THE SHORT ANSWER
Usually, the useful question is how much of the bill remains. Solar production, household consumption, fixed charges, and your utility’s treatment of exported energy all affect the result.
Solar offsets some grid purchases
Your system can supply energy your home would otherwise buy. The amount depends on production, your usage timing, and how the system is configured.
A bill can still remain
Customer charges, remaining electricity use, and other applicable charges can continue. Review the actual tariff that applies to your account.
Export credits need a specific review
Compensation for energy sent to the grid depends on your utility, tariff, and interconnection terms. Ask how credits are applied and reconciled for your account.
Keep the assumptions visible
Compare a full year where possible. Seasonal production, changes in consumption, and rate changes can all affect the result. A projected bill is an estimate.
Turn the conversation into a plan
Compare a full year of bills when possible, using both dollars and kilowatt-hours. A low bill in a mild month does not tell you what to expect during a hotter month with higher air-conditioning use. Separate the solar payment from utility charges in your household budget. Ask the proposal team to identify where the remaining-bill estimate came from and which tariff was used. If a presentation shows a zero utility bill, ask where customer charges and any other continuing charges are accounted for.
DOE identifies production, consumption, utility compensation, and financing as factors in the financial outcome. Historical incentive examples are not current eligibility advice. Further reading: U.S. Department of Energy: solar savings factors.
Questions for your project
- Identify your utility and current rate schedule.
- Separate fixed charges from usage charges.
- Ask how exported energy credits are calculated.
- Compare solar payment plus remaining utility costs.
Make it specific to your home.
Use your actual utility and twelve months of usage when reviewing the proposal.