Two panels can carry identical specifications and still look completely different on a house, because how they’re mounted matters as much as what they are. We fit two pitched-roof systems: Renusol on-roof rails and GSE in-roof trays. Here’s how we choose between them with customers.
On-roof: the all-black standard
On-roof mounting fixes rails above your existing tiles, and the panels sit proud of the roof by a few centimetres. It’s the faster, more economical route, works on almost any sound roof, and with the right hardware it looks superb. That last clause matters: we specify Renusol’s all-black rail, mid clamps, end clamps and end caps as standard, so the array reads as one black surface edge to edge. No silver glints at the margins, no bare aluminium.
On-roof also runs marginally cooler, because air circulates behind the panels, and cooler panels are fractionally more efficient. For retrofits onto a healthy roof, it’s the default answer.
In-roof: flush with the roofline
In-roof systems remove the tiles beneath the array entirely. GSE’s integration trays take their place, the panels sit inside them, and the finished array lies flush with the surrounding roof, more window than appliance. It’s the cleanest look in solar, full stop.
It shines brightest in two situations. New builds and re-roofing projects, where the tiles were coming off anyway and the trays actually save materials. And design-led homes, where the flush finish justifies the modestly higher installation cost on an existing roof.
What about flat roofs and gardens?
Different problem, different specialist. Flat roofs and ground arrays use Van der Valk’s ValkPro+ range: aerodynamic, ballasted mounting that holds the optimal angle without penetrating the roof membrane. You’ll find all three systems on our Solar PV page.
Whichever you choose
The mounting is engineered for your specific roof, wind zone and load calculations included, and installed to the same standard as everything else we fit. The finish is a choice; the standard isn’t.
This guide is general information, not advice for your specific property. Every Powergy proposal is modelled on your actual roof, usage and tariff. Figures reflect typical UK conditions at the time of writing.