How a solar project unfolds, from simulation to commissioning

A solar project feels long because it feels vague. Once you know who does what and in what order, it becomes above all a series of short stages, only one of which truly depends on you: the decision.

1. The simulation, online and free

Everything starts with your address. The simulation draws on public data from the federal register of buildings and on the solar irradiation measured at your coordinates to estimate your roof’s potential: usable area, expected production, potential savings, and applicable subsidies.

It is an estimate calculated on public data, not a national average. It answers the first real question: is this project worth studying seriously? If the answer is yes, an advisor then builds the detailed simulation with you, over the phone.

2. The technical visit, within two weeks

Once the detailed simulation is launched, an engineering office comes on site within two weeks. Its job: checking what public data does not show. The condition of the roof structure, the electrical panel, actual shading, access constraints.

This visit turns an estimate into a specification. It is what allows installers to price seriously, with no bad surprises once work is under way.

3. The call for tenders, two weeks

Your specified project then goes out to the installers in the network. The offers received are scored and compared, line by line, on equipment, warranties, and terms. You do not have to chase three quotes or decipher them on your own: the comparison arrives ready-made, and the same advisor remains reachable throughout the call for tenders.

4. The choice and the signature, immediate

When the compared offers are in front of you, the decision is yours. The day you choose, signing happens electronically, with no appointment and no paperwork.

In total, allow about one month between launching the project file after the detailed simulation and signing your offer.

5. The installation work, by your installer

The installation itself is carried out by the installer you chose, according to their schedule and the season: allow two to six months depending on the project. They are your contact for the worksite, equipment lead times, and commissioning.

What to remember

The part that depends on platforms and professionals is short and tightly paced: two weeks for the technical visit, two weeks for the call for tenders, an immediate signature. Start with the free simulation: it tells you in a few minutes whether your roof deserves the next step.

To prepare for the stages that follow, two useful reads: why comparing several offers changes everything, and how to read a solar quote for the day they arrive.