Electricity makes its way through a dense network of ultra-high, high, medium and low-voltage lines before it reaches the user. These systems are adapted to each other to ensure that transmission losses are kept to a minimum.

Electricity is usually generated in power plants at 21 kilovolts. It is then converted to the highest voltage (generally 380 kilovolts) in a transformer station located right in the power station.

As it makes its way to the consumer, high-tension lines see to it that large distances are covered with the fewest possible losses. Transformer stations await the electricity at conurbations and industrial sites, ready to step it down to 110 kilovolts of ultra high-voltage power.

Once it arrives at usage hubs, the electricity is then stepped down to 10 to 20 kilovolts so that it can travel through medium-voltage lines. Homes and commercial operations are supplied directly via the 230/240 volt low-tension grid.