From 2027, electricity labelling becomes quarterly. Here is what this changes for your solar guarantees of origin, their price and your sales contract.
What does 2027 change for solar guarantees of origin?
The correspondence between production and consumption becomes quarterly for the marking of electricity. A guarantee of origin, or GO, indicates the characteristics of registered production. It does not represent a second physical kWh. For a solar owner, the practical question is who holds that value and on what terms it is sold.
The FOEN guide on the marking of electricity, published by Pronovo, describes the rule applicable from the delivery year 2027. The guarantees allocated to electricity delivered during a quarter must come from this same quarter of production. The document also specifies that the information sent to the customer remains annual. A commercial contract can therefore maintain annual invoicing: do not confuse correspondence period and payment frequency.
Injected electricity and guarantee of origin: two values
Your installation can produce three distinct financial results: purchases avoided thanks to self-consumption, remuneration for the surplus injected and, if the conditions are met, remuneration for the guarantees associated with eligible production. The price displayed by a buyer may include or exclude this last component.
When faced with an offer at an amount per kWh, ask a simple question: “Does this price include the guarantee of origin?” Then request the two separate lines. This avoids comparing an energy offer alone with an offer including energy and original attribute. Also check the quantity concerned: total production, measured injection or admissible volume recognized in the system are not interchangeable expressions.
For guarantees linked to your self-consumption, the official guide provides for their cancellation: they cannot then be resold. Therefore, do not apply a GO sales price to all annual production without checking the portion actually available. This error easily inflates a simulation, even when the unit price seems modest.
How to compare two offers with a simple calculation
Let's assume, just to illustrate the method, that 6’000 eligible kWh are available for sale. Buyer A offers CHF 0.01 per kWh without a flat rate: the annual income is CHF 60. Buyer B offers CHF 0.015 per kWh, but charges CHF 45 for management: CHF 90 less CHF 45 gives CHF 45. The higher unit rate produces the lower net income here.
Add to the calculation any initial costs, spread over a reasonable period, and the duration of the commitment. Check if the price is fixed, variable or revisable per quarter. A bonus reserved for new customers should not become a permanent revenue in your financial plan. Ask what happens if actual production is less than estimated.
A bundled offer can remain interesting when it simplifies the procedures. Evaluate this simplicity explicitly: what income do you give up, what formalities do you avoid and what exit possibilities do you retain? For a small facility, the gain from a separate negotiation may be too small to justify the administrative costs.
Will winter guarantees necessarily be worth more?
The new correspondence makes the production season more important. However, it does not set a universal price for your roof. The price actually offered depends in particular on the buyer, the quality sought, the duration of the contract and the volumes available. A seasonal scarcity perspective is not a promise of income for each producer.
Ask for an estimate spread over the four quarters. A house that produces mainly in spring and summer cannot use all its kWh at the price of a winter quarter. Use the production simulation of your roof, with its orientation and shading. If the offer only includes an annual price, specify how seasonal variations are taken into account.
Don’t add a battery just on the assumption that it would turn a summer warranty into a winter warranty. Storage does not allow you to freely modify the production period entered in the supporting documents. Any arrangement combining storage and certificates must be validated within its precise framework. A domestic battery intended to shift consumption hours firstly involves another calculation.
What should you check before giving up your guarantees?
Find the documents for your installation: registration, measurement data, takeover agreement and possible standing transfer order. Ask the installer what has already been organized during commissioning. Remuneration that is barely visible on the invoice may be linked to an existing commitment.
- Identify the rights holder and the person authorized to sign.
- Check the volumes transferred and the existence of exclusivity.
- Clarify the price, fees and the possibility of changing the conditions.
- Note the duration, renewal, notice and procedure for revocation of the transfer.
- Ask who corrects the data when a measurement is corrected.
- Keep proof of volumes transferred and amounts received.
A contracted installation, a rented roof or a PPE requires particular attention to the ownership of rights. The building owner is not necessarily the one who can sell all the guarantees. The answer should come from signed contracts and the registration file, not from a guess based on the roof address.
How to prepare for the transition to 2027 without losing a useful contract
Start by asking your current buyer for their terms for 2027. Compare them with another offer on the same quarters, volumes and fees. Before canceling, make sure that a new buyer actually accepts your installation and that transfers can be organized without overlap.
Establish an end date for the old commitment and a start date for the new one. Confirm which volumes fall under each, especially when a statement arrives after the production period. A change of contract must neither grant the same guarantee twice nor suggest that a quantity already transferred is still available.
What does “Swiss solar electricity” mean for your consumption?
If you purchase a renewable electrical product, warranties document the origin attributed to that product. They don't physically trace each electron back to your socket. This distinction helps to read an offer without confusing certification, local supply and autonomy of the building.
For a company, specify the supporting documents that can be used in your communications and reporting. For a household, compare the additional price with the quality promised and the marking document received. In either case, avoid claiming that the same environmental attributes belong to multiple buyers simultaneously.
The decision to make for your roof
Treat the GOs as an identifiable line in the solar record. They can provide a revenue, but their amount must not mask production, self-consumption, installation price or remuneration for energy. Start with a conservative estimate of net income, then consider whether a more complex contract provides a significant improvement.
Before signing, you need to know the available volume, net price, rights holder and release conditions. If an offer presents guaranteed income without these four elements, ask for a detailed statement. To distinguish the effects of storage, also consult the guide on reimbursement of battery network costs.