A production forecast is only one part of the project. Define the works, local steps and intended use of the electricity together.
Get a property-specific forecast
Ask for a forecast that uses the actual orientation, shading and roof area. Compare summer and winter production with your consumption pattern. ADEME’s household electricity-generation guide offers an independent starting point for understanding the technology.
Put the local steps on one page
Ask who will check planning requirements with the mairie and manage connection with the relevant network operator. Identify what documents are needed before installation and commissioning. Write the responsibilities into the project schedule instead of assuming the installer handles everything.
Agree how surplus will be used
Decide whether the proposal includes selling surplus, storage or another arrangement, then obtain the relevant terms. Keep estimated generation separate from promised bill savings. Any support or export income included in a quote should have its eligibility and assumptions identified.
Prepare the information the project team needs
Collect roof photographs taken from the ground, electricity consumption, meter details and any existing drawings. Note ownership arrangements and planned roof or heating works. Present the same pack to each installer. Ask them to identify missing information during the survey, rather than quietly filling gaps with assumptions. Record the selected panel layout and equipment positions so later changes can be compared with a clear starting point.
Keep production, use and sales separate
Request a monthly forecast showing generation, expected direct use and surplus. Put the import and export prices beside the relevant quantities. For a simple example, 500 kWh used at home replaces €150 of purchases at €0.30/kWh; selling the same amount at €0.08/kWh earns €40. Those are example prices, but the distinction explains why a production forecast alone cannot determine the financial result.
Coordinate the mairie and network steps
Keep local planning questions, the network connection and any surplus-sale contract as separate items in the schedule. Ask who contacts each organisation, what they submit and what confirmation is needed for the next stage. If the property has special planning constraints or shared ownership, identify the issue early. Do not use the installation date as a substitute for confirming that each relevant step has been handled.
Your planning checklist
- A shared property and consumption brief for all installers.
- A panel layout and monthly energy-flow forecast.
- Named responsibility for mairie, network and sale arrangements.
- An itemised price and a complete handover schedule.
Common questions
Can the installer handle all the administration?
They may offer to handle parts of it. Ask for the exact tasks, required authorisations and copies of the resulting documents. Keep the remaining homeowner tasks visible in the same schedule.
Should I add storage to avoid any surplus?
Compare its extra cost and benefit separately. Exporting some electricity may be a reasonable part of the design; eliminating all surplus is not by itself a financial objective.