Sizing hybrid inverters for self-consumption projects: Field notes on matching hybrid inverter size to real consumption.
The most common sizing error in hybrid projects comes from reading the datasheet instead of the load profile. A household that runs a heat pump all winter behaves very differently from one that cooks with induction twice a day.
Three field rules
- Size for the base load plus the longest simultaneous run, not the single highest peak.
- Keep some headroom for DC-coupled battery charging on winter days.
- Check the inverter's battery charge current against the battery's own limits.
When in doubt, model the worst week of the year, not the best day. The inverter that survives February is the one that keeps the customer happy.
| Sizing Variable | Engineering Check & Formula | Representative PV-PARTNER Hardware |
|---|---|---|
| Continuous AC backup power (kW) | P_inv >= P_base + max simultaneous inductive surge (heat pump / HVAC) | Deye SUN-6K/10K, Huawei SUN2000-6K/10K-LC0, Victron MultiPlus-II 48/5000 |
| DC/AC oversizing ratio & MPPT (A) | DC/AC 1.20x–1.40x; verify string I_mp <= MPPT max input current (13 A–18 A) | Jinko Tiger Neo N-Type 510W–720W paired with high-current MPPT inputs |
| Battery C-rate & charge current (A) | I_chg_max <= 0.5C–1.0C continuous BMS rating for full winter solar window recovery | Dyness DL5.0C (48V LV) or Huawei LUNA2000 / Fox ESS EP5-EP12 (HV) |
Hybrid Inverter & Battery Sizing Desk
Send us your load profile to verify DC/AC ratio, backup surge headroom, and BMS charge/discharge C-rate.
Frequently Asked Questions (FAQ)
How should I size a hybrid inverter for homes with heat pumps?+
Size for the continuous simultaneous winter load plus compressor startup margin rather than relying on isolated summer peaks.
Why check inverter battery charge current in Amperes instead of kW alone?+
Low-voltage and high-voltage hybrid inverters cap charge current in Amperes; matching voltage and current ensures full daytime recharge.
Can PV-PARTNER verify inverter-to-battery compatibility before I order?+
Yes. Reach out via our Contact page with your project load profile and our technical team will validate the BOM.
Author: Virginie Paulo (Senior PV Distribution & Regulatory Specialist) · Technical review: Hendryk Knuth (Technical Director, PV-PARTNER / YOFI SUN S.L.) · Regulatory & technical verification date: 4 November 2026. Prepared with AI-assisted drafting and verified against primary BOE, DGEG, and manufacturer documentation.