Net metering
Under a traditional retail net-metering structure, eligible exported solar energy can offset imported electricity at or near the applicable retail energy value, subject to the utility's program rules. Billing periods, annual true-ups, non-bypassable charges and credit expiration can still matter.
Net billing
Net billing values imported and exported electricity separately. A homeowner may buy grid electricity at the retail tariff while exported solar receives a different compensation rate. If the export rate is materially lower than the retail rate, self-consuming solar can be more valuable than exporting it.
Time-of-use rates change the answer again
With time-of-use pricing, one kWh does not have a single value throughout the day. Midday solar exports may be credited differently from evening grid imports. Battery economics can therefore depend on both the export tariff and the hours when electricity is expensive.
Five utility details to verify before signing
- How exported kWh are credited and whether the rate changes by hour or season.
- Whether credits roll forward monthly and what happens at an annual true-up.
- Which fixed, minimum or non-bypassable charges remain after solar.
- Whether the program has system-size, interconnection or eligibility limits.
- Whether battery charging and exporting are treated differently from direct solar export.
Research your utility, not just your state
Solar export rules can differ between utilities in the same state and can change for new customers over time. Start with the Solar Export Rules by Utility comparison, then open the detailed Electric Utilities & Solar Rules directory and verify the current tariff with the utility before relying on it in a purchase decision.
The Home Solar Calculator currently uses an editable retail-rate assumption and does not silently treat every exported kWh as full retail value. See our methodology for details.