Net-zero balance calculator
One building, one year: does it pass an energy test, a carbon test, or neither?
A teaching aid. Every preset is invented, including the emission factors, which you must replace with a factor from your own dated source. The energy test is on a site basis (delivered energy against exported energy). The DOE zero energy definition uses a source basis, so a result here is not a certification. Embodied carbon and offsets are not included. Use a comma or a point for decimals. Avoid thousands separators.
| Result | Value |
|---|---|
| Solar used on site (kWh) | |
| Grid import (kWh) | |
| Export (kWh) | |
| Delivered energy: import plus gas (kWh) | |
| Energy test: delivered is no more than exported | |
| Net operational emissions (t CO2e) | |
| Carbon test: net emissions are zero or below | |
| Residual left to offset or remove (t CO2e) |
Net emissions = import x import factor + gas x gas factor - export x export credit factor. A negative number means credited exports exceed the building's own emissions on these factors.