Can I oversize the PV array on a G98 inverter, and what rating counts for G98?
Short answer
Yes. G98 and G99 thresholds use the inverter's AC Registered Capacity, not the array's DC kWp, so a 3.68 kW inverter can sit behind a larger array within the manufacturer's DC input limits. The aggregate AC capacity of all PV and battery inverters on the connection point is what counts, and G99 lets capacity be software-limited.
Last checked 24 September 2026 · 2 sources
In more detail
- G98: 16 A/phase = 3.68 kW single-phase; aggregate of all inverters at one connection point.
- G99 definition: Registered Capacity can be limited (e.g. by software) below Intrinsic Design Capacity for SGI procedures.
- Check inverter max DC input power, max input current per MPPT and voltage window; clipping losses rise with ratio.
- The MCS performance estimate uses array kWp (data-plate Wp) x Kk x SF - AC clipping is not modelled.
The facts, dated
- 01G98 Registered Capacity basis — AC, 16 A per phase at 230 V
standard · GB · checked 24 September 2026 · dcode.org.uk
- 02MCS estimate uses sum of module data-plate Wp — kWp x Kk x SF
standard · UK · checked 24 September 2026 · MCS
What we saw in the field
[QA review 2026-09-24] C2-2 AGREES; C2-3 12 kW peak is above the 11.04 kW AC rating - not AC generation unless more inverters were added. | Earlier notes: Customer 2: 13.5 kWp on ~11 kW Powerwall inverter (deliberate DC oversizing) peaking ~12 kW - consistent (peak reported slightly above nominal; check inverter spec).
Sources
- dcode.org.uk — dcode.org.uk/assets/250307ena-erec-g98-issue-2-(2025).pdf
- MCS — mcscertified.com/wp-content/uploads/2026/03/MIS-3002_Solar-PV-Systems-V6.0-Final…
Last checked: 24 September 2026