Grid Level: The 7 Tiers of the Electricity Grid

The Netzebene (grid level) denotes one of the seven tiers into which the Swiss electricity grid is divided, from the extra-high voltage of the transmission grid (grid level 1) to low voltage at the end consumer (grid level 7). The odd levels 1, 3, 5 and 7 are voltage levels; the even levels 2, 4 and 6 are the transformation stages between them. The grid level matters for self-consumption models because a LEG may only use levels up to 36 kV, in practice levels 5 and 7.

In Switzerland, electricity flows from the transmission grid through several transformation stages to the end consumer. Grid level 1 is the transmission grid at extra-high voltage (380 and 220 kV), grid level 3 the high-voltage grid (36 to 150 kV), grid level 5 the medium-voltage grid (1 to 36 kV) and grid level 7 the low-voltage grid below 1 kV, to which buildings and commercial businesses are connected (classification according to Swissgrid). Grid levels 2, 4 and 6 are not lines but the transformers between the voltage levels.

Two levels matter for commerce and industry. Grid level 7 is the low-voltage level below 1 kV; on it, a vZEV may use the service line and the local infrastructure at the grid connection point (Art. 14 para. 3 EnV). Grid level 5 is medium voltage, where larger businesses with their own transformer station are connected.

The LEG turns the grid level into an admission criterion: all members are on the same grid level, and the community may only use levels up to 36 kV, without exchange across higher levels (Art. 17d para. 2 StromVG, Art. 19e para. 3 StromVV). According to the BFE, that means grid levels 5 and 7. The discount on the grid usage charge depends on it as well: 40 percent if the electricity flows from every system to every end consumer without voltage transformation, 20 percent if it has to pass through a transformation stage (Art. 19h para. 1 and 3 StromVV).

Which model fits which connection situation: ZEV, vZEV or LEG: which model fits your site.