Sungrow SG350HX vs Huawei SUN2000-330KTL-H1 vs Growatt MAX 350 KTL3-XL2: 1500V String Inverter Comparison
Procurement Verdict: Choosing Between 330–350 kW 1,500 V DC Three-Phase String Inverters
Choose the Sungrow SG350HX (352 kVA @ 30°C / 320 kVA @ 40°C) for large industrial rooftops and utility blocks requiring maximum MPPT granularity (12 or 16 MPPTs, 2 strings/MPPT, 30 A or 40 A per MPPT) and peak conversion efficiency of 99.02% (98.8% European efficiency) with PLC/RS485 telemetry.
Choose the Huawei SUN2000-330KTL-H1 (330 kW / 330 kVA rated at 40°C) when ambient temperatures regularly reach 40°C without kVA derating, when pairing 4–5 strings per MPPT (up to 65 A per MPPT across 6 or 8 MPPTs) on uniform ground-mount or flat-roof arrays, and when Huawei's MBUS PLC power-line communication eliminates separate RS485 signal trenching.
Choose the Growatt MAX 350 KTL3-XL2 (350 kW / 350 kVA) when rooftop structural weight or manual rigging limits favor the lightest chassis in the class (~108 kg vs 112 kg for Huawei and ~116 kg for Sungrow) while maintaining 15 MPPTs (2 strings/MPPT, 30 A–40 A/MPPT) and 99.0% max / 98.8% Euro efficiency. On a 25-year China-to-UK industrial rooftop TCO basis (420 kWp DC, 378,000 kWh/yr Year-1 yield, 8.00% WACC), the inverter + AC/DC BoS + ENA G99 protection sub-scope (£31,800 CapEx, £1,100/yr OpEx, £7,200 yr-13 replacement) clears a 0.7254-year simple payback, 138% IRR, £378,763.57 NPV, and £0.0145/kWh LCOE, whereas a full-plant CapEx band of £1,050,000 with £18,000/yr OpEx sits right at break-even (NPV -£1,492.01, IRR 7.99%, simple payback 12.09 years, LCOE £0.3299/kWh).
1. Side-by-Side 350 kW-Class Technical Specification Comparison
All three models are transformerless three-phase 1,500 V DC string inverters designed for utility-scale solar blocks and large industrial rooftops paired with 800 V AC step-up transformers or dedicated industrial LV/MV switchboards. The table below details the exact parameters from Tradvolt's UK plant rooftop TCO dossier and C&I procurement SOP.
| Specification | Sungrow SG350HX | Growatt MAX 350 KTL3-XL2 | Huawei SUN2000-330KTL-H1 |
|---|---|---|---|
| Manufacturer / Brand | Sungrow Power Supply Co., Ltd. (SG Series) | Growatt New Energy (MAX Series) | Huawei Digital Power (FusionSolar) |
| Rated AC Output Power / Apparent Power | 350 kW class: 352 kVA @ 30°C / 320 kVA @ 40°C | 350 kW / 350 kVA | 330 kW / 330 kVA @ 40°C (often paired to form a 350 kW AC equivalent block) |
| Maximum DC Input Voltage | 1,500 V DC | 1,500 V DC | 1,500 V DC |
| MPPT Operating Voltage Range | 500–1,500 V DC | 500–1,500 V DC | 500–1,500 V DC |
| Number of Independent MPPTs | 12 or 16 MPPT (sub-variant dependent) | 15 MPPT | 6 MPPT (8-MPPT variant also listed in C&I SOP) |
| Strings per MPPT & Max Current per MPPT | 2 strings/MPPT; 30 A or 40 A per MPPT | 2 strings/MPPT; 30 A–40 A per MPPT | 4–5 strings/MPPT; up to 65 A per MPPT |
| Max Efficiency / European Efficiency | 99.02% max / 98.8% Euro | 99.0% max / 98.8% Euro | 99.0% max / 98.8% Euro |
| Ingress Protection & Cooling | IP66; Smart Forced Air cooling | IP66; Smart Forced Air cooling | IP66; Smart Air cooling |
| Unit Weight | ~116 kg | ~108 kg | 112 kg |
| Communication Interface | PLC / RS485 | RS485 / PLC | MBUS (Power Line Communication) |
| Compliance & Safety Standards | IEC 62109-1:2010, IEC 62109-2:2011, EN 50549-1/-2, VDE-AR-N 4105/4110, UKCA, ENA G99 (issue 1 amd 9, 2024), EN 61000-6-2/-6-4 | IEC 62109-1:2010, IEC 62109-2:2011, EN 50549-1/-2, VDE-AR-N 4105/4110, UKCA, ENA G99, EN 61000-6-2/-6-4 | IEC 62109-1:2010, IEC 62109-2:2011, EN 50549-1/-2, VDE-AR-N 4105/4110, UKCA, ENA G99, EN 61000-6-2/-6-4 |
2. 25-Year China-to-UK Plant Rooftop Landed Cost & TCO Comparison
In Tradvolt's China-to-UK 350 kW plant rooftop study (420 kWp DC array at 1.2× DC/AC ratio, 900 kWh/kWp/yr PVGIS SARAH2 baseline yield = 378,000 kWh Year-1 generation degrading 0.5%/yr, 70% self-consumption at £0.30/kWh imported tariff and 30% exported under Ofgem Smart Export Guarantee at £0.075/kWh escalating 4.0%/yr, 25-year horizon, 8.00% WACC), procurement teams can evaluate either the standalone inverter + electrical BoS package or the full turnkey plant CapEx band. Both accounting scopes are presented side-by-side below.
| Cost / Financial Metric | Inverter + Electrical BoS + G99 Sub-Scope (350 kW Unit) | Full Plant Scenario Model Output (420 kWp DC / 350 kW AC) |
|---|---|---|
| Shortlisted Equipment | Sungrow SG350HX / Growatt MAX 350 KTL3-XL2 / Huawei SUN2000-330KTL-H1 | Sungrow SG350HX / Growatt MAX 350 KTL3-XL2 / Huawei SUN2000-330KTL-H1 |
| Year-0 Landed CapEx Breakdown | £31,800 total: FOB China £11,200 + ocean freight & customs £2,150 + AC/DC BoS switches & cabling £9,850 + ENA G99 protection & witness test £8,600 | £1,050,000.00 (illustrative full-plant Year-0 CapEx band; individual EXW, Felixstowe/Southampton freight, UKGT duty, and 20% VAT lines marked PENDING — lookup) |
| Year-1 Annual OpEx | £1,100/yr (preventive thermography, fan/SPD spares reserve, monitoring) | £18,000.00/yr escalating at 2.0%/yr (reaching £28,951.87 in Year 25) |
| Mid-Life Overhaul / Replacement | Year-13 inverter replacement reserve: £7,200 | Embedded in annual OpEx reserve; Year-25 residual value = £0 |
| Total Undiscounted Cost / PV of Costs (25 yr) | Inverter sub-scope cost stream over 25 years | Undiscounted cost: £1,626,545.40 / PV of costs: £1,278,132.64 |
| Total Undiscounted Benefit / PV of Benefits (25 yr) | Year-1 gross electricity savings: £87,885.00 | Undiscounted benefit: £3,414,016.01 / PV of benefits: £1,276,640.63 |
| Net Present Value (NPV @ 8.00% WACC) | £378,763.57 | -£1,492.01 (knife-edge break-even; £10k–£15k CapEx reduction turns NPV positive) |
| Internal Rate of Return (IRR) | 138% | 7.99% (0.0799, vs 8.00% hurdle rate) |
| Simple Payback / Discounted Payback | Simple payback: 0.7254 years | Simple payback: 12.09 years / Discounted payback: not reached within 25 yr |
| Levelized Cost of Energy (LCOE) | £0.0145 / kWh (inverter + BoS share) | £0.3299 / kWh (full-plant £1.05M CapEx scenario) |
3. When to Choose SG350HX vs SUN2000-330KTL-H1 vs MAX 350 KTL3-XL2
3.1 MPPT Granularity vs High-Current String Consolidation
- Multi-MPPT Architecture (Sungrow SG350HX & Growatt MAX 350 KTL3-XL2): The SG350HX provides 12 or 16 MPPTs and the MAX 350 KTL3-XL2 provides 15 MPPTs, each accepting 2 strings per MPPT at 30 A to 40 A per MPPT. Dedicating 1 MPPT to every 2 strings isolates partial shading on multi-pitched industrial roofs and supports high-current 182 mm / 210 mm TOPCon and HPBC modules (such as LONGi Hi-MO 7 or Jinko Tiger Neo 3.0 670 W).
- Consolidated High-Current Architecture (Huawei SUN2000-330KTL-H1): Huawei uses 6 MPPTs (or 8 MPPTs) with 4–5 strings per MPPT and up to 65 A per MPPT. On unshaded, uniform-tilt arrays, grouping 4–5 strings onto a 65 A tracker simplifies DC runs while Huawei's MBUS PLC sends telemetry over the AC power lines.
3.2 Thermal Derating (30°C vs 40°C) & Grid-Code Compliance
The Sungrow SG350HX is rated at 352 kVA @ 30°C and derates to 320 kVA @ 40°C, whereas the Huawei SUN2000-330KTL-H1 holds its full 330 kW / 330 kVA rating at 40°C. For UK and EU grid connections above 16 A per phase, all three models require test certificates for IEC 62109-1:2010, IEC 62109-2:2011, EN 50549-1/-2, VDE-AR-N 4105/4110, and ENA Engineering Recommendation G99 (Issue 1, Amendment 9, 2024). Under WCO HS 2022 heading 8504.40, UK Global Tariff and EU TARIC duty rates are marked PENDING — lookup, with UK import VAT at 20% of (CIF + duty).
4. Related Tradvolt TCO Dossiers & Engineering Guides
- On-Grid Inverter 350 kW (Sungrow SG350HX / Growatt MAX 350 KTL3-XL2 / Huawei SUN2000-330KTL-H1) — CN → UK Plant Rooftop TCO & Landed Cost
- Solar PV + Battery Storage C&I Procurement SOP — Vendor Shortlist & Compliance
- Import On-Grid Inverter (Sungrow SG350HX) from China to New Zealand — Stadium Rooftop TCO
- Import 350 kW On-Grid Inverter from China to Bahrain — Logistics-Rooftop TCO & Landed Cost
- Maintenance Process Guide: Inverter Reactive Power for CN→UK Corridor