Hydropower - flexible clean energy

Hydropower is the most important form of renewable energy in the Nordic countries. Apart from being a renewable source of power, it produces no CO₂ emissions. Hydropower is also predictable and reliable, as well as flexible. That makes it possible for hydropower to be the regulator that fills the gaps when the wind is not blowing and the sun not shining, and the other renewables can’t produce. This makes hydropower crucial in the change towards a renewable future.


Hydropower helps fight climate change because it doesn’t produce harmful emissions.

Flexible hydro power

Changes in other production forms, or in demand, can be met by turning hydro power on or off.

Renewable energy

The reservoirs collects the water that is part of a never ending natural cycle, no other fuels required.

Hydro power plant producing hydro power in sunset

Key numbers for 2019

Hydropower totals for the year


megawatts (MW) of power capacity


terawatthours (TWh) of electricity produced

32,9 %

share of Fortum’s total power output

Reducing our footprint

A clean-energy future means generating electricity without producing CO2 emissions. For us, hydropower provides much needed electricity while also playing an important role in minimising our carbon footprint and helping mitigate climate change.

Hydropower enables more renewables

More production capacity is needed during times of peak power demand, or when wind and solar can’t produce. Hydropower and water flow management offers the needed flexibility to meet changes in production/demand without increasing CO2 output. This means that the more flexible hydropower you have the more other renewables you can build.

Efficient and reliable

The operating of hydropower is very reliable since the water needed to generate power can be stored in reservoirs. Not only does this provide the stability needed for the grid to function, but it also means that it helps keep the price of electricity more stable for our customers.

FAQ - Hydropower

What is hydroelectric power?

A CO2-free power generation method that uses the energy created by water flowing through a dammed waterway to create electricity.

How does hydroelectric power work?

Hydropower plants utilise the difference in height between the dammed water and the outflow area to generate water flow energy which rotates a turbine that drives an electric generator. The same water can then be utilised again in the next plant downstream.

Where can hydropower be found?

Fortum operates about 160 hydroelectric power stations in the Nordic region. 

Is hydropower safe?

Yes, our hydroelectric power plants are built to withstand a flood that statistically occurs every 700 to 5000 years and we invest millions of Euros in dam safety every year.

Hydropower and the environment

Nordic hydropower has no global environmental impact as it does not produce carbon dioxide emissions into the atmosphere. However, hydropower production has local environmental impacts due to the regulation of the flow and water levels and the damming of the river.


Environmental approach

Read about our environmental approach within hydropower

Get to know our power plants