What is Hydroelectric Energy?

And how does it work?



Hydroelectric energy is electricity generated through the use of hydro power i.e., using water. This may sound odd - and a little dangerous?! - but it’s actually a clean and renewable energy source that generates around a sixth of the world’s electricity.

How Does Hydroelectric Energy Work?

Footage with kind permission from United Utilities as part of the Pedal 4 Parks climate expedition.

Hydroelectric energy is generated when the kinetic energy of moving water, is converted into electrical energy. This is often achieved by the use of some pretty impressive infrastructure that contains and controls the flow of water and then uses it to generate emission free electricity.

The process begins by building a dam (or identifying a suitable existing one), across a natural river course so that the flowing water can be held back to form a reservoir. The flow of this water can then be controlled via grates on the dam that either let the water through when opened or hold it up in the reservoir when closed.

When the water is allowed to pass through the dam, it is directed through pipes to a turbine that has blades which are moved by the kinetic energy of the flowing water. The kinetic energy from the water becomes rotational (or mechanical) energy on the turbine, which itself is connected to an electricity generator. The generator converts the rotational energy into electricity which is either stored or sent to the national grid via power lines.

Is hydroelectric power renewable?

Well, the water isn’t used up in this process and is let out of the dam via a spillway or drain to continue flowing downstream it can be used time and again.

What Are the Advantages of Hydro Energy?

Reusable: The water used in this process isn’t depleted and doesn’t have to go through any other processes to be used. It’s ordinary rainwater that continues through the normal water cycle once it has passed through the turbine.

Sustainable: By helping reduce the demands on other sources of energy, hydro power reduces the output of greenhouses gasses into the atmosphere, as it doesn’t produce any itself.

Reservoirs Provide Flexibility and Support: By having reservoirs, many hydroelectric power plants can provide energy when other intermittent sources, such as solar power, can’t. This also offers flexibility of when that power is generated, as it can be used to help alleviate pressure on infrastructure during peak usage periods.

Water Control: Dams and reservoirs can be used to control water flow in areas that are prone to flooding, so that the risk is significantly decreased.

What Are the Disadvantages of Hydro Energy?

Reservoirs Need Very Specific Placement: There are only a limited number of places that are suitable for hydroelectric powerplants because reservoirs need very specific placement to avoid causing too much disruption.

Space vs viability: They can take up a vast amount of land and, even if an area is suitable, it doesn’t necessarily mean it will generate enough energy to be viable.

Environmental disruption: Like any other sort of energy infrastructure, hydro power can influence its surrounding environment. By placing dams on rivers, it can affect fish migration and the sheer scale of the infrastructure can negatively impact delicate ecosystems.

Water Isn’t Always Abundant: Like any other natural resource, water goes through cycles of abundance and drought, and whilst reservoirs make hydroelectric power more reliable than other natural resources, there may still be periods when it is limited. You can read more about how precious our water is in our blog here

How We Work to Minimise These Disadvantages

At 100Green, we always try to make sure our energy is as environmentally friendly as possible, and whilst any sort of infrastructure is going to have some impact on its surroundings – yes even the generation of green energy needs careful consideration! But the impact can be mitigated in certain ways. For example, we take a pragmatic view and have worked with generators who have made use of existing dam infrastructure that was built many years ago but is now being used positively to create renewable energy. We even work with a community project that supplies its local village with power and sells any excess onto us.

Our EKO Tariff takes this one step further, being not only 100% renewable but fulfilling strict sustainability criteria. This means that any hydro power used on this tariff comes from a source that safeguards a continuous flow of water, considers fish migration, and leaves suitable habitats for aquatic species. EKO energy is reliably tracked back to its source to make sure it always maintains these high standards.

We champion the production of green energy in UK and some of our energy has come from small hydro-electric schemes in places like Scotland and Derbyshire meaning that the infrastructure needed to support them is less intrusive than bigger operations – and more local, thus supporting the UK economy and the road to energy independence

How Many Hydroelectric Power Plants do 100Green Own?

100Green doesn’t actually own any generation plants. It may sound a little strange given that we’re an energy supplier, but instead, we focus our time on sourcing the greenest energy and look to buy, where possible, from smaller, sustainable producers here in the UK - and then sell it onto you, the customer. And, of course, we can concentrate on providing you with great customer service too!

How 100Green Uses Hydroelectric Energy

All of our energy is generated in sustainable ways, with no carbon offsetting needed because there’s no carbon produced. This includes our hydro power that is generated by small, sustainable producers and is sold onto us. We then use this energy to provide you with sustainably sourced electricity so you can power your home or business in a more environmentally conscious manner.

If you are interested in selling us green energy, we are always keen to hear from UK based generators – whether you have a domestic scale installation (less than 30kW) or are a commercial generator , we’d love to hear from you.

All of our Tariffs start with our Sparkling energy, and it is the only 100% green energy tariff in the UK. To find out how Sparkling energy is generated visit our Sparkling page here

If you want to take the meaning of green a little bit further, then check out our EKO tariff which is generated in locations that protect local wildlife (like migrating fish!)

Find out more about all our unique Tariffs and our 100% green energy by visiting Our Energy page