Alectrona
How we workA commercial solar system is an engineering problem with a return attached, and we solve it the same way every time. Model the load before anyone visits, fly the roof properly, design to named standards, build under a contract that holds us to them, then look after the asset for the years it has to earn.
Surveytheroof.Modeltheload.Designtostandard.
Thenlookafteritfortwenty-fiveyears.
This is the whole story of how a commercial project runs with us. Every stage below has its own page carrying the detail, but you should be able to read this one and know what you would be buying into before you speak to anybody here.
The sequence does not change between jobs, because each part of it exists to stop a specific thing going wrong later. A free remote survey establishes whether the project is worth anyone’s time. An on-site 3D drone survey replaces the satellite guess with measured geometry. A PV*SOL model run against your half-hourly consumption sets the size. The design is drawn to BS 7671 and the connection applied for under G99. The build runs under CDM 2015 with a named Principal Contractor and a JCT or NEC contract. Commissioning follows IEC 62446-1, handover gives you the records, and twelve months of defects rectification under an Insurance-Backed Guarantee sits behind the work. Then maintenance carries the asset through its working life.
Above 50 kWp the domestic certification scheme does not apply, so the assurance has to come from the engineering itself: named standards, an enforceable contract, and a sign-off discipline where the person who did the work is not the person who passes it. That is why the design, rather than the panel brand, is the part of a commercial proposal worth reading closely.
The last chapter is the one most installers leave out. We take on systems somebody else built, and we audit systems we are not selling. That is why a director with a quietly underperforming array, or an installer who has stopped answering the phone, has somewhere to go.
The flow
A free desktop model from your address and half-hourly data, then an insured in-house pilot flies the roof in three dimensions.
Before you commit
Generation modelled against your real load, the system sized to the overlap, and drawings produced to BS 7671.
From the survey
Applied for early, because the export limit your Distribution Network Operator will grant shapes both the array and the programme.
Paced by the DNO
Built to a construction phase plan with a named Principal Contractor, under a JCT or NEC contract.
Days on site
Tested to IEC 62446-1, handed over as a documented file, covered for twelve months of defects, then maintained for the asset’s life.
Ongoing
Most enquiries do not need a site visit to answer the first question, which is whether the roof and the load make a project worth pursuing. So we answer that one for nothing. Send the site address and your half-hourly electricity consumption data, and an engineer models it in PV*SOL from aerial imagery and your real usage.
What comes back is a branded report with your own figures in it: the indicative system size the roof looks able to carry, the generation it should produce across a year, how much of that your business would use on site rather than export, and the financial shape that follows. There is no charge, no visit, no contract and no term at the end of it. If the model says the project does not stack up, that is a legitimate answer, and the report is still yours to circulate internally.
It is desktop work, so it is close rather than final. Roof condition, structural capacity, the plant already up there and the grid connection can all move the answer, and only the on-site survey settles them. What it does is stop you spending management time on a project the numbers were never going to support.
Desktop modelling first, so nobody spends a site visit on a project that was never going to work.
Once the desktop case holds, the real survey happens on your roof. Our own pilot, holding an A2 Certificate of Competency and a General VLOS Certificate and fully insured, flies the site and captures it as a measured three-dimensional model. The output is survey data rather than a photograph: real roof area, real orientations and pitches, the position of every rooflight, vent, plant unit and cable route, and the way shading moves across the roof through the year.
This is the step that decides whether a price holds. A layout dragged across a satellite image cannot see that a third of the usable area is taken by air handling units, that the roof sheets run the wrong way for the rail spacing, or that a neighbouring unit shades the southern rows all winter. Those things surface once the scaffold is up and the variation is expensive.
The model then becomes the thing we design in. Panel positions, walkways, edge exclusion zones, inverter and isolator locations and cable runs are drawn onto measured geometry, so what you approve on screen is what gets built. It also feeds the shading analysis inside PV*SOL, which is where the generation figure in your proposal comes from.
Measured geometry, not a satellite outline, is what a fixed price rests on.
A commercial array is sized to consumption rather than to roof area. The value sits in the power you use on site instead of the power you export, so the shape of your demand matters more than how much roof you happen to have. We take your half-hourly data from the meter, run it against the modelled generation profile in PV*SOL, and look at where the two curves overlap.
That overlap is the number the business case rests on. It tells us how much of the generation the site would absorb, what spills to export at a far lower value, and whether battery storage earns its place by shifting the surplus into the evening. It also tells us at what point a bigger array stops paying, which is a conversation an equipment salesman has no reason to start.
Only then is the system specified and priced. You receive a designed system for your roof with a fixed price against it, not a rate per kilowatt-peak applied to a rough area. We do not publish a from-price, because one exists to be revised the moment somebody finally looks at the building.
The proposal leads with the capital purchase, because buying the asset outright keeps every saving and every pound of tax relief with you. Lease-purchase and power purchase agreements are explained properly on the finance pages, but they are alternatives to the capex case rather than the way we open.
Above 50 kWp there is no consumer certification scheme standing behind the work, and pretending otherwise would be dishonest. What protects your capital is a design that meets named standards, a contract that binds both parties to them, and a sign-off discipline that does not let the installer mark his own homework.
Almost everything the system earns across its design life is decided on paper before a single fixing goes onto the roof: string configuration and inverter sizing, cable routes and volt drop, isolation and labelling, earthing and surge protection, fire-service access and walkways, structural loading against wind and snow, and the export limit the network will grant. Those are the drawings a funder or an incoming buyer will ask to see in ten years.
Our Qualifying Supervisor, a fully AM2-trained electrician, reviews the install file on every job before commissioning is signed off: photographs, test certificates, the torque-check log and the commissioning data. The engineer who did the work never signs off his own work.
That page also carries two worked examples of the method, a flat-roof distribution centre on a daytime logistics load and a stadium stand roof on an event-driven one, alongside the full list of what you receive before contract and at handover. Neither example is a delivered project: Alectrona publishes no completed installs and no client references, so both are kept qualitative with no generation, saving or payback figure attached.
The UK wiring regulations, including the sections written for photovoltaic supplies. The design is drawn to them and the handover certificate cites them.
The commissioning and documentation standard for grid-connected PV. It defines both the tests the system must pass and the records it is handed over with.
The connection agreement with your Distribution Network Operator, applied for early because it sets both the export limit and the programme everything else hangs off.
Construction duties, with the roles named in writing. On most of our projects Alectrona holds the Principal Contractor position.
MCS is the domestic scheme and does not extend to systems of this scale, so it is not offered here as a credential.
A quarter of a century of generation is won or lost after the invoice is paid.
On site the work runs to the construction phase plan. Access, edge protection, lifting, roof loading and the live electrical interfaces with your building are planned before anyone climbs a ladder, and your facilities team gets a programme saying which areas are affected and when. Most commercial roofs stay in use while we work, and the plan is written on that assumption.
Mechanical installation comes first: the mounting system set out from the surveyed model, ballast or fixings specified against the structural calculation, then modules, DC cabling and containment. Electrical work follows through inverters, AC cabling, protection, isolation and metering. Where the roof needs penetrations, they are weathered to the roof manufacturer’s own detail, so the covering warranty survives.
Commissioning is a test regime rather than a switch. Following IEC 62446-1 we run insulation resistance, polarity and continuity checks, open-circuit voltage and operating current on every string, earth continuity, protection and isolation tests, and the export limitation check the connection depends on. Results are recorded string by string, so a reading taken five years from now has something honest to compare against.
Handover is a file rather than a handshake. You receive the as-built drawings, the electrical installation certificate, the commissioning and test records, the O&M manual, equipment datasheets and warranties, the structural and wind-loading calculations, the DNO paperwork and the monitoring credentials. That set is what an incoming buyer, insurer or funder will ask for, and assembling it after the fact is close to impossible.
For the first twelve months there is a defects-rectification period: anything that proves to be a defect in our workmanship, or in the equipment we supplied, is put right by us. An Insurance-Backed Guarantee sits behind it, so the cover does not depend on the installer still trading. Equipment warranties run for their own terms on top, and we hold the paperwork that lets you claim.
Switch-on is the start of the part that matters. A commercial array is expected to generate for around twenty-five years, on a roof nobody walks across, wired into a building whose use will change several times. Left alone it degrades quietly. Modules soil, connectors work loose, a string drops offline and the inverter carries on reporting a plausible average, a monitoring feed dies and nobody notices for a year. None of that trips an alarm inside the building. It shows up as a bill that drifts back up.
Operations and maintenance is the work that stops the drift. Planned inspection covers the mechanical condition of the mounting and fixings, thermal imaging and visual inspection of modules and connections, inverter servicing, electrical testing, and cleaning where soiling is genuinely costing generation rather than as an annual ritual. Alongside it, continuous monitoring compares what the system produced against what the model says it should have produced in the weather it actually had. That turns a vague sense that the bills look high into a named string on a named inverter.
What we will not do is put a response-time promise on a web page. Maintenance scope and attendance are written into your contract in terms both sides can hold each other to, rather than advertised as a number nobody has audited.
Planned inspection and monitoring, so a fault is found before a quarter’s generation is.
Most solar companies are only interested in a roof with nothing on it yet. That leaves a large population of commercial arrays with nobody accountable for them: installed in one of the boom years, signed off by a company that has since folded or been sold on, and running unattended since. If you have inherited one, you are the normal case rather than an awkward one.
We work on them for the same reason we design new systems properly: the engineering does not care who put it up. Three services cover the ground, and which one you need depends on how much you already know.
All three are brand-agnostic, and the diagnostics behind them run through the group’s separate technical arm, Solar Tech Support, whose entire job is fault-finding on other people’s installations. When the answer is that the system is basically healthy, that is what the report says.
For a live system you already operate, where the question is whether something is broken or it was simply a poor quarter for sun. We model your own site, compare actual generation against what the weather should have produced, and put a cause and a priority against whatever is missing.
A technical review written for the owner, buyer or funder rather than for an installer, by an engineer with no stake in the answer. It covers design and as-built review, performance against what the system was meant to do, and safety and compliance.
When the firm that built the array has folded, been sold on or stopped answering the phone, we adopt it. The system is diagnosed first, what is wrong is put right, and the asset carries forward under a written maintenance contract with an accountable party behind it again.
Whichever route applies, the report is the deliverable. Taking the maintenance on afterwards is your decision, not a condition of it.
Strip out the stages and the standards and what is left is a few things we do not trade away.
The Qualifying Supervisor reviewing an install file did not carry out the installation. It is the cheapest quality control there is, and the first thing to disappear when a company gets busy.
Roof geometry comes from a flown survey and generation comes from a model of your own half-hourly load. Every figure in a proposal traces back to one of those two, or it does not go in.
Twelve months of defects rectification, an Insurance-Backed Guarantee behind it, maintenance under contract, and a willingness to take on the work somebody else walked away from.
Last updated August 2026
A free remote survey. Send the site address and your half-hourly consumption data and an engineer models it in PV*SOL, then returns a report with your own indicative system size, annual generation, on-site usage and financial picture. No charge, no obligation. If it holds up, the on-site 3D drone survey turns that model into a design and a fixed price.
Our Qualifying Supervisor, a fully AM2-trained electrician, reviews the install file on every job before commissioning sign-off: the photographs, the test certificates, the torque-check log and the commissioning data. We are an engineering company first, so the person who carried out the work never signs themselves off.
On most of our projects Alectrona holds it under CDM 2015, with the Principal Designer and client duties named in writing at the start. That means a construction phase plan, method statements, site inductions and one accountable party while your building carries on being used. Where a Principal Contractor is already appointed across a wider programme, we work under them to the same plan.
Handover gives you the as-built drawings, certificates, commissioning records, manuals, warranties and monitoring credentials as one file. A twelve-month defects-rectification period follows, backed by an Insurance-Backed Guarantee. After that the asset is carried by planned maintenance and monitoring for its working life.
Yes, and it is a large part of what we do. If the savings have quietly slipped, a performance audit separates a real fault from a poor quarter of weather. If you are buying or funding the building, an independent audit reports to you rather than to an installer. If the original company has gone, a system takeover puts an accountable party behind the asset again.
Yes, by definition. MCS is the domestic certification scheme and does not apply to commercial systems over 50 kWp. The assurance comes from the engineering stack instead: design to BS 7671, commissioning to IEC 62446-1, a G99 grid connection, CDM 2015 construction duties and a JCT or NEC contract, with independent sign-off.
There is no list price. The figure comes from the on-site survey and a PV*SOL model run against your half-hourly load, because roof type, plant, shading and the grid connection all move it. We fly the roof, model your real consumption, then return a designed system with a fixed price you can take to the board. The commercial solar cost guide explains what drives it, and finance covers how it can be paid for.
The survey reaches you quickly from our Yorkshire base, so the early stages move fast. After that the programme is paced by the G99 connection to your DNO rather than by travel or panel supply. Your proposal comes with a dated programme built around that connection. The installation timeline guide walks through each stage.
Send the site address and your half-hourly data and the first model costs you nothing. If it holds up, we fly the roof, design the system and come back with a fixed price you can take to the board.