In Norway we have divided the grid into three different levels: the nationwide main grid (power supply "highways"), which transports electricity from one area of the country to another; regional grids (power supply "county roads"), which transport power from the main grid up to the local area's distribution grids; and the local distribution grids ("local roads"), which distribute the power over the last stretch to the consumers. The power lines in the main grid have the highest voltages for the longest transport distances, over 200 000 volts as a rule. The regional grid power lines are usually between 66,000 and 135,000 volts, while the power lines in the local distribution grids are often up to 22 000 volts.

 

A household in Tønsberg may have power transported to the county via the main grid, then to Tønsberg via Vestfold Kraft Nett's regional grid and finally to the wall of the house via Tønsberg Energi's local distribution grid.

 

Main grid commercial agreement
Statnett owns more than 80 per cent of the power lines, transformers and switchgears in the main grid. The rest is owned by 27 other companies.

 

All of the "transmission facilities" in the main grid are part of a joint settlement scheme managed by Statnett. Statnett and the others who own such main grid installations, lease their power lines and stations in accordance with the main grid commercial agreement. Everyone who inputs or consumes power in the main grid pays a transport price in accordance with the commercial agreement. This is a national transport system that gives a common price system (tariff) for use of the primary transport grid.

 

The main grid commercial agreement shall give a break-even result over time. If the traffic revenues are greater than the leasing costs, then this is repaid in the form of lower transport prices in subsequent years. If the agreement gives a negative result, then this will be recouped through higher prices. At the end of 1999 the main grid commercial agreement gave an overall negative result of NOK 291 million.