How a LEG works, animated

01A LEG

A village that shares its power

This is what a local electricity community looks like at work: at midday solar power flows from the farm to the neighbours (green), and the rest comes from the grid as usual (blue). Scroll, and we take it apart piece by piece.

02Part 1 · Members

Who belongs

A farm, a chalet, renters in an apartment block, the village bakery and the municipal hall. Owners, renters, small businesses and the municipality itself can all join, each building with its own meter.

Renters don’t need a roof

03Part 2 · Producers

Solar on two roofs

The barn carries 48 kW of solar, the chalet 8 kW. The curve below the village shows their output across the day: a hill at midday, nothing at night. Whoever produces supplies the community; everyone else draws from it.

04Part 3 · Metering

A smart meter in every building

Every member has a smart meter. Every 15 minutes it measures how much power the building draws or feeds in. Those quarter-hour values decide who gets how much solar power from the neighbours.

96 readings per meter per day

05Part 4 · Grid

No new cables

Let’s lift the buildings. Underneath lies the grid operator’s existing local grid, with cable cabinets and house connections. A LEG uses exactly this grid: all members are in the same municipality and with the same grid operator.

Same grid, same municipality

06Part 5 · Transformer

The transformer is the gate

The dashed line surrounds the community’s local grid. Power that stays inside only uses this grid level, so the grid-use fee on the local share drops by 40% (20% when the transformer level is used; StromVV Art. 19h). Everything the village needs on top, or has left over, passes through the transformer.

−40% grid fee on the local share

07Morning

Before sunrise, it all comes from the grid

Early morning: the cows are milked, the bakery is baking, the sun isn’t up. Every kilowatt now comes from the grid (blue), exactly as today. With the first sunlight the farm and the chalet use their own solar power first.

08Midday

The surplus goes to the neighbours

Now the farm produces more than it needs. Every quarter-hour the surplus goes to the members drawing power at that moment, in proportion to their demand (green). Whatever is still left is fed in through the transformer and paid for.

Settled per quarter-hour

09Evening

When the sun is gone, the grid delivers

The sun sets and the flats start cooking. In the curve the blue area grows: whatever the village can’t cover itself comes from the grid operator as usual. Nobody is left without power; a LEG only changes where part of it comes from.

10Your day

Now it’s your turn

Drag across the model or use the arrow keys and play through the day yourself: quarter-hour by quarter-hour, how much comes from the village and how much from the grid.