Facts about hydro power

Hydro power harnesses the energy present in the movement of water, and is by far the leading renewable energy source in the EU.

According to Eurostat, hydro power accounted for approximately 12 per cent of the EU's electricity generation and about 40 per cent of total renewable electricity generation in 2014.

Hydro power in Europe

The construction of a large-scale hydro power plant requires the right kind of watercourse. The proportion of hydro power in the energy mix of countries such as Sweden, France and Austria, which have large differences in altitude and suitable watercourses, is therefore very high. Hydro power comprises over 99 per cent of total electricity generation in Norway, Europe's largest hydro power producer. Countries such as Denmark, Germany and Poland, on the other hand, do not possess the conditions suitable for hydro power.

Conflict between global and local considerations

Hydro power has very little impact on the climate and environment in the wider perspective. But large-scale hydro power does have a major impact on the environment in direct proximity to the plant and watercourse. This leads to distinct conflicts of interest.

Growing concerns about global warming have boosted the general public's perception of hydro power and it is now viewed as part of the solution to the climate change problem. The issue is not whether hydro power is positive or negative, but rather how many unspoiled watercourses should be preserved and how to increase biodiversity in developed rivers.

The natural water cycle

Solar heat evaporates water.
Water vapour rises, condenses and forms clouds.
Precipitation from clouds.
Solar heat evaporates water and so on.

Enlarged illustration

Energy triangle

In supplying society with energy, a balance must be struck between three key dimensions: competitiveness, security of supply, and the environment and climate. No single energy source is optimal from all dimensions. This energy triangle illustrates the pros and cons of hydro power.

Climate and environment: Hydro power is a renewable energy source that causes almost no emissions that impact the climate or the environment. However, power plants are a significant encroachment on the landscape and impact river ecosystems. A power plant may also affect animal and plant life in the vicinity.

Security of supply: Hydro power plants provide large-scale and stable electricity generation. But sustained high generation levels are dependent on precipitation. Hydro power also functions as balancing power, since capacity can be rapidly changed to compensate for differences in generation and consumption in the mains supply.

Competitiveness: Hydro power has no fuel costs and competitive generation costs. Constructing a new power plant requires a substantial investment, but its economic life is long.