1. Define what the contract records
Ask how each export and purchase is valued, with a sample bill. Clarify any cap, monetary conversion, charged losses or expiry date. A commercial balance is not proof that your own summer electricity is physically retained until winter.
2. Verify the offer for your address
Obtain the contracting company’s name and dated product terms. Confirm the service area, required meter, supply contract and DSO procedures. A foreign advertisement or a similar product name does not establish availability in Switzerland.
3. Compare all charges
Request a simulated annual bill separating purchases, credits, feed-in payments, subscriptions, network, metering, levies and VAT. Check price revisions and unused-balance treatment. Compare the total with your current contract; a higher feed-in tariff is insufficient if other charges rise.
Illustrative example: a larger credit can still cost more
Assume CHF 1 000 in purchases and CHF 200 in surplus revenue: the net cost is CHF 800. Another offer with CHF 900 in purchases, CHF 250 in credits and CHF 180 in fees gives CHF 830. It costs CHF 30 more despite the larger credit. These amounts illustrate the calculation only; they do not describe a supplier.
4. Distinguish billing from backup
Do not infer power during an outage from a bill credit. For a physical battery, confirm usable capacity, power, losses, warranty and backup equipment. Compare backup needs separately from the financial result; an installed battery alone does not guarantee that the home stays powered during an outage.
5. Plan how to leave the contract
Clarify duration, renewal, notice, exit fees and balance settlement. Ask what happens if you move, sell, change supplier or the product ends. Keep the terms and sample bill, then reassess the result after a complete year of measurements.