Water is the source of almost all the energy produced in Norway. Water is also the source of all life. SINTEF is developing models which describe the hydrological processes which take place within the catchment areas and which thus determine water flow into the hydroelectric reservoirs. In drainage basins which are developed as hydroelectric projects we are able to model the effects that power generation has on the environment of the basins and how we can best avoid negative environmental impacts.

Precipitation is the most important input variable in hydrological models. Precipitation is measured by rain gauges at discrete points, but these values become significantly altered during the calibration of the model in order to correct for failures to collect precipitation, representatvity, etc. SINTEF is working to develop better and more objective methods of recording precipitation data, both in terms of how we deal with discrete point values and how we extrapolate these over larger areas.

Measuring snow depths using radar

Snow is important in many contexts. Snow coverage has a very major influence on local and global climates and also has a major bearing on biological conditions. The snow reservoir held in upland areas is the most important and in part the least well studied resource available to the energy sector. During periods of low precipitation and run-off, the emphasis on and interest in better data availability and utilisation become more important. SINTEF is working on the use and development of existing modelling tools in order to simulate the redistribution of snow and snow melting processes. The acquisition of snow-related data is an important task. 

Hydroelectric power plants
A hydroelectric power plant consists of one or more reservoirs, water conduits and a power station. The dams may be constructed using either concrete or rockfill. The water conduit down to the power station is normally in the form of a tunnel, parts of which may be lined with concrete. If high pressures are involved the lowermost part of the pressure shaft may be lined with steel pipe. 

The power stations are most often buried within the bedrock and contain one or more turbines and generators. Transformers and switching stations are also frequently located underground.

Power production is controlled by regulating the opening to the turbine, i.e. by regulating the water volume permitted to flow through the turbine. The turbine is connected to the generator via an axle. Mechanical energy from the turbine is converted into electricity in the generator via a magnetic force field which arises between the rotating component of the generator (rotor) and its stationary component (stator), which in turn is linked to the electricity distribution grid.

Norwegian hydroelectric power plants are for the most part entirely automated and unmanned under normal operational conditions, and may often be controlled remotely from a central operations centre.

Salt power plants
We can generate energy by exploiting the osmotic pressure difference across a membrane separating salt from fresh water. Fresh water is the limiting raw material which determines the output of the power plant. SINTEF is conducting research into membrane technology, water constructions and environmental impacts linked to salt power plants.

Tidal water
The combination of the Earth's rotation and the forces of attraction induced by the Sun and Moon on the Earth's water masses generates powerful tidal currents and major differences between high and low water at many locations around the world. Focus on the exploitation of this predictable energy source has increased immensely in recent years. It is either possible to exploit the elevation difference between high and low water (which should be greater than 5 metres), or energy generated by the velocity of the water current. This is achieved in much the same way as for a wind farm, and using very similar types of turbine. SINTEF has been closely involved in the design of a tidal turbine for Hammerfest Strøm AS which will be installed in Kvalsundet during 2003. This is a vertical-axled water turbine with a rotor diameter of 20 m, and is mounted on a tripod which is fixed to the seafloor with the aid of gravity.