Hydropower
Man has harnessed the energy in wind for thousands of
years, both for sailing boats and powering wind mills
at land. Of all renewable energy sources, wind power is
the most mature in terms of commercial development.
The development costs have decreased dramatically in
recent years, however most projects are still dependent
on public subsidies in order to be profitable. This energy
source is interesting because of its renewability and
its availability. Potential for development is huge, and
the world’s capacity is far larger than the world’s total
energy consumption.
Hydropower
The mechanical use of falling water is an age old technology. It was used by the Greeks to turn water wheels for grinding wheat into flour more than 2 000 years ago. It was not until 1870 that hydropower was exploited for the production of electricity.
How does it work?
The natural water cycle is driven directly by solar energy. When the sun heats up water in the sea and surface water, vaporization takes place and the water rises in the form of water vapor. The water vapor rises. When the water vapor reaches higher layers of air and is cooled down, the water falls down in the form of rain, hail or snow. The water runs naturally towards the lowest level and is transported on the earth surface in streams and rivers, and finally reaches the sea where it again evaporates. By letting the water flow through turbines on its way to the sea, we can harness the kinetic energy of the moving water to produce electricity.
Resource basis
On a global scale, is has been calculated that the total hydropower potential that is technically feasible to exploit is approximately 14 000 TW/year. Of this, 8 000 TWh/year is considered economically exploitable. [IHA/IEA, 2006].
Application areas
Hydropower has several advantages compared to many other sources of electrical energy. Hydropower is a renewable energy source that only to a small degree contributes to air pollution, acid precipitation or greenhouse gas emissions. Hydropower contributes to reduced use of fossil energy sources such as oil, gas or coal.
Technologies for storage reservoirs, dams and waterways
In Norway more than 330 large dams have been built at heights of over 15 metres. Norwegian companies have considerable experience and competence in construction, government regulations, reassessment and maintenance of dams.
Environmental impact of hydropower
Hydropower is an energy source that makes it possible to produce electricity without using fossil fuels, and is subsequently not part of the emissions caused by electricity production in coal, oil, or gas fired power plants. The environmental consequences of hydropower are related to encroachments upon nature due to damming or lowering of the water level, changed water flow and building of roads and power lines.
Technology development
The first hydropower plants were built in the end of the 19th century, while the large construction era started early in the 20th century. Many of these plants are still fully operational, although most of them are upgraded. Even though hydropower is a mature and reliable technology, it is still subject to development.
Norwegian hydropower actors
The Norwegian hydropower industry has a long tradition and is still one of the world’s largest producers of hydropower. Norway has developed competence that covers all aspects of a hydropower project; from planning and projecting to delivery and installation of hydropower technical equipment. In addition, authorities have developed expertise in regulating and administering hydropower resources through a hundred years of experience.
References
References to the information about hydropower.