Start with the property and the electric bill
A useful solar proposal begins with twelve months of electricity use, roof condition, shade, rate plan, and the homeowner’s goals. System size should follow those facts rather than a generic savings promise.
Compare the same scope
Ask each installer to identify equipment models, estimated annual production, degradation assumptions, warranties, roof work, interconnection tasks, financing terms, and battery operating assumptions.
Verify before signing
Check the contractor licence, authorized signer, insurance, cancellation terms, payment schedule, production guarantee language, and responsibility for permits and utility approval.