What the 1.5kW X1-MINI G4 offers

SolaX X1-MINI G4 1.5kW String Inverter (incl. WiFi and AFCI) sits in the sweet spot for smaller residential solar systems that need more capacity than an entry-level inverter but do not need the jump to a larger chassis or a more complex product family. It is a single-phase on-grid string inverter for simple domestic PV systems, using one MPPT and one string input, and it keeps the compact format that makes the X1-MINI G4 range attractive for tidy residential work.

The reason this variant matters is simple. Many households have roof space and energy use that make 1.5kW a better match than 1.1kW, especially when using today’s higher-output modules on a modest roof. That extra output gives breathing room for slightly larger arrays while preserving the family’s neat footprint, 5.2kg weight and straightforward installation. For homes that want a compact inverter with useful oversizing tolerance, the 1.5kW model often lands in a very practical place.

Why choose the 1.5kW model

The 1.5kW version supports up to 3kWp of recommended PV array power. That is important because it allows the inverter to work with a modern small domestic array rather than only the very smallest systems. SolaX also specifies 200% DC oversizing support for the family, a 50V start-up voltage and a 40 to 450V MPPT window on this variant. Taken together, those figures mean the inverter can make effective use of contemporary module power classes while still being correctly positioned for modest single-phase residential systems.

In practical terms, that makes the 1.5kW model a strong fit for small family homes, bungalows, compact retrofits, extensions, social housing projects and straightforward new installations where the roof is not huge but there is enough space to justify more output than the 1.1kW unit. It also means buyers are not forced into a larger inverter purely to accommodate slightly higher panel wattage or a few extra modules.

Key specifications with real-world value

• 1500W rated output with 6.5A output current for small domestic single-phase systems
• Up to 3kWp recommended PV array power with 200% DC oversizing support
• 40 to 450V MPPT range and 50V start-up voltage
• One MPPT and one string input with 16A maximum input current and 22A maximum short-circuit current
• Type II surge protection on both AC and DC sides
• Built-in export control function with optional meter or CT support
• IP66 ingress protection for exposed installation positions
• Natural cooling, under 1W night consumption and compact 290 x 206 x 120 mm dimensions

Those numbers matter because they affect how easily the inverter fits real installations. The 16A input current allowance is useful with modern modules. The 40 to 450V MPPT range keeps design options open for small strings. The 50V start-up voltage helps the inverter come online early in the day, while the IP66 enclosure supports more flexible siting. The result is a unit that is easy to deploy in residential settings where the wall area is tight but the specification still has to be credible.

Protection, control and residential practicality

SolaX includes a solid protective package across the X1-MINI G4 family, and the 1.5kW model benefits from that same approach. The datasheet lists active anti-islanding protection, over and under voltage protection, DC isolation protection, DC reverse-polarity protection, residual current detection, back-feed current monitoring, over-temperature protection, monitoring ground fault protection, AC overcurrent protection and AC short-circuit protection. For UK residential work, it also lists approvals including EN and IEC 62109-1 and -2, IEC 61727, EN 50549, G98 and G99.

That protection and approval set is commercially important. It means the inverter is not only compact and well sized, but also aligned with the kind of safety and compliance expectations installers and specifiers have for current single-phase PV hardware. Built-in export control is another practical benefit. On sites where export needs to be managed, optional meter or CT integration makes that easier to implement without immediately moving to a more complex system architecture.

Installation benefits of this variant

The 1.5kW X1-MINI G4 weighs 5.2kg and measures 290 x 206 x 120 mm, so it remains very manageable on site. That helps with cupboard walls, service areas, utility spaces and external mounting positions where bulkier inverters would be more intrusive. The platform uses nature cooling, which is helpful for noise-sensitive residential locations. Communication is listed as RS485, DRM and optional meter or CT support, and the broader family literature also highlights features such as shade optimisation, I-V curve diagnosis and rapid shutdown readiness.

For straightforward string design, one MPPT and one string input can be an advantage rather than a limitation. It keeps the system simple, avoids unnecessary complication and suits single-roof-plane arrays well. Where the roof is clean and uncomplicated, the 1.5kW model gives enough output headroom to be more versatile than the 1.1kW option while preserving that tidy one-string logic.

Where the 1.5kW version is stronger than the 1.1kW unit

The key difference is usable headroom. With support for up to 3kWp of recommended PV array power, the 1.5kW version can accommodate a larger small-array design. That matters when a homeowner wants to squeeze more value from limited roof space, or when panel wattages mean a modest array quickly reaches the limits of a smaller inverter. The 1.5kW model gives more breathing room without asking the buyer to jump to the 2.5kW version, which may be unnecessary if the roof area and project scope are still firmly in small-system territory.

It is therefore a very good compromise between compact size and everyday domestic usefulness. Installers who want a physically small inverter but do not want to be boxed into the lowest output range will find the 1.5kW variant commercially sensible. It is small enough to stay discreet and easy to fit, yet capable enough to work comfortably with a broader set of modest residential arrays.

Who should buy this inverter

This inverter suits buyers planning a small to lower-mid domestic solar system on single-phase supply, especially where the roof is straightforward and the design calls for one string. It also suits retrofit jobs where an ageing lower-output inverter needs replacing with a current model, but the system size still does not justify a move to a larger frame. For new builds, small homes and simple roof planes, it is a balanced option that avoids both under-specifying and over-specifying the inverter.

Because it remains an on-grid string inverter rather than a hybrid model, it is best for straightforward PV generation where the project priority is efficient solar conversion rather than integrated battery management at inverter level. On the right site, that simplicity is a benefit. It keeps costs and system complexity controlled while still delivering a modern feature set.

Final view

SolaX X1-MINI G4 1.5kW String Inverter (incl. WiFi and AFCI) is one of the most useful sizes in the range for smaller domestic installations. It gives a step up from the 1.1kW version by supporting up to 3kWp of recommended PV array power, yet it stays in the same compact, easy-to-handle housing. With Type II surge protection on both AC and DC sides, export-control capability, IP66 weather protection and the wider family’s intelligent design features, it is a well judged choice for buyers who want a compact residential inverter with more everyday flexibility.

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