Hydropower

Hydropower accounted for about 4% or Finland’s total energy consumption in 2008. Hydropower’s share of electricity production in Finland has varied in recent years within the range 10-15%, depending on precipitation levels and other hydrological conditions. Hydropower is Finland’s second most widely exploited renewable energy source, after bioenergy. In 2007 hydropower provided 14% of the renewable energy produced in Finland.

207 hydropower plants are currently operating in Finland (2006), including:

• 67 micro-hydropower plants (generating less than 1 MW)
• 83 small-scale hydropower plants (1-10 MW)
• 57 large-scale hydropower plants (generating more than 10 MW).

These plants have a total capacity of approximately 3,000 MW. Their total annual production has varied between 9.5 and 16.8 TWh over the period 2000-2008, according to water conditions. Finland’s hydropower plants produced 16.8 TWh of electricity during 2008.

It could still be possible to increase Finland’s hydropower capacity, though the main potential sources are generally well exploited. The total unexploited hydropower potential along river systems that are not protected for landscape or nature conservation is estimated at more than 600 MW, corresponding to annual production of over two terawatt-hours. Almost 400 MW (0.4 TWh/year energy potential) of this unexploited capacity lies on river systems that have already been harnessed to some extent. It is unlikely that hydropower developments could be launched along any remaining totally unharnessed rivers, for conservation reasons.

The most cost effective way to increase Finland’s hydropower capacity is to increase the efficiency of existing plants through technical improvements. Most of the unexploited potential available in already harnessed river systems (315 MW) could be realised through such improvements to existing power plants. Environmental protection factors make it unlikely that any major new hydropower developments will be permitted in Finland in the foreseeable future.

Hydropower plants are highly cost effective investments due to their long useful life. The capital investments made in older hydropower plants have already been amortised, leaving only running and maintenance costs.

Environmental impacts

The environmental impacts of hydropower plants are largely local in scale. Dams inevitably alter the hydrological conditions along the harnessed water course, due to the regulation of water levels. The flora and fauna of any land areas submerged under new reservoirs will be lost or forced to relocate. The same is true for any people whose homes are located in such areas, who may need to be re-housed. There is also a risk that any harmful substances such as heavy metals present in soils submerged under reservoirs will leach into the water and accumulate in fish and other creatures.

Carbon dioxide and methane may also be emitted into the atmosphere from submerged areas, especially if trees are not removed. Such emissions are a greater problem in tropical regions than cooler, temperate zones, however. Hydropower production does not itself generate any greenhouse gases, so increases in hydropower capacity are favourable in terms of mitigating climate change if they enable reductions in the use of fossil fuels.