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Commercial solar repair in Cardiff

Emergency inverter replacement, fault diagnosis, and rapid response for commercial solar systems across Cardiff and South Wales. Offices, warehouses, schools, retail parks, and farms. Systems from 10 kW rooftop arrays to 500 kW multi-string installations. Cardiff is our home base — the one place we offer a locally-based engineer.
from £295 · emergency call-out · fixed-price quote confirmed before work begins
  • Home base — Cardiff-based engineer, same-day to next-day on-site
  • All commercial inverter brands
  • Independent — not tied to any installer
Commercial fault in Cardiff?

Free same-day remote triage and same-day to next-day on-site across Cardiff and the Vale of Glamorgan — inverter, string, optimiser, and BMS faults, with a written report after every callout.

Report a fault

Cardiff-based engineer · O&M contract holders receive priority response

I have a GivEnergy system consisting of two batteries, two inverters and a controlling EMS (Energy Management System) which has not worked since Nov 2025. After six months I discovered Solar Tech Support, reached out to them and Ron phoned me back – how often do you get that service? Could not be more helpful – worked directly with me over the phone, outside what I would call normal working hours. Lucid explanations and we were able to discuss the issues and history using camera and email history. As this was a very rare setup, Ron was able to access an EMS expert in the field to confirm the solution. One sunny day in, I am now only paying for standing charge and a few pence for spikes in grid consumption while battery catches up with house demand.

Ian · May 2026

A superb service from Ron who went beyond the normal service received from other Tech support companies. I live abroad and was badly let down when my givenergy system failed (and the company went bankrupt) and the local supplier ran away from the problem. Ron sorted the problem and even accessed specialist coding for the inverter that would not be available for suppliers. Ron also ran a full diagnostic to insure that all was in good working order afterwards. Without Rons support and patient assistance I doubt I would ever have got the system back up and running. Well done and thankyou and you have a customer for the future.

Philip Davey · Jun 2026 Google

Ron made more sense in 20 mins than our installer has done over the last 12 months There is a jungle out there and you need someone like Ron to give a comprehensive overview and solution

David · May 2026

Ron responded very promptly regarding my GivEnergy battery issue, his knowledgeable diagnosis was spot on and resolved the issue on first attempt. Would recommend to any and all.

Simon Hill · May 2026

Ron was brilliant. He really tried to help. He spent hours trying to fix our GivEnergy AIO and ultimately it became apparent that it needed parts to fix the BMS management system. As there appears to be no replacement parts available on the market, he gave excellent advice on what options are now available to move forward. He is incredibly helpful and knowledgeable.

Mark Mayson · Jun 2026 Google

Our 3 year old GivEnergy batteries froze. They were showing 0% on the app, but they were fully charged. Some how Ron took over our inverter and remotely cured the problem. We live in King’s Lynn, he is in Leeds I believe. Very grateful.

David Lewin · Jul 2026 Google
Cardiff commercial solar

Building types we repair across Cardiff

Cardiff and South Wales saw a wave of commercial rooftop solar under FiT-era and Welsh Government schemes between 2011 and 2016. Systems on schools, offices, warehouses, and farms from that period are now reaching the age where inverter failures, isolator degradation, and monitoring breakdowns become unavoidable — and Severn-estuary coastal salt air accelerates corrosion on rooftop DC isolators and connectors. As our home base, Cardiff is where our locally-based engineer attends fastest. We cover all building types.

Schools and colleges

Cardiff has a large estate of primary and secondary schools, many fitted with 10–50 kW rooftop arrays under Welsh Government and FiT-era funding between 2012 and 2016. Common faults: original string inverters reaching end of life, DC isolator failures flagged during periodic electrical inspections, and monitoring systems that stopped reporting years ago. We coordinate access with site managers and work around term-time schedules.

Offices and city-centre buildings

Commercial offices across the city centre, Cardiff Bay, and the enterprise zone. Typical systems: 30–100 kW SolarEdge or Huawei three-phase installations on flat roofs, often with export limitation under G99. Faults we see: optimiser-level failures causing string dropouts, communication board failures on three-phase string inverters, and export relay tripping during peak generation. Facilities managers need a written fault report for landlords or building insurers.

Warehouses and logistics

Large roof areas across Cardiff Bay, Grangetown, Splott, and the industrial estates towards Newport. Systems from 100 kW up to 500 kW with multiple string inverters. The most common failure mode on these sites is a single inverter going offline while the rest of the array keeps generating — the fault often goes unnoticed for months until someone checks the monitoring or notices a higher electricity bill. We diagnose which inverter has failed, source the replacement, and recommission the string.

Farms and rural sites

Agricultural buildings across the Vale of Glamorgan and Caerphilly — barn-roof arrays and ground-mounted systems from 20 kW to several hundred kW. These rural sites are often furthest from the original installer and the first to be left without support when a company stops trading. Faults include rodent damage to DC cabling, isolator corrosion in exposed coastal locations, and inverter replacements delayed because the original installer cannot respond. We attend as an independent provider with no tie to the original installation company.

Pricing

Commercial emergency repair costs

All pricing confirmed in a fixed-price written quote before work begins. Remote triage is free for Cardiff sites. These are typical ranges — exact cost depends on inverter brand, system size, and roof access requirements.

Remote triage

Free

Same-day monitoring review, error analysis, remote resolution where possible

Emergency call-out

from £295

On-site attendance, diagnosis, written fault report · out-of-hours from £449

Inverter replacement

from £1,995

Supply, install, commission, export verification, completion report

On-site repair

from £995

Isolator, fuse, connector, string repair, monitoring hardware

Brands

Commercial inverters we replace in Cardiff

Cardiff has a broad mix of commercial inverter brands reflecting a decade of different installers and procurement cycles. We carry diagnostic experience across all of them and source replacements from multiple distributors — we are not locked to any single manufacturer.

SMA Tripower

15–60 kW three-phase string inverters. Common on schools and public buildings installed 2012–2016. Grid relay failures and communication board faults are the primary end-of-life modes.

Huawei SUN2000

30–100 kW range on newer office and industrial installations. Generally reliable but communication module failures and firmware-related export issues occur.

GivEnergy commercial

Three-phase hybrid and AC-coupled units on newer Welsh commercial and farm installs. We work on GivEnergy daily — comms, firmware, and battery-pack faults. GivEnergy support →

SolarEdge three-phase

Optimiser-based systems on offices and retail. Individual optimiser failures cause string-level generation loss. We carry P370 and P505 replacements.

Solis commercial

25–60 kW units on warehouses and schools. Earlier Solis models have shorter working lifespans and fan failures are common once past 8 years.

Fronius Symo / Eco

Legacy three-phase units on older Cardiff installations. Fronius exited the UK market — we source compatible replacements and handle the switchover.

Also: Growatt, Fox ESS, GoodWe, Sofar, Enphase commercial, ABB/FIMER, Delta, and legacy Aurora/Power-One units. All supported brands →

Coverage

Commercial coverage across Cardiff

We attend commercial sites across Cardiff, the Vale of Glamorgan, and Caerphilly. As our home base, Cardiff sites receive the fastest response and no travel surcharge.

Cardiff Bay
Cathays
Roath
Canton
Grangetown
Splott
Llanishen
Whitchurch
Llandaff
Penarth
Barry
Caerphilly
FAQ

Commercial repair in Cardiff — common questions

Cardiff is our home base, so it is the one place we can offer a locally-based engineer. Free same-day remote triage is standard for all faults. For on-site attendance, our Cardiff-based engineer can usually reach commercial sites across the city and the Vale of Glamorgan same-day to next-day for urgent faults. Many commercial faults — monitoring offline, export limitation errors, communication failures — can be diagnosed and resolved remotely without a site visit.
An emergency commercial call-out starts from £295 during business hours, and from £449 out-of-hours. That covers attendance, on-site diagnosis, and a written fault report. Commercial inverter replacement starts from £1,995, and a standard commercial on-site repair from £995. All pricing is confirmed in a fixed-price quote before work begins — no hidden labour charges.
Yes. We attend schools, college campuses, council buildings, and NHS facilities across Cardiff and the Vale of Glamorgan. We carry public liability insurance, DBS-cleared engineers are available on request, and we coordinate access with site managers and caretakers to minimise disruption. Many school and public-building systems in Cardiff were installed under Welsh Government and FiT-era schemes between 2011 and 2016, and are now reaching the age where inverter failures and wiring degradation become common.
Yes — the majority of our commercial repair work in Cardiff is on systems originally installed by other companies. Many original installers have ceased trading, moved away from maintenance, or are unable to respond to faults promptly. We are fully independent and not tied to any manufacturer or installer network. We diagnose and repair regardless of who installed the system or which brand of inverter is fitted.

Commercial solar fault in Cardiff?

Tell us what has happened — which building, system size, inverter brand, and what fault you are seeing. We triage remotely the same day and confirm next steps. Cardiff is our home base, so our locally-based engineer can be on-site fast.

  • Free same-day remote triage
  • Emergency call-out from £295 · inverter replacement from £1,995
  • Systems up to 500 kW · all brands

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