The quality of the offer depends as much on the site as on the price displayed. Check the site data and official sources before signing.
Decision to make
The quality of the offer depends as much on the site as on the price displayed. Adapt this decision to the building, your actual consumption and the project schedule.
For this project, start by identifying the grid operator, applicable tariff and site constraints. The quotation must specify the conditions affecting connection, metering or the value of surplus electricity.
Practical effects of the project
- Check the grid operator responsible for the project address: one region can have several operators and different arrangements for surplus remuneration.
- A local quotation must relate prices, grants, roof conditions, site access and grid connection to the actual building.
- Sonnendach serves as a pre-check, but urban shading, snow, access or heritage protection are validated on site.
- Check grants through Energiefranken, the municipality and the relevant organisations, then confirm their conditions; the federal information sheet does not cover every local programme.
- A serious local quote cites the municipal procedures and the expected connection time.
These points help assess the topic ‘ Solar panels in Solothurn: costs, support and installers ’ without turning a national average into a local promise. Every decisive figure needs its source, date and scope.
Specific controls
- Confirm site data with the relevant professionals and connection conditions with the grid operator.
- Show base price, options, connection, aid and exclusions separately.
- Compare a reference hypothesis with a conservative variant before signing.
The answers should appear in the quote or in a dated appendix. A verbal explanation is insufficient if it changes the price, expected output, financial support or a contractual obligation.
Compare quotes
- Tariffs: state the purchase price, surplus remuneration and fixed charges applicable to the site, with their source and date.
- Production: provide a monthly estimate with orientation, shading, losses and weather assumptions.
- Investment: separate material, installation, safety, scaffolding, connection, procedures and options.
- Aids: distinguish confirmed amount, estimate and deposit liability.
- Contract: specify guarantees, calendar, deposit, exclusions, maintenance and after-sales service.
The quality of the offer depends as much on the site as on the price displayed. In the comparison table, keep one column for the stated value, one for the evidence provided, and one for the effect of a less favorable hypothesis.
Cautious scenario
Test the project with slightly lower production, an unconfirmed grant and less favourable surplus remuneration. This scenario shows whether the decision remains sound based on self-consumption, roof quality and a controlled installed cost.
The main references used are ElCom - Slight drop in electricity prices in 2026, Energiefranken - Search for energy aid by municipality, Confederation - Sonnendach / solar potential of roofs, SFOE - support for photovoltaic installations. They frame the method, but the local amounts and contractual conditions must be rechecked at the time the offer is signed.
Risks to be managed
A serious local quote cites the municipal procedures and the expected connection time. Ask who assumes this risk, what proof will be provided and how a change is handled after ordering.
A more expensive solution should meet a specific need in your project. Ask for a documented benefit and a separate price for each option.
Next step
Gather the address, annual consumption, future electricity uses and building documents. Then check the grid operator's conditions, available grants and site constraints; request quotations covering the same scope.
The quality of the offer depends as much on the site as on the price displayed. You can then decide with a documented net price, clear responsibilities and assumptions that each company can explain line by line.
A Solothurn example: roof renovation before a change of use
Consider a building whose roof needs assessment and whose use may change from storage to a workshop. This case assumes neither your roof’s condition nor its materials. Have structure and suspect materials inspected before planning work; owners should not take hazardous samples themselves.
Request options for current and planned use. The new profile may change demand power, ventilation and consumption hours. Separate renovation from PV equipment in quotations.
Compare combined construction with later solar installation, including possible removal, warranties and closure of premises. Scaffolding savings do not justify installation on a roof with an undefined renovation plan.
Points to check
- Tariffs: Compare the tariff for your address with the Swiss ElCom median for 2026, keeping local prices separate from the national benchmark.
- Grants: Check the programme, eligibility, documents and deadlines with Pronovo, the canton or municipality. Include only confirmed contributions in your budget.
- Roof potential: Sonnendach is presented as a public pre-diagnosis, to be validated by a technical visit.
- ROI: the method separates self-consumption, injection, installed price, taxation and payment schedule.
- Check the grid operator responsible for the project address: one region can have several operators and different arrangements for surplus remuneration.
- A local quotation must relate prices, grants, roof conditions, site access and grid connection to the actual building.