Energy offset and bill offset calculator
Compare the share of kWh solar covers with the share of the bill it removes. Every default is invented.
Invented example, not a quote. The tariff, the monthly use shape and the monthly solar shape are placeholders. Replace the tariff with the customer's own. Credits carry forward within the year and any left at year end are lost (an invented rule).
| Result (one year) | Value |
|---|---|
| Energy offset = production ÷ annual use | - |
| Bill offset = (bill before − bill after) ÷ bill before | - |
| Bill before solar (USD) | - |
| Bill after solar (USD) | - |
| Fixed charges in a year (USD) | - |
| Ceiling on bill offset = 1 − fixed charges ÷ bill before | - |
| Credit lost at year end | - |
The monthly use and solar shapes are fixed invented patterns (summer-heavy use, summer-heavy solar). Real bills need the customer's own months and tariff. Taxes, riders, demand charges and time-of-use periods are not modelled. Illustrative; not a bill or a savings guarantee.