Merryn Avenue Solar Installation: 14.7 kWp on a Flat Roof, $4,560 a Year

30 black monocrystalline panels on aluminium ballast frames, zero roof penetrations, facing north-south across the roof's ridge. Here's what this 14.7 kWp installation in the Caldecott neighbourhood, near the Thomson corridor, actually involved from start to finish.

What was actually installed at this home?

30 black monocrystalline panels totalling 14.7 kWp, mounted on aluminium ballast frames across a large flat concrete roof near the Thomson corridor. No drilling and no roof penetrations, the frames' own positioning and weight distribution hold the array in place across the full roof area of this Caldecott property.

Why does the north-south orientation across the ridge matter?

The array was laid out to follow the roof's own ridge line running north-south, a deliberate design choice to keep panels at a consistent, favourable orientation across the full array rather than splitting it awkwardly around the ridge's shape. See how orientation actually affects generation in Singapore for why this still matters even at a near-equatorial latitude.

Why ballasted mounting for a system this size?

A large, unobstructed flat concrete roof gave this installation enough area to support 30 panels on ballast frames without needing an elevated tilt structure or a more complex multi-section layout. See how ballast weight actually gets calculated for the real engineering standard, SS EN 1991-1-4, behind sizing a system like this correctly.

Avoiding roof penetrations entirely on a system this size is a meaningful advantage: more panels generally means more potential penetration points on a mounting system that uses them, a risk this approach sidesteps completely.

Does a 30-panel array need different maintenance access than a smaller one?

Not fundamentally, though a larger array means more total panels to walk between and inspect during a periodic clean or health check. Ballast frames sitting proud of the roof surface, rather than a flush penetrating mount, actually make individual panel access somewhat easier, since there's a consistent gap to walk or reach between rows.

See what an annual health check on a system like this actually covers for what ongoing maintenance looks like regardless of array size.

How much does this system actually save?

Around $380 a month, roughly $4,560 a year, based on Sunnify's projection for this 14.7 kWp system at the Q3 2026 EMA regulated tariff of S$0.3478/kWh, 25% self-consumption, and an SCT export credit of S$0.2581/kWh, the same assumptions applied consistently across every documented Sunnify installation regardless of neighbourhood.

How does this compare to a smaller ballasted system?

At roughly 20% larger than the 12 kWp ballasted system at Lim Ah Pin Road, this installation's projected savings scale up correspondingly. Both share the same fundamental mounting logic, a flat concrete roof supporting ballast frames without penetration, at genuinely different scales and in different neighbourhoods.

What would a similar large flat roof need to consider?

Confirm the roof's structural capacity actually supports a larger ballast array before assuming size scales freely, since a bigger system means proportionally more weight the same roof structure has to carry, not a simple multiple of a smaller system's already-confirmed load. See waterproofing and structural considerations for what a proper assessment should actually cover before committing to a specific array size.

Run the full roof suitability checklist to assess your own roof, and the Sunnify solar estimate to see what a similar system could save on your property.