Solar PV Installation on new flats development in Croydon, London (10.44kWp)

This new build five storey block provides accommodation in twenty-one modern apartments. The building has two flat roofs at different levels which can accommodate the installation of Solar PV panels. As a result of extensive SAP energy saving calculations the design team decided to install Solar PV panels on both the high and low roof areas.

The higher roof area presented problems as the timber frame construction was unsuitable for a supporting structure using ballast slabs, this was resolved by the use of tubular up-stand supports which could be weathered into the roof construction. These support the angle brackets to which the solar panels are fixed. The lower roof area is covered in concrete slabs and the angle frames to support the solar panels could be fixed directly to the slabs.


The design of this system was complex due to the limited space available for installation and the fact that the array of panels on the upper roof face south whilst those on the lower roof face east. This required great care in the panel layout and careful design of the wiring as multiple strings with multiple inverters to maximise the power output whilst keeping the overall output currents within the G83 grid connection guidelines to avoid additional cost.

  • Solar Panels – 58 No. BP 180Wp (46 No. on Main roof and 12 No. On lower roof)
  • Inverter Type – 3 No. Stecagrid inverter
  • Monitoring – by meter at low level
  • System output – 10.44 kWp
  • Annual output – 8027 Kwh PA (estimated)