Alectrona
Case study · Warehousing & logisticsA large single-span warehouse roof, a daytime operation that runs hard while the sun is up, and a grid connection that would not welcome a big new exporter. The method is a self-consumption-first, export-limited design built from half-hourly load data and an in-house drone survey, so most of what the roof generates is used on site rather than sent to the network.
These are representative example reviews, not yet-collected customer feedback. They are written to illustrate the kind of feedback Alectrona aims to earn and are shown as design placeholders while we gather and verify reviews from our first commercial clients. Alectrona is the commercial solar trading brand of RVTC LTD.
What set Alectrona apart was the documented design pack. We had quotes from three installers, but only Alectrona handed us a full set of drawings, a single-line diagram and a design referencing BS 7671 and the G99 connection process. The whole thing read like an engineering submission rather than a sales brochure. Our M&E consultant reviewed it and signed it off without a single query. That gave the board the confidence to release the capital.
Other firms priced our roof off a satellite image and a desktop guess. Alectrona flew an in-house drone survey, fully insured and flown by a qualified commercial drone pilot, and built a 3D model of the actual roof. It picked up plant, vents and a parapet line that a flat aerial photo had completely missed, which changed the panel layout. I would rather find that out at design stage than on the day the scaffold goes up. The accuracy of that survey is the reason I trusted everything that followed.
As a finance director I was wary of being oversold a system bigger than we could use. Alectrona modelled the array against our actual half-hourly consumption data rather than an annual total, so it is sized to what we genuinely draw on site during the day. They were honest that exporting surplus is worth far less than self-consumption, and built the design around that. The capital case stacked up because the engineering was honest, not because the numbers were inflated.
We were undecided between buying outright, leasing and a PPA. Alectrona laid out all three side by side with the pros and cons of each against our balance sheet, instead of pushing the one that pays them best. They were clear about where a PPA makes sense and where capex wins, and pointed us at our own accountant for the tax treatment. The survey and design took a little longer than I expected, but the thoroughness was worth the wait. Genuinely consultative.
The install crew were tidy and well run, and worked to a clear CDM 2015 plan with a proper site induction and RAMS. What impressed me most was the handover. We received a full commissioning pack with the IEC 62446-1 test results, certification, O&M documentation and an as-built record for our maintenance team. As the people who have to live with this asset for the next twenty years, having that paperwork in order matters enormously. Nothing was left loose.
I expected the usual hard sell and got the opposite. After surveying our site Alectrona told us one roof section was not worth covering because of shading, and that a smaller, well-sited array was the better investment than filling every square metre. There was no commission-driven upselling and no pressure. For a six-figure capital project, that straight talk is exactly what you want from the people advising you. We will be using them again on our second site.
For transparencyThis is a representative example of the team's work on large flat-roof logistics arrays, written to show the engineering method rather than to report a single completed job. The technical approach, standards and survey method described are exactly how the team designs and builds a system of this kind; the building, load profile and connection position are anonymised and kept qualitative. A named client and their real project will replace it once written sign-off to publish is in place.
The site is a large distribution centre on a single-span flat roof, with a load that is firmly a daytime one. Forklift and materials-handling charging, conveyor and sortation plant, lighting and the building's own services all draw hardest across the working shift, which is the same window the roof generates in. On paper that is an ideal match for solar, but an operation like this typically carries a heavy grid-import bill on a contract due for renewal, and the finance question to answer is a capital case built on the site's real consumption, not a per-kWp rule of thumb.
Two constraints shape the work from the start. A roof of this kind is large but often lightly loaded structurally, so any mounting system has to stay within what the deck and frame can safely carry. And where the local network has limited appetite for a large new exporter, an unconstrained full-export connection risks a slow, expensive path through the distribution network operator's assessment. The brief is to capture as much of the daytime load as the roof can cover while keeping the connection straightforward and the programme moving.
The starting point is the building's half-hourly meter data. Modelling generation against the site's actual half-hourly consumption in PV*SOL is what tells you how much of each generated unit is used on site rather than exported, and on a daytime logistics operation that self-consumption share is high. The system is sized to the load this way, so the array matches the shift pattern rather than overshooting into low-value export.
The roof itself is captured by an in-house drone survey, flown by an A2 CofC and GVC-qualified pilot, to build a 3D model of the single span. That model fixes the usable area, the set-backs for firefighter access, the plant and penetrations to route around, and the structural picture that governs the mounting choice. With self-consumption high, an export-limited G99 design is the natural fit: the connection is constrained so the system asks little or nothing of the network on the export side, which can avoid triggering reinforcement and shorten the path to a connection. The design is developed to BS 7671, with commissioning to IEC 62446-1, and the works are run under CDM 2015 with the principal designer and principal contractor duties appointed in writing.
The result is a large rooftop array engineered to a daytime logistics load, where most of the energy the roof produces is consumed on site and offsets an imported unit directly, which is the most valuable place for it to go. An export-limited connection keeps the grid side simple and the programme on a settled basis rather than waiting on the network. Because the system is sized to the half-hourly load, the capital case rests on the building's own consumption rather than a generic headline figure.
At handover the operator receives the full document pack: the BS 7671 electrical certification, the IEC 62446-1 commissioning data, the G99 connection paperwork and the as-built drawings, with the install report reviewed and signed off by the Qualifying Supervisor, a fully AM2-trained electrician, before the system is energised. A defined defects-rectification period and ongoing operations and maintenance follow. Any saving or payback figure for a real site comes from that site's survey and PV*SOL model rather than a quoted number, and is indicative general information, not financial or tax advice.
Because a daytime logistics operation self-consumes most of what the roof generates, so exported units would only ever be a small, low-value tail. An export-limited G99 design caps how much the system can send back, which means it asks little or nothing of the network on the export side. That can sidestep the capacity assessment that drives reinforcement and shorten the path to a connection, while the economics already favour using the power on site.
From the building's half-hourly meter data, modelled against generation in PV*SOL, alongside an in-house drone survey that builds a 3D model of the roof. Together those tell us how much of each generated unit would be used on site and what the roof can safely carry, so the array is sized to the actual daytime load rather than to a per-kWp rule of thumb.
Not yet. This is a representative example of how the team designs a large flat-roof logistics array, written to show the engineering method. The technical approach, standards and survey process are exactly as described; the building and its figures are anonymised and kept qualitative until a named client gives written sign-off to publish their project in its place.
We model your half-hourly load against a system sized from an on-site drone survey, so the figure you get is yours, not a from-price. The same engineering discipline, on your roof.