How Inverter Sizing Works In GridGap
The Inverter tab answers two related questions. First, how much continuous AC power the inverter must support. Second, how much short-term startup or surge stress it may need to survive when demanding appliances start.
What the Inverter tab is doing
A battery result on its own is not enough. The system still needs an inverter that can turn stored DC energy into usable AC power for the modeled load. This tab is where GridGap translates the appliance burden into inverter sizing outputs that are easier to compare against real hardware.
The inverter result is not only about the highest load number the app can find. It also reflects operating margin and surge behaviour, which is why the result usually includes both minimum values and recommended values.
Continuous inverter sizing
The first card, System Voltage, reminds you of the DC system context behind the inverter recommendation. This matters because the inverter result has to remain compatible with the battery arrangement used elsewhere in the scenario.
Minimum continuous inverter is the lower continuous output level the system needs to support the modeled running load. This is the narrow technical floor, not automatically the best practical choice.
Recommended inverter is the more practical planning answer. It allows for the margin that makes the result more realistic to live with. If the gap between the minimum and recommended values feels large, that usually means the app is protecting against comfort margin rather than chasing the smallest possible unit.
In practice, users should compare real hardware against the recommended value first and only fall back toward the minimum value if they understand exactly why the smaller choice is still acceptable.
Surge-related outputs
The next set of cards covers startup stress: Minimum surge, Recommended surge, and Worst-case surge. These are there because many loads do not behave like a steady resistive appliance. Motors, compressors, pumps, and similar devices can pull sharply higher power when starting.
Minimum surge is the lower surge threshold implied by the current assumptions. Recommended surge is the more comfortable planning level. Worst-case surge helps you see how severe the most demanding startup moment could be under the scenario's assumptions.
Surge assumptions is a useful honesty check. It reminds you that surge results are only as good as the appliance entries and assumptions behind them. If a scenario has weak or generic appliance data, the inverter result may still be directionally useful, but it should be read more cautiously.
Load percent and comfort margin
Inverter load percent helps show how hard the inverter is being pushed under the scenario assumptions. A higher percentage means less operating breathing room. A lower percentage usually means a more relaxed system with more comfort margin for real-world variation.
A high inverter load percent is not automatically wrong. It may still describe a workable setup. It does, however, tell you that the inverter side is closer to the limit and deserves closer review alongside surge behaviour and warnings.
As a rule, the Inverter tab should never be read in isolation. If inverter sizing looks tight, compare it with the Battery tab, the Warnings tab, and the appliance list that created the load in the first place.