The rooftop array, fully costed.

Two neighbouring municipalities can differ by ten centimes per kilowatt hour. On a typical system exporting 4,000 kWh that is 400 francs a year — over twenty years, more than the price of a battery.

Since the revision of the Energy Act a minimum price applies, based on avoided costs. It does not remove the spread, it only limits it from below.

In practice: where remuneration is high, a large array pays. Where it is low, almost only self-consumption counts — which moves storage and load shifting to the front of the queue.

The one-off payment typically covers a meaningful share of the investment and is paid after commissioning. Unlike the German scheme it creates no recurring income — after that, the economics rest entirely on self-consumption and the local export tariff.

Systems with little or no self-consumption can apply for the high one-off payment, which compensates for the reduced benefit.

Many cantons and municipalities add contributions of their own.

For apartment buildings this is the central lever: instead of releasing surplus at the low export tariff, the owner sells it to the tenants at a price that must sit below the grid tariff but may sit well above the export rate.

The grouping needs an internal metering concept and an agreement with the tenants; towards the grid operator it appears as a single customer.