Hydropower for the home

Small-scale hydroelectricity, or hydropower, can be used on a domestic scale to heat your home or run your appliances. Find out how hydropower works, how much it costs and how it can benefit you.

How does domestic hydropower work?

Hydroelectricity is based on the power of gravity. Water in rivers and streams flows downwards towards the sea; as the water passes through a hydropower system, the energy in the water drives a turbine which turns a generator and energy is produced.

The power of the system will depend on the strength of the water passing through, as well as the efficiency of the system.

There are three standard types of hydropower systems. The first is a standard ‘run of river’ system, which uses the existing flow of the river. Water is typically redirected to pass through the turbine and the water is passed back into the river or stream.

While this system is the most straightforward, it also has the disadvantage of being entirely dependent on the strength of the river. If your river goes dry due to drought, your system will not run.

However, due to its simplicity, it is also the most typical to use for domestic or community systems.

The second type is a storage system, or dam, which is the most common form. Dams are used for large-scale hydroelectricity projects around the world, but can also be used for smaller systems.

A reservoir stores the water from the river and lets it through gradually. This offers a greater degree of control because the system can still work if the river runs dry.

The final type is a pumped system, which uses cheaper, off-peak energy to pump stored water back up to a higher point to generate energy at peak times.

Is domestic hydropower practical?

Hydropower’s practicality depends entirely on your access to running water. But, even if you have a river or stream nearby, it doesn’t mean you can automatically consider hydropower. The Energy Saving Trust recommends hydropower as a worthy community development project rather than a power system for just one home.

If you think you may be eligible, you should contact a certified hydropower installer who can take a look at your site. Whether it is suitable will depend not only on your location and access, but also on how steeply the river flows and how much water passes through.

You should also consider the seasons. Your river’s lowest level will determine how feasible your site is more than your river’s highest level. This in turn will vary year by year depending on rainfall levels.

How much does it cost?

The cost of a hydroelectricity system depends almost entirely on its size and where you put it, but it's likely to be significant either way - the good news is that once the system is installed it requires very little upkeep.

The amount of energy the system will generate, and hence what your savings will be, is even harder to estimate as it will depend not only on the system but also on how long it can operate at full efficiency, which in turn depends on the water levels in your area.

What are the advantages and disadvantages of hydroelectricity?