Fox ESS F series inverters: models and specifications

The Fox ESS F Series is a single-phase PV inverter, which means it converts what a solar array generates into electricity a home can use, and it does that job only. There is no battery input. Fox ESS lists it under PV inverters alongside the S Series, the G Series and the three-phase V Series, while the hybrid work is done by other families entirely¹.

Two models are sold in the UK. The F5000 is listed at £354.00 plus VAT and the F3600 G3 at £357.00 plus VAT, both dated 19 September 2026². A second listing for the F3600 G3 shows £360.00 plus VAT, so the two documents disagree by £3 and neither has been ruled the correct one². These are supply-only prices. Installation, mounting, cabling and commissioning sit outside them and are quoted by an installer.

The F Series G2 datasheet lists two MPP trackers and states China as the country of manufacture³. Fox ESS describes the range as a flexible configuration with a plug-and-play set-up¹.

What the F Series is: a single-phase string inverter for PV-only homes

A string inverter takes the direct current from a row of panels wired together and turns it into alternating current for the house and the grid. Fox ESS files the F Series and the G Series under the heading "single-phase PV inverter", which separates them from the hybrid models that accept a battery on the same box¹. The F Series G2 datasheet carries the same description, "single-phase inverter", and adds the country of manufacture as China³.

This is the most common arrangement in home solar. Single-phase string inverters are described in industry guidance as the more common type of inverter used in residential solar energy systems⁵, and a PV-only system is set out as solar modules, a grid-connected inverter, a connection to the utility grid and no battery storage⁶. That last item is the whole point of the category: it is the cheapest way to get a roof generating, and it leaves storage for later or for never.

The F Series sits in a market where several brands sell the same shape of product. Sunsynk lists a 3.6kW single-phase string inverter and a 5kW unit for solar-only installations⁷, and Canadian Solar lists single-phase residential string inverters⁹. What distinguishes one from another at this level is price, tracker count, monitoring and how the maker handles warranty and spares, not the basic function.

For a household, the F Series is a component rather than a system. It does not generate anything on its own, it does not store anything, and it does not decide when the home uses its own power. It converts, and it reports. Everything else in the installation, from the panels to the consumer unit to the meter, sits around it.

The range at a glance: 3.6kW and 5kW G3 models

The UK listings show two F Series models: the F3600 G3 and the F5000². The numbers indicate rated output, so the F3600 G3 is the smaller unit and the F5000 the larger, and the G3 suffix marks the revision of the F3600. Both are single-phase, both are PV-only, and both carry two MPP trackers on the G2 datasheet³.

The price relationship is worth noting because it runs the opposite way to what most people expect: the smaller F3600 G3 is listed £3 higher than the larger F5000². That is not a mistake in the listing so much as a reflection of how distributor pricing works, where a newer revision and stock levels matter more than the output figure. A second listing puts the F3600 G3 at £360.00 plus VAT, so the gap between the two models is somewhere between nothing and £6 depending on which document is read².

Sizing is the decision that matters more than the price difference. A 3.6kW inverter suits a smaller array, and a 5kW unit suits a larger one or a home that expects to add panels. The inverter's rating sets the ceiling on how much the array can push through at once, and an undersized inverter clips output on the brightest days while an oversized one spends more of its life at part load. The wider question of matching array size to a home is covered in what size solar system does a home need.

Specifications and rated power: 3.6kW to 5kW, dual tracker

The published specification for the F Series G2 gives two MPP trackers and China as the country of manufacture³. Fox ESS describes the range as offering flexible configuration and a plug-and-play set-up¹, and the Dutch product page repeats that description as "flexibele configuratie"¹⁰. Those are the maker's own words about its own product, and they describe installation convenience rather than performance.

For context on what a rated figure means, the Fox ESS H1 G2 and AC1 G2 hybrid inverters are listed at 3000W, 4600W and 5000W rated output depending on model¹¹, and the same 5000W figure appears on the H1 G2 datasheet¹². The F Series sits in the same band. Rated output is the continuous figure the unit is designed to deliver, not a peak, and it is the number an installer uses when matching the inverter to the array.

Two trackers is the specification that changes what a roof can do. A tracker, or MPP tracker, is a separate input that finds the best operating point for the panels connected to it. With two, an array split across two roof aspects can be wired as two strings, each optimised independently, rather than averaged into one. The F Series G2 datasheet lists two³, the H1 G2 and AC1 G2 list two¹², and the ES G2 hybrid lists two¹³. The KH and KA hybrid series goes further with three or four MPPTs¹⁴.

What the datasheet does not give is a full efficiency curve, a weight, an IP rating or a warranty term for the F Series specifically. Those are the figures a buyer would normally check, and their absence from the published material is itself worth knowing: the specification available for this range is thinner than for the hybrid families, where Fox ESS publishes fuller datasheets.

Prices: £354 to £360 plus VAT from UK distributors

The UK price picture for the F Series is narrow and comes from a single distributor listing dated 19 September 2026. The F5000 is shown at £354.00 plus VAT and the F3600 G3 at £357.00 plus VAT, with a second entry for the F3600 G3 at £360.00 plus VAT².

Three things need saying about those numbers. They are supply-only, so they cover the box and nothing else. They are quoted plus VAT, and the VAT treatment of a domestic solar installation is a matter for the installer's invoice rather than the trade listing. And they are one distributor's prices on one date, not a market range.

For scale within the same catalogue, the Fox ESS S Series runs from £165.00 plus VAT for the 1.5kW unit to £249.00 plus VAT for the 3.0kW, the T Series three-phase units run from £588.00 plus VAT for the 6.0kW upwards, and the H3 Smart 6.0kW hybrid is £1,194.00 plus VAT². The F Series sits between the small S Series and the hybrid ranges, which is where a mid-size PV-only inverter belongs.

The installed cost of a solar system is a different figure entirely, and the inverter is one line in it. Panels, mounting, scaffolding, DC and AC cabling, labour and certification make up the rest. How much do solar panels cost in the UK sets out the whole-system picture, and the inverter's share of it is modest.

Where the F Series fits in the Fox ESS line-up

Fox ESS sells several inverter families into the UK, and the F Series is the plainest of them. The split is between PV inverters, which only convert, and hybrid inverters, which convert and manage a battery.

The PV side covers the S Series at 0.7 to 3.3kW¹, the G Series as a single-phase PV inverter¹, the F Series, and the V Series, which is a three-phase inverter¹⁵. The M Series microinverters sit at module level and are suitable for outdoor installation with a plug and play set-up¹⁶.

The hybrid side is where most of the current development sits. The KH and KA Series is described as a single-phase hybrid inverter and pairs with Fox ESS high-voltage batteries including the EP, EQ and CQ ranges¹⁴, with an EPS output when a battery is fitted¹⁷. The H1 G2 and AC1 G2 are listed as single-phase hybrid/AC inverters¹¹, and the ES G2 is a low-voltage hybrid inverter¹³. The EQ Battery Range pairs with compatible Fox ESS hybrid inverters including H1 G2 and K Series, H3 Smart and H3 Pro¹⁸.

That structure explains the F Series' position. It is the entry point for a home that wants generation without storage, and it is deliberately not upgradeable to a battery on the same unit. A household that expects to add storage later is looking at a different family, and hybrid solar inverters explains what changes when the battery sits on the DC side of the inverter. The wider Fox ESS range is set out in Fox ESS inverters.

Dual tracker: what two MPPTs mean for your roof

Two MPP trackers is the F Series' most useful specification for a real roof. A tracker is an input that continuously adjusts the electrical load on the panels connected to it so they run at their best operating point. Panels on a south-facing slope and panels on an east-facing slope reach their best point at different times and under different conditions, and a single tracker has to compromise between them.

With two trackers, those two groups can be wired as separate strings. Each runs at its own optimum, and the losses that come from averaging a shaded or differently angled group into a single input are avoided. The F Series G2 datasheet lists two MPP trackers³, and the same count appears on the H1 G2 and AC1 G2¹² and the ES G2¹³.

The practical cases where this matters are common in UK housing. A roof with a main south-facing plane and a smaller east or west return, a roof with a dormer splitting the array, or a roof where a chimney casts shade across part of the panels for part of the day. In each case, splitting the array across two trackers keeps the unshaded group producing at full rate while the affected group does what it can.

Two trackers do not solve shade within a single string. If one panel in a group is shaded, the whole group on that tracker is affected, because they are wired in series. Module-level electronics are the answer to that problem, and power optimisers and microinverters cover the alternatives. Roof orientation and shading more generally are dealt with in roof orientation, pitch and shading.

Buying and delivery: distributor availability and restrictions

The F Series reaches UK buyers through distributor catalogues of Fox ESS solar inverters². There is no published collection or counter-service arrangement for this range, and no lead time or delivery term in the material available. Those are set by the seller and need confirming before an order is placed.

Trade purchasing in the UK often carries restrictions, and the pattern is worth understanding even though it is drawn from a different trade body. OFTEC states that registered technicians and businesses can only buy products related to their scope of registration, and that trade association members and approved training centres can only purchase technical publications¹⁹. Solar distribution does not work on identical lines, but the principle that some trade counters sell only to registered trades is common, and it is why a householder may find a product listed online but not available to buy directly.

Availability can also be regional. SolaX notes of one of its products that it may only be available in specific regions²⁰, and SuperFOIL lists one of its products as available for online purchase and in selected stores²¹. Neither statement is about Fox ESS, but both illustrate that a listing does not guarantee supply to every postcode.

Fox ESS itself maintains a UK presence. It exhibited at Solar & Storage Live 2026 at the NEC Birmingham from 22 to 24 September, on stand C14, with an afterparty on 23 September²². Trade shows are where installers see new stock and where distribution terms are discussed, and a brand with a stand at the main UK solar exhibition is a brand with a UK channel.

For a householder, the practical route is through an installer rather than a distributor. The installer buys the inverter, holds the trade account, and carries the responsibility for matching it to the array and commissioning it. Solar panel installation sets out how that process runs from survey to handover.

What a PV-only inverter means for energy independence

A PV-only inverter gives a home one thing and withholds another. It lets the roof generate, which reduces the electricity bought from a supplier during daylight hours. It does not let the home store that generation, so anything not used at the moment it is produced goes to the grid, and anything needed after dark comes back from the grid.

Fox ESS states that a PV-only system typically includes solar modules, a grid-connected inverter, a connection to the utility grid and no battery storage, and that this lowers upfront investment⁶. That is an accurate description of the trade: less spent at the start, less independence gained. The household remains dependent on the grid for every evening and every winter, and on a supplier for whatever the panels do not cover.

The dependence does not stop at the meter. A grid-connected inverter needs a live grid connection to operate, so a power cut takes the system down with it, and the question of what happens then is covered in do solar panels work in a power cut. Export payments depend on a supplier and a meter, which getting paid for solar export explains. And monitoring, if the household uses it, depends on the maker's platform and a broadband connection.

Adding storage later is possible, but not on this inverter. Fox ESS states that its high-voltage battery systems are designed to operate with compatible hybrid inverters as part of an integrated residential energy system⁴, and that supported capacity, number of battery units, installation method, depth of discharge, ingress protection and compatible inverter combinations vary by model and regional portfolio⁴. The maker also warns against mixing battery families, module types or generations unless the applicable Fox ESS documentation explicitly approves the combination⁴. A household that wants storage on the Fox ESS platform is choosing a hybrid inverter from the start, and adding battery storage to solar covers what that involves. The broader picture of what generation alone can and cannot do for a home is in solar panels and household energy independence.