Capital City Academy

System Overview

The project involved the design, supply, installation, and commissioning of a large-scale rooftop solar PV system, integrated into the client’s existing low-voltage electrical infrastructure and site-wide monitoring systems. The installation forms part of the site’s wider energy strategy, enabling renewable electricity generation while maintaining full compliance with UK grid connection and safety regulations.

Solar PV Array Installation

A total of 9,456 Hengdian Group DMEGC DM500M10RT-B60HBB photovoltaic modules were installed across the rooftop. The modules were mounted using the Kingspan PowerRail RW mounting system, specifically designed for installation on Kingspan KS1000RW roof cladding. The system was installed in accordance with manufacturer specifications and structural requirements to ensure long-term reliability while maintaining the integrity of the roof structure. To maximise performance and monitoring capabilities, 4,736 SolarEdge S1000 optimisers were installed in a 2:1 module configuration, providing module-level monitoring and improved overall system performance.

Inverter Installation

The system incorporates 27 SolarEdge SE100K three-phase inverters, which convert the DC electricity generated by the solar panels into usable AC power for the building. The inverters were installed on bespoke Unistrut support frameworks, designed and constructed specifically for the project to safely house the inverter equipment and associated low-voltage infrastructure.

DC & AC Cabling Infrastructure

A comprehensive DC and AC cabling system was installed to connect the solar array to the inverter infrastructure and main electrical distribution points.

Key elements included:

DC cabling installed within stairwells using cable ladder systems with protective lids Pemsa Metatray cable containment installed at roof level to provide UV protection and mechanical support for exposed DC cabling Custom DC combination boxes installed at roof level and at inverter locations These combination boxes allow multiple PV strings to be combined into larger DC circuits for transmission back to the inverter locations, where they are then segregated and terminated safely.

LV Infrastructure & Grid Compliance

The installation required upgrades to the site’s existing low-voltage infrastructure to accommodate the new solar generation capacity. This included the installation of five new LV panels incorporating integrated G99 protection relays, ensuring compliance with UK grid connection regulations. Existing LV panels were also upgraded by specialist contractors, including enhancements to copper busbars to safely accommodate the additional PV circuits.

Monitoring & Export Limitation

The solar PV system has been integrated with the site’s existing Argand monitoring system, which manages system performance and export limitation across the facility. The Argand system interfaces with the client’s existing fibre network infrastructure, enabling real-time monitoring and data reporting. To ensure compliance with G100 export limitation requirements, the monitoring system actively controls the amount of electricity exported to the grid. For additional safety, the Argand system is integrated with the building’s fire alarm system. In the event of a fire alarm activation, a relay signal automatically shuts down all PV inverters. Network cabling to each inverter was installed by specialist contractors to allow full remote monitoring and system management.

Firestopping & Weatherproofing All new building penetrations created during the installation were fire-stopped in accordance with regulatory requirements. Bespoke weather cowls were fabricated using matching cladding materials, ensuring the building envelope remained fully weatherproof while maintaining the appearance and integrity of the roof structure.

Commissioning & Testing

Following installation, the system underwent full inspection, testing, and commissioning in accordance with BS 7671 wiring regulations, DNO requirements, and manufacturer specifications.

Commissioning activities included:

Mechanical and electrical installation inspections DC string polarity and continuity testing Insulation resistance testing of DC circuits Verification of optimiser pairing and communication Inverter configuration and firmware validation Functional testing of G99 protection relays G100 export limitation testing Fire alarm inverter shutdown verification Monitoring system communication checks

All commissioning results and documentation were included within the final project handover pack. Health & Safety & CDM Compliance The project was delivered in full compliance with the Construction (Design and Management) Regulations 2015 (CDM 2015). A detailed Construction Phase Plan (CPP) was developed prior to works commencing, supported by comprehensive risk assessments and method statements (RAMS).

Key safety measures included:

Site inductions and controlled access procedures Work-at-height safety controls and rescue planning Temporary works assessments for bespoke frameworks Crane lifting plans and controlled lifting operations Fire safety planning and emergency procedures All operatives involved in the project were appropriately trained and competent for the tasks undertaken. Quality control inspections were carried out throughout the installation to ensure compliance with design specifications, statutory requirements, and health and safety standards.