The short answer

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.

A practical next step

Before comparing prices, obtain a roof survey, generation forecast, full scope of work and written list of local administrative tasks.

Sources & further reading

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