Solar Inverter and Microinverter Manufacturers in the UK

Solar panels get the attention, but it is the inverter that makes the electricity usable. Every panel on a British roof produces direct current, and a household's appliances, lighting and the grid itself run on alternating current. The inverter does that conversion, silently, every daylight hour, and when it fails the panels stop contributing no matter how well they work. Around a million households in the UK have solar panels for their home¹, with more recent counts putting the figure at around 1.65 million homes generating their own solar energy², and UK homes have 6.6GW of power installed³.

The inverter is also the part of a solar system a household thinks about least and pays for twice. Independent guidance states that inverters typically need to be replaced every 10 to 15 years⁴, while panels themselves carry warranties of 25 to 30 years from well-known manufacturers⁵. Replacing one costs around £800 depending on the size and manufacturer of the system⁶. Choosing the maker of that box therefore matters as much as choosing the panels, and this page sets out who makes the inverters and microinverters fitted in UK homes, what each product family does, and what the warranty terms really give you.

Choosing between central and panel-level inverters for your roof

A string inverter is a single box, usually mounted on a wall near the panels or near the consumer unit, and it is the most common and cheapest option because it connects solar panels in series⁹. All the panels on a string feed one input, and the inverter converts the whole string's output at once. Sungrow's own technical guidance describes the modern string inverter as a lightweight, compact design with integrated mounting hardware that streamlines installation, with efficiency often above 95%⁸.

A microinverter does the same job in miniature, one per panel, mounted at the panel itself. The clearest UK example is in plug-in solar: the InstaGen plug-in solar kit includes two 435W bifacial all-black solar panels, an 800VA microinverter and a universal mounting frame that suits gardens, balconies and walls, with a manually adjustable tilt angle¹⁰. Because each panel converts independently, a microinverter setup avoids the string inverter's weakness, where one shaded or faulty panel drags down the output of every panel wired after it.

The practical differences follow from that layout. A string inverter is one component to buy, mount and eventually replace, which is why it is the cheaper and more common route for a straightforward, unshaded roof⁹. Microinverters spread the conversion across the roof, which suits awkward layouts, partial shading and the small self-installed arrays now sold for balconies and gardens¹⁰. The trade-off is that a string inverter is a single point of failure: when it stops, the whole array stops. Microinverters fail one panel at a time, but there are more of them to fail over the system's life. Neither type is a better buy in the abstract; the roof decides.

Brands UK homes typically encounter

Solar panels are the most common domestic renewable energy source in the UK¹¹, with over 1.3 million homes generating electricity from them¹², and the inverter makers behind those installations are a recognisable group. The four covered in detail on this page, SolaX, Fronius, Sungrow and Solplanet, sit alongside a wider field of brands whose UK ranges are covered on their own pages: SolarEdge inverters and power optimisers, Enphase microinverters, GoodWe solar inverters, Growatt, Fox ESS, Sunsynk, SMA Sunny Boy, Huawei, Solis and APsystems microinverters. The full list of brands, warranties and certification sits on the manufacturers pillar page.

The market is also widening at the small end. Plug-in solar panels, the balcony and garden kits built around microinverters, are now part of the mainstream: Amazon and Lidl have been named as retailers working with government to roll them out in the UK¹³, and one in eight households, 13%, plan to get plug-in solar panels within the next five years¹⁴. The government has said the panels will be available in shops within months and save people money on their bills¹⁵, and reporting ahead of the law change suggested availability at retailers such as Lidl and Sainsbury's¹⁶.

For a household comparing quotes, the practical point is that the inverter brand is usually the installer's choice, not yours, but it is the component with the shortest life and the most active warranty. Asking which inverter family a quote uses, string, hybrid or microinverter, and what the maker's warranty and monitoring platform offer, is a fair question to put to any installer.

SolaX: string and hybrid inverters, batteries and EV charging from one maker

SolaX Power is the clearest UK example of a maker that sells a whole home energy pathway rather than a single box. Its official UK site presents residential storage inverters, batteries, EV charging, and integrated home energy pathways¹⁷. That breadth matters to a household because the inverter is the component that decides what else the system can do later: a hybrid inverter can charge a battery, a plain string inverter cannot, and a maker that supplies both plus the battery and the charger makes the pieces speak the same monitoring language.

SolaX's own guidance separates its ranges by purpose. Its string inverter is listed as suited to a simple PV array, while its hybrid inverter is listed for solar plus battery¹⁷. That is the dividing line for most homes: a household with no battery and no plans for one is served by the string inverter, while a household expecting to add storage starts with the hybrid unit rather than buying a second inverter later. The same guidance sits behind the maker's discussion of premium versus mid-range inverters for UK homeowners¹⁷.

Availability is through the trade rather than direct: SolaX battery systems reach UK homes via UK installers¹⁸. That is normal for this market, and it shapes the warranty position, because registration and claims usually run through the installing company in the first instance. If a SolaX warranty registration fails or is never completed, the maker's cover can be at risk, which is a common and avoidable problem with inverter warranties generally.

For the independence picture, SolaX illustrates a trade-off worth naming. Buying the inverter, battery and charger from one maker simplifies monitoring and support, but it deepens dependence on that one company's firmware updates, app and spare parts operation for the whole system's life. A household that mixes brands keeps more options open at the cost of more apps and more support lines to deal with.

Fronius Symo: a transformerless three-phase unit for indoor or outdoor mounting

Fronius is an Austrian maker whose Symo range is a fixture of larger domestic and small commercial installations in the UK. The Symo is a transformerless three-phase inverter¹⁹, and the range spans models including the 3.0-3-M, the 3.0-3-S and the 6.0-3-M. Three-phase output suits homes with a three-phase supply and larger arrays, and the transformerless design is the modern standard: fewer losses, less weight, no bulky isolation transformer inside.

The specification the maker publishes is consistent across the range, and it answers the question households ask most often about siting. Every one of these models is listed for installation indoors and outdoors¹⁹, with regulated air cooling¹⁹ and protection class 1¹⁹. The physical footprint is identical across the models listed: 432,5 mm wide, 642,5 mm high and 205,5 mm deep¹⁹, roughly the size of a small wall-mounted cupboard unit.

Outdoor mounting is the common choice for these units, on an outside wall close to the array, and the maker's own datasheets permit it¹⁹. What the datasheet permits and what an installation allows are different things: siting still has to follow the manufacturer's instructions and UK wiring rules, and the inverter still needs its clearances for that regulated air cooling to work. A household's practical interest in the Symo range is that it is built for the larger end of domestic solar, where a three-phase supply and a bigger array make the extra capacity worthwhile. Fronius also runs a returns process for faulty parts, covered separately on this site.

Sungrow: string inverters, optimisers and remote monitoring

Sungrow is one of the largest inverter makers in the world and a common name on UK installation quotes, with its home battery and inverter range covered on its own page. Its published technical guidance on string inverters sets out what the modern generation of its equipment does, and it reads as a description of what has changed in the whole string inverter market.

Three points from that guidance matter to a household. First, efficiency: solar string inverter efficiency is often above 95%⁸, which means the conversion loss between panel and socket is small but not zero, and it is worth remembering when comparing quotes. Second, installation: a lightweight, compact design and integrated mounting hardware streamline installation⁸, which shows up in labour time and therefore in the installed price. Third, and most significant for ownership, advanced inverters feature remote monitoring and diagnostics⁸.

That last point cuts both ways for energy independence. Remote monitoring means a fault can be spotted and often diagnosed before the household notices, and diagnostics can distinguish a firmware problem from a hardware failure without a site visit. But it also means the inverter talks to the maker's cloud, and the household's view of its own generation runs through the maker's app. If the maker withdraws app support for an older model, the hardware keeps working but the household's visibility into it can degrade. That is a general risk with connected inverters, not a Sungrow-specific one, and it is covered in detail on our page about firmware updates, app support and product lifespan.

Sungrow's product family also includes power optimisers, the panel-level electronics that pair with a string inverter to recover output from partially shaded arrays. The combination sits between a plain string system and a full microinverter setup: one central inverter, but with conditioning at each panel. For a household weighing it, the question is the same one that opens this page, namely whether the roof's shading justifies electronics at every panel, and the answer belongs to the site survey rather than the brand brochure.

Solplanet cover: 5 years standard, 10 with extension, plus the claims process

Solplanet is a maker whose UK presence is growing, and its warranty terms are published in enough detail to serve here as a worked example of how inverter warranties actually operate. The headline terms are straightforward: Solplanet offers end-users a standard warranty of up to 5 years, and the warranty can also be extended for up to 10 years²³. The extended cover is the figure to check on any quote, because the difference between 5 and 10 years spans a large share of an inverter's working life.

Two finer points in the terms deserve attention. First, the maker's warranty does not affect the legal warranty provided by any wholesaler or retailer²³, which means your rights against the seller of the equipment are separate from and additional to the maker's cover. Second, the warranty start date is not simply your installation date: Solplanet's rule is the earlier of the date of first installation, or six months after the initial shipment date²⁴. Equipment that sat in a distributor's warehouse can therefore have a warranty already running before it reached your wall.

The claims process is set out by the maker. If problems arise during the warranty period, the customer contacts Solplanet's customer support department or uses the online claim form²⁵. The maker also states its backup position plainly:

That commitment matters because inverter failures remove generation immediately, and a warranty that requires the failed unit to be collected, repaired and returned leaves a household without solar for weeks. Solplanet also provides an online tool to validate the current warranty status of an inverter, connection or monitoring device²⁵, which is the first stop before paying anyone for a repair. As a general benchmark, most inverters carry warranties of five years as a minimum, often extendable by up to 15 years⁷, so Solplanet's 10-year extended ceiling sits within the market's range rather than above it. The wider rules on keeping a maker's warranty valid, including registration, are covered on our warranty registration page.

Price and supply: expect to pay about £800 for a replacement

The inverter is the solar system's recurring cost, and the independent figures on replacement are consistent. Energy Saving Trust states that inverters typically need to be replaced every 10 to 15 years⁴, and the Centre for Sustainable Energy's guide notes an inverter may need to be replaced after around 10 years²⁶. On price, the same guidance puts replacement at about £500 to £1,000²⁶, while Energy Saving Trust gives a figure of around £800⁴, and its solar power facts page likewise puts replacement at around £800 depending on the size and manufacturer of the system⁶.

Those figures are for like-for-like replacement of a failed unit, not for a new installation, and they are the numbers to plan for across a panel's 25 to 30 year warranty life⁵. Which? made the same point bluntly in its survey of common solar panel problems: panels can have warranties of up to 20 or 25 years, but inverters are not expected to last as long²⁷. A household budgeting honestly for solar can expect to buy the inverter twice over the panels' life.

For new equipment, prices are installer-quoted, and the maker and distributor list prices that appear online for specific models vary between listings, so no reliable single figure can be given here. What the independent figures do support is the shape of the market: string inverters are the cheapest option⁹, microinverters add cost per panel, and hybrid inverters cost more than plain string units because they add battery charging capability.

One related cost is worth naming because it is often confused with the inverter: a solar diverter, which sends surplus generation to the immersion heater instead of exporting it, costs £250 to £500 to buy, or £600 to £800 with installation²⁶. It is a separate device with a separate life. The availability picture for the small end of the market is changing quickly, with plug-in kits now on retail sale¹⁵, but for full rooftop systems the inverter still reaches your home through an installer, and the quote, not a shelf price, is the real cost.

How inverter ownership affects your self-sufficiency

The inverter is where a household's solar independence is both created and capped. It is the component that turns generation into usable home electricity, and with a battery behind it the numbers change sharply: Uswitch data from June 2026 put the self-consumption rate of British households with solar and a 10kWh battery at 70%²⁸. That is the share of what the roof makes that the home actually uses, and it is the closest thing to a headline figure for household energy sovereignty. At the national scale, the same shift is described as reducing dependence on fossil fuel imports²⁹.

But the dependence that remains is real and worth stating plainly. The inverter does not free a household from the grid; it changes the terms of the relationship. Surplus still flows out, shortfall still flows in, and a grid connection application for generation and storage is part of the process for many systems³⁰. The inverter itself is an imported product, supported by a manufacturer's firmware, cloud monitoring and app⁸, and when that support ends the hardware keeps converting but the household's control and visibility can fade. That is why the maker's support life matters as much as its warranty years, a subject covered on our manufacturers and household energy independence page.

The replacement cycle is the other limit. Panels outlast inverters by a wide margin, 25 to 30 year panel warranties against 10 to 15 year inverter lives⁵, and each replacement is a fresh decision about brand, warranty and whether to add battery capability. A household that registers its warranty, keeps its installation paperwork and checks the maker's online warranty tool before paying for repairs²⁵ protects the value it has already bought. The inverter will not make a home independent on its own, but it decides how much of the roof's work the home keeps, and choosing its maker with the same care as the panels is what makes the independence last.