Case Study: How a Bukit Timah GCB Saves S$16,000 a Year with Solar

The home

This is a large tile-roof Good Class Bungalow in the Bukit Timah area of District 10, one of Singapore's established landed-home districts. Like many GCBs, it pairs a generous roof with high daytime electricity demand, from multi-zone air conditioning and pool filtration to general household load, which makes it a strong candidate for solar.

The challenge: partial shade from mature trees

The catch on this site was shading. Mature trees around the perimeter cast partial shade across the eastern part of the roof at certain times of day. On a conventional system, panels are wired in series strings, and when one panel in a string is shaded, its drop in output drags down the whole string. On a leafy landed property, that can quietly cost a meaningful share of annual generation.

The solution: panel-level optimisers

Rather than simply avoiding the shaded area, Rezeca specified SolarEdge power optimisers on each panel. Optimisers let every panel operate at its own maximum, so a shaded module no longer holds back its neighbours. On this roof the difference was measured at a 4 to 6% improvement in output compared with a standard string configuration, alongside panel-level monitoring that flags any single panel that underperforms. For homes with trees, dormers or complex rooflines, this is often the difference between a system that merely works and one that reaches its full potential.

The numbers

At 40.05 kWp, the system generates an estimated 50,000 kWh of clean electricity a year, covering a large share of the household's daytime consumption, with surplus exported to the grid under Singapore's Simplified Credit Treatment (SCT) scheme and credited on the SP Group bill. Annual savings work out to around S$16,000. On a GCB of this scale that points to a payback within the shorter end of the typical landed-home range, after which the panels keep generating under their 25 to 30-year warranties. Our guide to solar payback periods in Singapore explains what drives that.

Why it matters for shaded landed homes

Many of Singapore's most attractive landed homes sit among mature greenery, and owners often assume shade rules solar out. It rarely does. The right response is good design: assess where and when shade falls, then choose the electronics that handle it, whether that is panel-level optimisers, microinverters, or a careful string layout. The roof itself matters too; this was a tile roof, and our guide on solar by roof type covers how tile, metal and concrete each shape a system.

Frequently asked questions

Can I install solar if my house is shaded by trees?
Usually yes. Partial shade is managed with panel-level optimisers or microinverters, which let each panel produce independently so a shaded module does not drag down the rest. A site assessment maps where and when shade falls and designs around it.

What do SolarEdge optimisers actually do?
They let each panel run at its own optimum and report its output individually. On a partly shaded roof this can recover several percent of annual generation and makes it easy to spot a single underperforming panel.

How much can a GCB save with solar in Singapore?
It depends on roof size and consumption, but larger landed homes commonly save five figures a year. This Bukit Timah system saves around S$16,000 annually.

Considering solar on a shaded or leafy plot?

If your home sits among trees or has a complex roof, that is exactly the kind of site worth assessing properly rather than ruling out. We are happy to show you what your roof can do and what you would save. Book a free site assessment.

Rezeca Renewables has installed solar for landed homes and businesses across Singapore since 2009, with over 1,500 installations and 45+ MWp to date, including 1,300+ residential landed homes.