UK SolaX X1-Hybrid G4 Inverter Guide

Residential solar photovoltaic installations across the United Kingdom are increasingly transitioning from simple grid-tied generation to fully integrated hybrid systems capable of co-locating solar generation with high-voltage battery storage. In domestic properties with constrained roof space or split orientations (such as east-west semi-detached dwellings), inverter flexibility, wide tracking windows, and rapid emergency power backup are essential system selection criteria.

The SolaX X1-Hybrid G4 (Generation 4) is a single-phase residential hybrid inverter platform engineered specifically to meet these domestic performance requirements. Available in ratings spanning 3.0kW / 3.7kW / 5.0kW / 6.0kW / 7.5kW, the platform integrates dual independent MPPT channels, generous photovoltaic array oversizing allowances, and uninterruptible power supply (UPS) grade emergency backup functionality.

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• Power Ratings: Covers single-phase residential outputs of 3.0kW, 3.7kW, 5.0kW, 6.0kW, and 7.5kW.
• Array Oversizing: Supports up to 200% pv oversizing and up to 110% ac output, maximizing self-consumption during shoulder months.
• MPPT Voltage Window: Features a wide DC operational tracking window spanning from mppt voltage range 70~550 v with dual independent trackers.
• High-Current Handling: Handles up to max. input current per mppt 16 a/16 a, accommodating modern high-output photovoltaic modules.
• UPS-Grade EPS Backup: Delivers emergency power supply switchover within 10 milliseconds, supported by up to 150% eps output for 10s overload capability.
• High-Voltage Battery Pairing: Couples directly to high-voltage lithium battery systems, minimizing DC current losses compared to conventional low-voltage architectures.
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Inverter Array Sizing & Electrical Input Parameters

A primary advantage of the SolaX X1-Hybrid G4 series is its generous DC array sizing allowance. SolaX permits 200% pv oversizing and up to 110% ac output, enabling installers to connect solar arrays rated at twice the inverter's nominal AC output power. In the UK climate, where diffuse light conditions dominate during autumn and winter, substantial array oversizing ensures the inverter operates at peak conversion efficiency for significantly more hours each year.

The platform's dual Maximum Power Point Trackers (MPPT) operate across an extensive DC input voltage window:

Each tracker channel accepts up to max. input current per mppt 16 a/16 a. This generous current allowance ensures compatibility with modern N-type TOPCon and heterojunction (HJT) solar panels, whose operating currents routinely challenge older generation inverter trackers.

```
SOLAX X1-HYBRID G4 DUAL MPPT ARCHITECTURE
══════════════════════════════════════════════════════

East Roof Pitch (String 1) ──► MPPT 1 (70V-550V / 16A) ──┐
│
West Roof Pitch (String 2) ──► MPPT 2 (70V-550V / 16A) ──┼──► Hybrid Inverter
│ (3.0kW - 7.5kW)
High-Voltage Battery Pack ──► High-Voltage DC Port ──┘
```

The tracker voltage window spans mppt voltage range 70~550 v, providing exceptional low-light harvesting capability. With string activation occurring at low voltages, the inverter begins harvesting energy earlier in the morning and continues generating later into the evening than inverters requiring higher string activation thresholds.

Emergency Power Supply (EPS) & Grid Outage Resilience

Grid reliability concerns have driven increased domestic demand for whole-home or critical-load backup power. The SolaX X1-Hybrid G4 incorporates dedicated EPS (Emergency Power Supply) circuitry designed to isolate the home from the utility grid during a power cut.

Key backup engineering capabilities include:

• Rapid Switchover Latency: During a mains grid failure, the internal automatic transfer switch transfers critical domestic circuits to battery power in less than 10 milliseconds (<10ms). This ultra-fast transition meets true uninterruptible power supply (UPS) standards, preventing sensitive electronic equipment, desktop computers, and home routers from rebooting during an outage.
• Surge Overload Capacity: Electric motors, refrigerators, and heat pumps draw significant inductive surge currents when starting. SolaX engineers the EPS circuit to deliver up to 150% eps output for 10s. On the entry-level 3.0kW unit, the system delivers peak eps output power 6000 va 10 s to accommodate motor inrush currents before settling into its continuous rated eps output power 3000 va operating mode.
• Higher Output Surge Scaling: On larger single-phase models, surge capacity scales proportionately: the 5.0kW unit delivers peak eps output power 7500 va 10 s against rated eps output power 5000 va, while the 6.0kW model supplies peak eps output power 9000 va 10 s against rated eps output power 6000 va.

```
GRID POWER OUTAGE TIMELINE (<10ms SWITCHOVER)
══════════════════════════════════════════════════════════
Grid Normal ──► Mains AC Active (On-Grid Hybrid Operation)
Grid Failure ──► Inverter Detects Loss of Mains (Anti-Islanding)
Transfer ──► EPS Relay Engages (<10ms Latency / UPS Grade)
EPS Backup ──► Up to 150% Surge for 10s, then Continuous Rating
```

UK Grid Compliance: ENA G98 vs G99 Applications

When connecting a SolaX X1-Hybrid G4 inverter to the UK electricity distribution network, installers must ensure compliance with Energy Networks Association (ENA) engineering recommendations:

ENA EREC G98 (Fast-Track De Minimis Connection)

Under ENA G98, single-phase micro-generators with an aggregate AC export capacity not exceeding 3.68 kW (16 A single-phase limit) may be connected under a statutory "fit and inform" procedure. Installers may commission the X1-Hybrid-3.0 or X1-Hybrid-3.7 (configured for 16A export limit) and notify the local District Network Operator (DNO) within 28 days of commissioning without requiring prior approval.

ENA EREC G99 & G100 Export Limitation

Larger models in the range—specifically the 5.0kW, 6.0kW, and 7.5kW units—exceed the 3.68kW single-phase threshold. These units cannot be commissioned under G98 fast-track rules and require a formal prior G99 connection application to the local DNO (such as UK Power Networks, National Grid Electricity Distribution, Scottish and Southern Energy Networks, or SP Energy Networks). Alternatively, installers can integrate an ENA G100 compliant export limitation scheme to clamp maximum export at 3.68kW while utilizing full 5kW to 7.5kW capacity for on-site self-consumption and battery charging.