What we fit
The products behind our systems
A handful of manufacturers earn a place in our systems: Fox ESS for commercial battery storage, Sigenergy for integrated storage with EV charging built in, SMA for the inverters on bigger roofs, and the Tesla Powerwall for homes and smaller sites. This page is the map; each brand has its own page with the datasheet numbers, the warranty small print and the honest caveats.
Specified per project · Confirmed per quote · Based in County Durham
In one paragraph: we are a contractor, not a franchise — no manufacturer tells us what to sell, so the shortlist below is ours, picked deliberately from the middle of the market. Middle of the road on price does not mean middling engineering; it means kit whose numbers survive our own modelling and whose warranties are published documents we have actually read — and quoted, clause by clause, on each brand's page. What we specify for your building depends on your roof, your load profile and your plans, and it is confirmed in writing on your quote, not assumed from a brochure.
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Manufacturer image · fox-ess.com Battery storage
Fox ESS — the battery brand we fit most
Our value-per-kilowatt-hour pick for commercial battery storage: H3 Pro three-phase hybrid inverters from 15 to 30 kW, paired with modular ECS battery stacks of up to 29.03 kWh each — and a UK-published warranty that runs to 12 years on the batteries when registered and monitored properly, which we handle at commissioning. The brand page covers the specs, the cold-weather honesty and the warranty arithmetic nobody else prints.
Read the brand page →
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Manufacturer image · sigenergy.com Integrated storage + EV
Sigenergy SigenStor — storage and EV charging in one stack
The most modern kit we install: inverter, batteries and an optional DC EV-charging module stacking into a single IP66 tower — up to 48.3 kWh of storage per tower — with the energy management built in. We will also tell you, unprompted, that Sigenergy was founded in 2022, and exactly why we specify it anyway. If EV charging is in your plans, read this one first.
Read the brand page →
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Manufacturer image · sma.de Inverters
SMA — the German workhorse on the roof
Building inverters since 1981, and the safest long-game bet in our catalogue: Sunny Tripower X (12–25 kW) for most farm and industrial roofs, and the free-standing 50 kW CORE1 for the big sheds our commercial solar work is built on. The brand page includes the straight talk the brochures skip — including the fact that these are pure string inverters, and what that means for adding storage.
Read the brand page →
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Battery storage
Tesla Powerwall — the all-in-one home battery
The battery everyone knows, fitted by Tesla-approved installers. The Powerwall 3 puts the solar inverter, the battery and the controller in one wall-mounted unit — 13.5 kWh of storage, expandable to 54 kWh, with seamless backup. It is a home and light-commercial battery; for big industrial loads we scale Fox ESS or Sigenergy instead, and the brand page says exactly where that line sits.
Read the brand page →
Also supplied: SolaX inverters — specified per project and confirmed in writing on your quote.
And the panels?
Deliberately absent from the brand list above — not because they matter less, but because we will not name a flagship until we can stand behind the choice in print. What we fit is tier-1 monocrystalline panels with 25-to-30-year performance warranties, selected per project on the same test as everything else: datasheet evidence, published warranty terms, and suitability for the roof in question. The full panels story — yields, roof types, and how panel wattage becomes system size — lives on our commercial solar PV page, and the specific make and model for your building is named on your quote, where it belongs.
Why these three brands and not the ones we've seen advertised?
Because we pick as engineers spending your capital, not as a marketing channel. The shortlist balances three risks a business actually carries: value for money today (Fox ESS), integration and future-proofing (Sigenergy), and manufacturer longevity across the system’s life (SMA, 45 years old). Ask us about any brand you have been quoted elsewhere and we will give you the same style of answer about it — datasheet and warranty first, adjectives second.
Can we mix brands in one system?
Yes — and on larger sites we often should. The commonest commercial architecture pairs SMA string inverters on the solar side with an AC-coupled Fox ESS or SigenStor battery system alongside, each doing the job it is best at. The design rules for that live with us rather than with any one manufacturer — which is precisely the point of being the contractor rather than the franchise.
Want the right kit, not the loudest brand?
Tell us about the building and how it uses power, and the quote will name every component — panel, inverter, battery, charger — with the reasoning attached. If a cheaper box does the same job, it will say that too. Call 07720 802405 or use the form.
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Commercial solar, battery, EV or any electrical work — no pressure.