With dramatic snow-capped mountains and breathtaking alpine lakes, Switzerland must be one of Europe’s most picturesque countries. Aside from the Instagram opportunities, the beautiful landscape also equips Switzerland with its number one renewable energy source, hydropower. The elevated slopes and steep valleys combined with water retention in glaciers and lakes provides an ideal environment for hydropower production.
Switzerland has a target of net-zero by 2050, the same target as the UK. Their extensive hydropower generation will be a great help to reaching this target. Hydropower is responsible for almost 60% of Switzerland’s electricity production. The small country (1/6 of the size of the UK) has 672 hydropower plants which have a combined annual production potential of 36,567 gigawatt hours. This is enough electricity to power over 8 million homes!
So, lets take a look at how hydropower works…
There are four main types of hydropower; run-of-river, storage, pumped storage and offshore hydropower.
A conventional hydroelectric plant is broken down into three parts:
- A reservoir storing water
- A dam that controls the water flow
- A power plant where the electricity is produced
As water flows through an intake, the kinetic energy is converted into mechanical energy by a hydraulic turbine. A generator then converts the mechanical energy to electricity.
What are the advantages of using hydropower?
- First things first – hydropower is a renewable electricity source. The energy source, flowing water, is clean and renewed by rain and snow.
- Hydropower is a flexible electricity source which can respond quickly to changes in energy demands. The storage capacity of reservoirs allows for electricity production any day, any time.
- Hydropower produces a low amount of greenhouse gases over its lifespan compared to other electricity sources. The median life-cycle carbon equivalent intensity of hydropower is 18.5 Gco2e/kWh compared with 820gco2e/kwh for coal.
- As well as producing electricity, hydropower dams can be used as a clean water source and for recreation.
- Hydropower projects can help to regulate water flow, reducing the impacts of droughts and flooding, which are unfortunately becoming more frequent as a result of climate change.
Now that all sounds great, lets look at the drawbacks of hydropower…
- Hydropower can have a negative impact on aquatic life. For example, dams can prevent fish from reaching their breeding ground, reducing fish populations and in term affecting species higher up the food chain.
- The initial cost of installing a hydropower plant is high.
- Risk of dam failure which can have catastrophic effects on surrounding communities and ecosystems.
- Decaying organic materials in reservoirs can release methane and carbon.
Mitigation of harmful environmental and ecological impacts is becoming a priority at many hydropower plants. As an example, fish passages are being implemented to ensure fish can continue to migrate.
Can we learn from the Swiss?
Whilst Switzerland seems like a prime case study to encourage the use of hydropower elsewhere in the world, this system can’t be applied everywhere. In some geographical areas, the topography simply isn’t suited to hydropower production. In addition to this, installing hydropower plants in a suitable location may require the displacement of large communities which may not be feasible or can be simply unethical.
This being said, we can definitely learn from the Swiss focus on renewable energy, and hydropower could form a more substantial part of our energy mix in the future. Hydropower can provide a perfect accompaniment to other renewables such as wind and solar. When these irregular sources aren’t available, hydropower can fulfil the demand, helping us to come closer to a 100% renewable energy future.