SolaX X1 inverters: single-phase hybrid models explained

SolaX's X1 line is the maker's single-phase family for UK homes: hybrid inverters that manage panels and a battery together, smaller on-grid Mini models, roof-mounted Micro microinverters, and the all-in-one X1-IES cabinet that bundles inverter and battery in one unit. The flagship hybrid, the X1-Hybrid G4, comes in 3.0kW, 3.7kW, 5.0kW, 6.0kW and 7.5kW ratings¹, the X1-MINI G4 runs from 0.6kW to 3.3kW², and the X1-Micro series covers 0.75kW to 2.4kW across four microinverter types³. The newest hybrid, the X1-VAST, extends to 10kW⁴.

For a household weighing energy independence, the X1 hybrids are the models that matter, because they are the ones that store solar in a battery and can run a home off-grid through an EPS output. But the range carries real dependencies too: the longest warranty terms require a permanent connection to SolaX's cloud, and the smart functions run through the maker's own platform. This page sets out the models, the warranty terms, the efficiency and safety features, the prices and the stock position, so you can see what an X1 buys and what it ties you to.

Overview of the X1 line: hybrid, micro and mini versions

The X1 badge covers four quite different products, and knowing which is which avoids the most common buying confusion. The X1-Hybrid G4 is a single-phase hybrid inverter for storage-ready homes, available in 3.0kW, 3.7kW, 5.0kW, 6.0kW and 7.5kW¹. The X1-MINI G4 is a single-phase residential on-grid inverter in nine outputs from 0.6kW to 3.3kW, with 16A input, optional AFCI protection, an optional AC auxiliary power supply and natural cooling². The X1-Micro series are microinverters, from 0.75kW to 2.4kW, which mount at the panels rather than on a wall³. The X1-IES is an all-in-one unit combining inverter and battery, in 2.5kW to 8.0kW models with IP66 ingress protection and a 10-year battery warranty¹⁰.

SolaX also sells X1 models outside the UK: the J1 Hybrid is Japan-exclusive³, and the A1 Hybrid G2, a single-phase hybrid with up to 98% peak efficiency that can run up to 4 systems in parallel, is aimed at other markets¹¹. UK buyers should check that any model quoted is one sold and supported here. For the background on how these types differ, see hybrid inverters, microinverters and the wider solar inverters guide.

Single-phase hybrids: the X1-VAST and X1-Hybrid G4

The X1-VAST is SolaX's larger single-phase hybrid, listed in 5kW, 6kW, 8kW and 10kW ratings⁴. Its distinguishing features are backup strength and off-grid intent: it provides up to 200% EPS output for 10 seconds with an ultra-fast switchover time under 10ms, supports wireless meter compatibility, and is built, in SolaX's words, for "seamless integration into microgrids and generators for reliable off-grid use"⁴.

For a home that wants genuine power-cut resilience rather than token backup, that 200% EPS figure matters: it means short surges, such as a motor starting, can be carried from battery rather than tripping the system.

The X1-Hybrid G4 sits below it, designed for single-phase homes in 3.0kW to 7.5kW models, with two MPPTs, IP65 protection and fast switchover on EPS output⁵. The datasheet gives a maximum efficiency of 97.6%, natural or smart air cooling, and compatibility with both lithium and lead-acid batteries¹². The product page confirms it is VPP-ready and supports battery integration alongside heat pump and smart EV charger integration¹³. The two models overlap at 5kW to 7.5kW; the VAST is the one to look at where backup power and off-grid operation are the priority, the Hybrid G4 where the aim is solar self-consumption with battery storage on a standard single-phase connection. Sizing guidance is in what size solar system a home needs.

Five-year guarantee as standard and its conditions explained

SolaX's warranty terms, effective from 10 September 2026 for products sold or installed on or after that date, give the X1-Hybrid G4, X1-Fit G4, X1-IES, X1-VAST and related models a 5-year standard warranty, starting from the earlier of the first installation date or 6 months after the production date⁷. The X1-MINI G4, X1-Boost G4, X1-Smart G2 and several X3 models carry 7 years standard⁷. Accessories, including meters, CTs, pocket WiFi/LAN/4G dongles, data hubs and EPS boxes, carry 2 years⁷.

The headline condition is the cloud upgrade. If an inverter is connected to SolaX cloud and generation data has been successfully uploaded to the SolaX server, the warranty on the 7-year models is freely upgraded to a 10-year standard warranty¹⁴.

Registration and claims have firm deadlines:

1. Register the product online within 90 days of the commissioning date; if not registered in time, the warranty period is calculated as the production date plus 6 months¹⁵.
2. The warranty start date is the installation or commissioning date, the purchase invoice date, or the shipment date from the factory if no registration is completed¹⁵.
3. Claims must be filed within 4 weeks of the failure date¹⁵.
4. A replacement inverter receives the remaining balance of the original warranty, and if less than 12 months remain, SolaX extends the replacement warranty to a minimum of 1 year¹⁵.

Protection and performance: IP67 rating, Rapid Shutdown and more

Efficiency across the X1 line runs in the high nineties. The X1-Micro 2 in 1 achieves 98.6% peak efficiency⁶, the X1-Hybrid G4 datasheet lists a maximum efficiency of 97.6%¹², and the X1-Micro series as a whole is quoted at 97.5% maximum, with an extra 1.5% efficiency gain attributed to ultra-low start-up voltage³. The X1-Hybrid G4 charges and discharges batteries at up to 97% efficiency¹. These are maker figures, measured under test conditions rather than in a lived-in roof, but they are consistent across the range.

Weather protection varies by where the unit sits:

• X1-Micro series: IP67, confirmed model by model for the X1-Micro 750, 800, 900, 1000, 1200 and 1300, the 4 in 1 versions and the G2 generation³. That is the rating that lets a microinverter live under the panels on the roof.
• X1-Hybrid G4 and X1-Fit G4: IP65, suited to wall mounting⁵.
• X1-Lite LV: IP65, a single-phase low-voltage hybrid¹⁹.
• X1-IES all-in-one: IP66¹⁰.

Safety features are strongest on the micro and on-grid models. The X1-Micro 2 in 1 has an NEC-compliant Rapid Shutdown function⁶, and the X1-Boost G4 offers optional AFCI protection and is Rapid Shutdown ready³. On the X1-MINI G4, AFCI is optional², and the X1 Smart range includes AFCI support²⁰. AFCI detects the DC arc faults that cause panel-side fires; whether it is fitted is a question to ask of any quote. Fire and electrical safety generally is covered in solar PV safety.

Beyond exporting: how the X1 supports peak shaving and VPPs

The X1 hybrids are built to do more than export surplus. The X1-Hybrid G4 is VPP-ready, meaning it can be enrolled in a virtual power plant where an aggregator uses pooled home batteries to balance the grid, usually in return for payments¹. The X1-Fit G4 is likewise listed as VPP ready, with two charging periods available for time-of-use tariff control¹⁸. SolaX's own three-phase X3-Hybrid G4 datasheet confirms the same VPP readiness across the wider platform²¹.

On raw capability, SolaX states up to 200% PV oversizing, up to 110% AC output, and up to 97% charging and discharging efficiency for the X1-Hybrid G4²². PV oversizing of 200% means a 5kW inverter can take a 10kW array, which spreads generation across the day at the cost of clipping the midday peak; the 110% AC output recovers some of it. The X1-VAST adds up to 200% EPS output for 10 seconds with under 10ms switchover⁴, and the X1-IES accepts up to 200% PV input power²³.

Peak shaving, where the battery covers short demand peaks so the home draws less from the grid at expensive times, appears in the wider SolaX ecosystem: the J1-EVC-6K EV charger "supports peak shaving and valley filling for optimal energy use"²⁴. The practical point for a household is that these functions need the inverter, a battery and the monitoring platform working together, and VPP participation in particular means handing some control of your battery to a third party. What that trade-off looks like is covered in adding battery storage and monitoring a solar PV system.

Prices and stock, starting with the £250 X1-1.1 Mini

SolaX publishes no UK list prices for the X1 range; the figures that exist are distributor listings, and they differ between listings for the same product. The table below gathers the inverter-only prices from those listings. The VAT position is not stated in the listings, and installed system costs come from installer quotes after a survey.

For context on where the X1 line sits in the market, SolaX positions the X1-Lite LV as a single-phase low-voltage hybrid for tighter budgets²⁸, and describes its affordable inverter alternatives for UK homes around smaller X1 formats²⁹. A broader comparison of the brand against its rivals is at SolaX hybrid inverters and SolaX vs Growatt.

Fitting the X1: a one-person setup and greater energy self-sufficiency

The all-in-one end of the X1 family is engineered to cut installation time. The X-ESS G4, SolaX's all-in-one cabinet, is described as "quick installation by one person in 30 minutes" with an all-in-one, plug-and-play design³⁰. The X1-IES is likewise all-in-one and plug-and-play³¹, modular and pre-configured to reduce wiring and commissioning time, with parallel expansion and integration with other home electrification devices³², and modular expansion up to 40kWh of storage²³. The X1-Fit G4 offers quick configuration with a U-disk¹⁸. None of this makes an X1 a DIY job: grid-connected inverters must be installed by a certified installer, and the process from survey to handover is covered in solar panel installation.

When something goes wrong, diagnosis runs through SolaX. Support requests ask for:

• the inverter model and operating mode
• the time of occurrence and recovery behaviour
• the serial number from the product label or SolaXCloud³³

Fault codes are read against the maker's own list, and installation guidance emphasises safety features including AFCI support²⁰.

The independence picture is mixed, and it is worth stating plainly. An X1 hybrid with a battery reduces dependence on the grid and on import electricity: the X1-VAST in particular is built for microgrid and generator integration for off-grid use⁴. But three dependencies remain. The inverter itself is a single manufacturer's product, with fault diagnosis and warranty claims running through SolaX. The 10-year warranty upgrade requires a permanent connection to SolaX cloud with generation data uploaded¹⁴, so the longest cover is conditional on the maker's servers staying up and the household staying connected. And VPP participation, where offered, places a third party between the householder and their own battery. A home with an X1 hybrid is more self-sufficient than a home with panels alone, but it is not independent of the companies behind the equipment. The wider picture is in solar panels and household energy independence.