A scheme might be designed to operate on average at half of its peak output. So a 20kW scheme might produce 10kW on average. Throughout a year that is 87,600kWh. Under the Government’s clean energy cash back scheme this would typically be worth around £21,000 per year. For a 40kW scheme these numbers should be doubled. For more information see DECC’s website:
Are there grants available for hydro schemes?
Occasionally yes, but normally no. There is no UK-wide general hydropower grant scheme. Schemes that are available change too frequently to be covered here.
Can I generate using my old water mill?
Normally yes, as long as it still has a water supply and somewhere where the water falls (with space for the installation of a turbine), it is probably possible.
How much water do I need?
The more water is available, the higher the power potential of the site. It is important to remember that it will rarely be appropriate to use all of the water at a site for ecological reasons. The amount of water needed for a certain amount for power depends on far it falls, so if the water supply is only a small stream but it can be harnessed high up a hillside, there might still be a significant amount of power available.
Will my scheme need a license or planning permission?
Normally one or more license will be required from the Environment Agency in England, SEPA in Scotland and NRW in Wales. Planning permission is also often required as well. We would recommend consulting the local authority and EA/SEPA/NRW as soon as the technical viability of a project has been established.
How do I know who to go to for advice?
With hydropower there is no standard solution. The best design for a site is often not obvious. It is important to take advice at an early stage from someone with experience and a good track record. Ask for references or information on working installations – hydropower schemes should last for a long time. The BHA is a very useful source of information.