Trailfinders is a travel company with a network of travel centres across the UK and Ireland. Its Cardiff branch sits at 18 Queen Street, in the pedestrianised heart of the city, where consultants plan and book trips for customers in person and over the phone.

The centre trades through the day, opening from early morning into the evening across the week. Its electricity use is the steady daytime kind you would expect of a city-centre retail unit, with lighting, workstations, screens and comms running through opening hours.

That daytime pattern is why the flat roof above the unit was a sensible place to generate some of that electricity on site rather than draw all of it from the grid.

The roof is a flat commercial rooftop above the travel centre, so the array sits on a ballasted mounting frame that holds it at a shallow tilt without drilling into the roof covering. Sixteen AIKO 475W panels are angled to the south-east to catch the sun through the working day, giving a 7.6 kWp system on a single SolarEdge inverter.

Each panel runs on its own power optimiser rather than being wired in a single chain. On a city-centre roof that detail earns its place: surrounding buildings throw shade across parts of the roof at different times of day, and per-panel optimisation means a shaded panel drops its own output without pulling the rest of the array down with it.

Over a year the array is expected to generate around 8,367 kWh and take roughly 1.62 tonnes of carbon off the building's footprint, the equivalent of about 74 trees. Because it generates across the trading day, that electricity is there to be used in the building as it is made.