Ourpower Guides - Hydro - Details

Hydro electricity is produced from fast running streams or rivers. It is a mature technology, used for thousands of years. These days smaller water turbines are used, as opposed to the water wheels of the past.

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Hydro produces electricity.

Benefits

Hydro systems can be very effective for properties with the right water resources at their disposal. For an off-grid property (not connected to the electricity grid), the cost of installing the hydro system can often be cheaper than installing a grid connection.
The production of electricity can be more reliable and cost-effective than other renewable systems.
Typical uses are as follows:

• Producing electricity at remote homes, where a suitable water resource is available.
• Community or larger-scale schemes.

How does Hydro work?

A Hydro system converts energy in flowing water to electrical energy. Three factors affect the power produced:

• The flow rate of the river (in litres/second) and how much of that can be diverted into the system. The greater the flow that can be used by the system, the greater the power.
• The height that the water drops, known as the 'head'. The systems are setup to provide a fall of the water before it enters the turbine to maximise the power available. Typically, systems are defined as being low, medium or high head depending on the planned/potential head, with 'high' providing most power.
• The efficiency of the system in converting the water energy to electricity. Efficiencies up to 90% are possible, but 50-70% are more likely for smaller systems.

It should also be noted that, much like wind power, but to a lesser extent, the production of power does fluctuate, both seasonally throughout the year, and also day to day depending on rainfall. However, correctly sited hydro is generally considered a reliable, steady power source.
Water turbines are available rated at between 200 watts and 50 kilowatts.

Is it suitable for my home?

Factors that need to be considered are typically:

• Is there a suitable stream or river, close to the property where the electricity can be utilized, or sold back to the grid (if connected).
• To determine the potential of the site, an initial evaluation may need to be paid for from a qualified installer. This may cost between £300 and £1000.
• The environmental impact on the stream or river and the downstream affects must be considered. The Environment Agency should be consulted and involved at an early stage.
• Planning Permission will likely be needed for the construction. The local planning authority should be consulted.

An accredited installer or supplier will help you plan the best system for your circumstances and budget as well as assisting with environmental impact and planning.

Connecting to the grid

Selling excess power produced is becoming easier, with plenty of advances expected in the future.
Households can connect to the grid through their fuse box (and if an export meter is bought for about £120) any excess electricity, being produced at any time, can be sold to your electricity provider.
The price paid is still typically less than you might pay for electricity, but opportunities are improving all the time as more and more people sell their power.
Additionally, Renewable Obligation Certificates (ROCs) are available for every megawatt hour of electricity produced per year. Increasingly there are options for electricity companies to deal with the complexity of ROCs and offer a combined electricity and ROCs package to householders.
 

Installation, maintenance and costs

Hydro costs are very dependent on the site and water resource available.
As a guide, costs may be in the region of £4,000 per kilowatt installed, although this will vary significantly, and drop for larger systems.
Grants are available from the Low Carbon Buildings Programme. Currently up to £1,000 per kilowatt (or to £2,500/30% of total cost maximum) is available for hydro installations.
The installation should be checked every year. Regular cleaning of debris may likely be required for river-installed systems. A generator may last 10-15 years, but the turbine should have a lifespan of at least 25 years.

Where can I find out more?

The DTI funded low carbon buildings programme provides grants to help with the costs of installing wind turbine.
To be eligible for a grant you will need to use a certified installer and products.
Or visit the following sites:

Visit: Energy Saving Trust

Visit: Centre for Alternative Energy

Visit: The British Hydropower Association

Look for Ourpower Pioneers in the Ourpower Community who have fitted Hydo Turbine systems near you so you can ask and read about their experiences. Then use the Ourpower Directory to find local installers and suppliers - reading about what they can offer and what they have done, before asking a number to consider your situation and to quote. Always, get at least 2 quotes - more if possible.

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