Rooftop Solar for a Newport Secondary School: Ysgol Gyfun Gwent Is Coed

Ysgol Gyfun Gwent Is Coed sits on Duffryn Way, on the western edge of Newport near the Gwent Levels. It is the local Welsh-medium secondary, teaching pupils from across the city and the surrounding villages.

A secondary school of this scale is a busy building for most of the day. In term time it runs lit classrooms, ICT rooms, science labs, a kitchen serving hundreds of lunches and large sports and hall spaces, all drawing power from early morning through to the end of the day. Out of term the load drops but never fully stops, with cleaning, admin and holiday activity keeping parts of the site in use.

The school also has a large flat roof. That broad, uninterrupted expanse gave enough room to lay out a system big enough to make a real dent in a school-sized electricity bill, with the panels tilted on frames to face the sun rather than lying flat.

The 240 panels sit across one large roof, but they are not all angled the same way. Some face south east and some north west, and rather than run everything as one long string, the panels are wired into separate groups by orientation. That gives a 104.8 kWp system on two SolarEdge inverters, one carrying most of the array and a smaller one taking the rest.

Every panel has its own optimiser. On a spread-out roof like this that matters: as the sun moves across the site through the day, one group of panels is usually doing better than another, and per-panel optimisation lets each panel give what it can at any moment without the shaded or weaker sections holding back the rest.

Across a year the arrays are expected to produce around 95,450 kWh and take roughly 18.46 tonnes of carbon off the school's footprint, about the same as 848 trees. Most of a school's electricity gets used between the start and end of the day, which is when the panels are generating, so a good share of that output can be used in the building rather than sent back to the grid.

This array joins solar already installed on the newer school building when it was constructed, so the site now makes more of its own electricity than before. The school has recently moved to air source heat pumps for its heating as well, part of a wider shift away from fossil fuels.