Keep the two numbers separate.
Your electricity statement shows energy use and an amount due. They answer different questions. Keep both available when you discuss your home. Our simple planning tool annualizes a monthly dollar amount; it does not model energy production.
Look beyond one month.
Collecting statements across a year can help you see how your own pattern changes. Note anything unusual in that period: extended travel, a new appliance, or a change in who lives at home.
Use the baseline to ask better questions.
Ask a proposal to distinguish your existing spending from system costs and any utility costs that remain. Request the assumptions in writing. A useful comparison should be understandable without a sales presentation.
Further reading: DOE: Will I Save Money with Solar Energy?. General education; project-specific answers depend on your home and agreement.
