What do hydroelectric systems do?

Hydroelectric systems use moving water such as a stream or river to generate electricity.

Small, ‘micro’ hydro-electricity systems produce enough electricity for lighting and electrical appliances in an average home, or on a wider scale.

Hydro-electricity systems may also be referred to as hydro-power systems or just hydro systems.

How does a hydroelectric system work?

Hydropower systems utilise running water, they use flowing streams, brooks or rivers to turn small turbines, which then generate electricity. The faster the water flows, the more water there is and the greater the amount of electricity that can be generated.

The generation capacity of a hydroelectric system is dictated by the efficiency with which it converts the power of the flowing water into electrical energy.

What are the benefits of a hydroelectric system?

  • Reduced carbon footprint. Hydroelectricity is a renewable energy which does not produce or release any harmful carbon dioxide or other pollutants.
  • Reduced electricity bills. Once the initial installation is paid for the hydroelectricity produced is free. Depending on your level of demand against the supply, electricity bills can be reduced or even eliminated
  • Lower installation cost. National Grid connections can often cost more than installing a hydro system.
  • Less expensive heating and hot water. Hydro systems can generate more electricity than is needed for lighting and appliances in the property they serve. The surplus can be used to heat the property and/or water.

Is a hydroelectric system suitable?

Here are a few key questions to consider:

Can you access moving water?
Does a watercourse such as a river or steam run close to your home, preferably on your own property?  It is necessary to be able to access a fairly fast running watercourse and to have the right to build around it.

Is the flow consistent?
If the water flow varies significantly during the year the hydro system may not be able to supply all the electricity needed in any drier months.

If there is no back up mains electric connection then consider another form of generation, either as back-up or as the main source.

What happens if excess energy is generated? 
If a suitable connection point is available the hydro system can be connected to the National Grid. This will allow any excess electricity you generate to be sold to the main electricity companies.

Find out more about selling your excess energy on the Energy Saving Trust web site at http://www.energysavingtrust.org.uk/

Find out more about the feed in tariff at: http://www.energysavingtrust.org.uk/Generate-your-own-energy/Sell-your-own-energy/Feed-in-Tariff-scheme

What are the Costs and Savings?

The installation cost for a hydro system will vary depending on the location and the volume of electricity it can generate. A typical 5kW scheme suitable for an average sized home could cost £20,000 - £25,000 including installation.

These will depend on the amount of electricity previously, or alternatively, purchased from a main supplier, as opposed to what the hydroelectric system can generate.

Fuel costs
If a hydro system replaces electricity previously purchased from the National Grid savings could be significant.

At the time of writing hydro systems are eligible to receive generation and export payments through the Feed-In Tariff.

Costs will be variable. However they are usually low as hydro systems are very reliable.

Curious about the technologies?

For more information on home energy generation technologies, contact your local Energy Saving Trust Advice Centre on 0800 512 012.

For specific technology questions, visit the Heat Pump Association at http://www.feta.co.uk/hpa/