Generate electricity using water

Domestic properties alongside a river or stream can generate their own electricity through hydropower. It’s clean, green and reliable.

Updated 16 June 2020  | 3 min read

Hydropower is most often seen on an industrial scale, but it works for some domestic properties too. Hydropower systems can be expensive to purchase and install, but they have the advantage of generating energy reliably and with little maintenance. To be suited to generating hydropower, a site must be on a gradient - the steeper the better - and have a source of water capable of turning a turbine.

Key points

  • Hydropower requires a site on a gradient with a stream or river
  • Run-of-river hydropower generation is cheaper but less reliable
  • Storage hydropower holds water and releases it for reliable generation
  • Hydropower systems are expensive but low-maintenance
  • The Smart Export Guarantee (SEG) means you can sell surplus electricity back to the grid

What is hydroelectric power?

Hydroelectric power is a renewable form of energy generated by water flow. Hydropower systems use rivers or streams to drive turbines, generating electricity. It’s a clean, green form of power.

Steep slopes make water run faster, which means hilly sites generate more power. The greater the water flow, the more electricity is produced.

Types of hydroelectric power

There are two kinds of hydroelectric power: run-of-river hydropower and storage hydropower.

Run-of-river hydropower

Run-of-river hydropower works by diverting water into a purpose-built canal, where it spins a turbine before re-entering the stream or river. This is the easiest type of system to install, but the power can’t be stored. If the stream runs dry, no power will be generated.

Storage hydropower

Storage hydropower works on a larger scale, with a dam to store water in a reservoir. The water is released gradually, turning a turbine as it flows. Storing water means electricity can be generated even when the river is not flowing at its usual level. Most projects are large-scale, but domestic storage hydropower systems are feasible too.

Advantages of hydroelectric power

  • One of the most reliable forms of energy, on the right site
  • Clean and renewable
  • Little maintenance required
  • Exporting energy to the National Grid can generate income

Disadvantages of hydroelectric power

  • Sites must meet specific criteria
  • Installation costs higher than other forms of renewable energy
  • Seasonal differences in water flow or drought impact energy generated
  • Fish and natural habitats can be impacted

How much does hydroelectric power cost?

Although it's possible to have a hydroelectric system installed for a single home, it's not cheap. Prices are likely to be in the tens of thousands of pounds. You'll also need your own water source, such as a river or reservoir.

The cost of a hydropower system varies according to the gradient of the land, the size of the turbine and whether you connect to the grid. You’d need to pay for a site survey to give you an accurate personal estimate.

Feed in tariffs and the Smart Export Guarantee (SEG)

Feed-in tariffs used to generate income for owners of hydropower systems, providing payment in exchange for power being put into the grid. This system was replaced by the Smart Export Guarantee in January 2020.

The SEG provides payments for power generated by hydroelectric systems with a capacity of up to 5MW. The amount payable is set by the licensed electricity supplier buying the energy. By law, the tariff must be above zero.