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How does hydroelectric power work?

Posted on 28 April 2017

At Co-operative Energy, we think it’s important to look after the world we live in. This is why we’re passionate about helping to reduce climate change, and giving our customers the opportunity to reduce their carbon footprint.

One way to combat the issue of climate change is by using renewable sources of energy to generate electricity – a method we’re now offering to our customers. We’ve launched our Green Pioneer tariff – a totally green product you can switch to, providing 100% renewable electricity and paperless billing.

Alongside this tariff, we also think it’s important that our customers understand where their energy comes from, and the options out there that can be used to create a sustainable world. We’ve been highlighting these in our ‘how does renewable energy work’ series, explaining the mechanics behind wind turbines and solar panels, plus more.

In 2016, the three community hydro sites we support through Power Purchase Agreements produced a huge 232 MWh of energy, enough to power 60 homes for a year and offsetting 210 t of CO2 being released. Read on to find out why hydroelectric power is such an innovative source of renewable energy.

What is hydroelectric power?

To summarise, hydroelectric power, namely hydropower, converts energy generated from fast-moving water (hydropower) into electricity.

What is a hydropower plant?

Hydropower plants create hydropower on a large scale, usually with the help of a reservoir. There are several types of hydropower plants, all of which use the principle of hydropower slightly differently to generate energy. These are:

Run-of-river hydropower: A simpler concept, this form of hydropower facility conduits flowing water through a penstock to spin a turbine, providing a continuous supply of electricity. It does not store water.

Storage hydropower: The most recognisable, this type of hydropower uses stored water in a reservoir. The water is then released from the reservoir, flowing through the penstock to spin a turbine, which moves a generator. Controlling the water is key, as it can be fired up when demand is high, and shut off at times of low demand.

Pumped storage hydropower: To meet demand during peak supply, pumped storage hydropower is similar to storage hydropower, but reuses the same water to provide electricity. The water is channelled through the penstock turbine, then pumped back up to the storage pool when demand is low, and channelled back down when demand is high.

Key components of a hydroelectric power station

A number of components make up a storage hydropower plant, such as:

  • Reservoir
  • Penstock
  • Turbine
  • Generator
  • Power lines
  • Transformer

How does hydroelectric power work?

hydro power

How much energy does an average hydropower plant generate?

A 200MW hydropower plant could supply 200,000 homes, based on the average electricity needs of a UK household, according to data from Renewables First. The amount of electricity generated depends on two factors – how far the water falls and the amount of water flowing through it.

Why choose hydropower over another form of renewable energy?

There are many benefits to a hydroelectric power station, in comparison to other green alternatives.

Cheaper electricity: In certain conditions hydropower can be the most cost-effective form of energy.

Responsive: Hydropower can be shut off or fired up during times of high or low demand, making it a highly responsive and flexible form of energy.

Flood control: Alongside its renewable benefits, hydropower can improve water supply and flood control.

Disadvantages of hydropower:

Disruptive to environment: In order to build a hydropower plant, ecosystems and habitats may be removed, affecting wildlife.

Expensive to build: The size of a hydropower plant and the construction of a project on this scale means it can be one of the most expensive to build.

Relies on water: For electricity to be generated, moving water is necessary, which during periods of drought can be minimal or even non-existent.

At Co-operative Energy, we believe that renewable energy sources are important, alongside reducing our customers’ energy usage. Providing energy-saving tips means our customers can also reduce their impact on the world, and on their finances. Find out how you could save money on your energy bills by reducing your usage, and help us create a sustainable way of living. 

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