Hydro Electricity Generation
What is a
Hydropower System
OK, we’ve covered solar power and wind turbines so, to make a full set we need to talk about domestic hydropower systems but, unlike the sun and the wind, this won’t be an option for the vast majority of us so we’re not going to go into great detail on this one.
Rivers and stream flow downhill and hydropower systems and tap into this downhill flowing water and convert this energy via a turbine which drives a generator, into usable electricity.
Obviously you’re going to need access to an appropriate watercourse and that needs to have a combination of two key factors:
- a good flow: how much water is flowing down the river per second
- head: the difference in height over a reasonably short distance
It’s also important to maintain these factors for as much of the year as possible (dry summer months can have a major effect on may watercourses).
The amount of electricity a system generates also depends on how efficiently it converts the power of the moving water into electrical power.
Hydropower Example
How does a hydropower system work?
Flowing water has potential energy that can be harvested as it flows downhill. The faster the flow and the greater the drop the more power can be generated.
To keep things very basic and simple – the flowing and dropping water is channelled into and then sent downstream through a pipeline where it passes through a turbine before returning back into the water source.
The turbine (of which there are various different types to best suit the watercourse) will then convert this potential energy into kinetic energy which is then used to drive a generator which, in turn, creates electricity which can be used or fed into the grid.
Are there different types of hydropower systems?
There are a number of different types but all work on the same principle – different types of turbines designed to optimise the conditions specific to a watercourse and hence work as efficiently as possible.
Seek professional advice as to the best solution for you.
How much electricity will a hydropower system generate?
This is a difficult one to answer as it depends on the size of the system, the average flow, the head hight and how often water flow conditions remain optimum.
In theory it could generate 24 hours a day, 7 days a week and 365 days a year and if the water course allows for this it’s going to prove very efficient as a means of electricity generation.
There’s a formula you can use:
Flow rate (in litres per second multiplied by head (in metres) multiplied by 10 (acceleration as a result of gravity) then divide the answer by 2 to take into account times when the system won’t work optimally.
The answer you’re left with will give you an estimate of the potential power generation in watts.
To give you a better idea – a 5KW hydropower system which works properly for about half the year will generate in the region of 22,000 kwh.
How much will a hydropower system cost?
The cost of buying and installing a hydropower system very vastly depending on the size and type of equipment itself and, in particularly the location – each install will come with its own unique set of challenges.
A small 2KW system could cost from around £6,000 up to £10,000 but going taking it up to a 5KW system and potentially generating more than twice the electricity may only mean going up to around £15,000. That’s because of the cost of installation which is likely to be high (depending on the location) but remain fairly constant regardless of the size of the hydropower system.
Do I need planning permission for a hydropower system?
The answer is yes – you will need to obtain planning permission before installing any domestic hydroelectric system – no matter what the size of the system.
Contact your local planning office for further information.
In addition all small hydro and micro hydro systems must have hydro licensing issued by the environmental regulator, which is the Environment Agency (EA) in England and Wales, Scottish Environmental Protection Agency (SEPA) in Scotland and the Northern Ireland Environment Agency (NIEA) in Northern Ireland.
You will also need permission from them to do ‘work in the river’ when the system is installed.
If you live in Scotland you will also require an abstraction licence from the Scottish Environment Protection Agency for which there is an application fee.
Overall the planning and licensing process can be lengthy and bureaucratic so be prepared!
Are grants available for a hydropower system?
No – there are no Government grants available to support the cost of installing a hydropower system. Should this change we will obviously let you know.