How inverter sizing works
Continuous rating: load × 1.3 — a 30% margin keeps the inverter cool and long-lived. Surge: motor loads are counted at 3× while everything else is counted once; the inverter's peak rating must cover that sum or your AC will trip it on startup.
Match the array as well
If your panels are 7 kW, an inverter smaller than 7 kW will clip production at midday. Size to the larger of your load requirement and your array.
Why must the inverter be bigger than my load?
Two reasons: continuous headroom (25–30%) so it never runs at its limit, and startup surge — motors and compressors draw 2–3× their rated power for a moment when starting.
Hybrid, on-grid or off-grid — which type do I need?
Grid available and you want outage backup: hybrid. Grid available, no backup needed: on-grid (cheapest, but shuts down in outages). No grid at all: off-grid with batteries.
Should the inverter match my solar array size too?
Yes — the inverter should be at least as large as the array's kW so daytime generation is never clipped.