Is Solar Worth It in Singapore? The Honest Verdict

For most Singapore landed homes, solar is worth it. A typical system pays back its installed cost in 4 to 5 years, then keeps generating electricity for another 20-plus years at effectively zero marginal cost. That is the honest headline.

The real work is in the specifics: how the payback math actually works, which property types and usage patterns get the best return, what can go wrong, and the small number of situations where the answer genuinely flips to no. This article walks through all of it using Sunnify's own verified figures, not marketing averages.

• A typical 12 to 15 kWp system on a Singapore landed home pays back its installed cost in 4 to 5 years, then generates free electricity for the remaining 20-plus years of its 25-year panel life.
• Singapore's retail tariff is S$0.3478/kWh and the SCT solar export rate is S$0.2581/kWh, a roughly 26% gap that makes self-consumption timing the single biggest lever on payback speed.
• Across ordinary property types, typical system sizes run from 8 to 12 kWp for a semi-detached roof half up to 15 to 20 kWp for a standard bungalow, with payback holding in a fairly narrow 3.7 to 5.2 year band regardless of size.
• Four situations genuinely weaken the case: heavy shading, selling the home within 2 to 3 years, a roof that needs repair soon, and very low daytime electricity usage.

How solar actually pays for itself

Every solar payback calculation comes down to one mechanism. A solar panel generates electricity during the day, and that electricity is worth one of two different prices depending on what happens to it. Electricity a household uses immediately offsets electricity that would otherwise be bought from SP Group at the full retail tariff.

Electricity the household does not use gets exported to the grid and credited at a separate, lower rate. The gap between those two prices is the entire reason self-consumption share matters more to the payback math than almost any other variable in the system.

What counts as self-consumption, and why does it matter more than roof size?

Self-consumption is the share of a system's generation that a household uses directly as it is produced, rather than sending it back to the grid. Sunnify's reference model assumes 25% self-consumption for a typical household, meaning three-quarters of generation gets exported.

A household that runs its aircon, pool pump, EV charger, or home office equipment during daylight hours captures a meaningfully higher share, which improves payback without changing anything about the system itself. Two identical 15 kWp systems on two identical roofs can have genuinely different payback periods purely because of when the households inside them use electricity.

Why is the export rate lower than the retail tariff?

Electricity exported to the grid is credited under the Simplified Credit Treatment (SCT) scheme, currently S$0.2581/kWh, against a retail tariff of S$0.3478/kWh, a difference of roughly 26%.

This is not a Sunnify pricing decision. SP Group and EMA set both rates, and the gap reflects the difference between the retail price a household pays, which includes network charges and other cost components, and the value of electricity fed back into the grid.

Homeowners on an OEM electricity retailer plan instead fall under the Enhanced Central Intermediary Scheme (ECIS), a variable rate tied to the half-hourly wholesale electricity price rather than a single fixed figure like the SCT rate. Singapore has no net metering scheme; exported solar electricity is credited against the bill, not offset one-for-one against future usage.

How does solar actually change my SP Group bill?

A household with solar does not stop receiving an SP Group bill. Self-consumed generation reduces the amount of grid electricity bought and billed at the retail tariff, while exported generation appears as a separate credit at the SCT rate, netted against the bill rather than eliminating it. A household still draws grid electricity at night and on low-generation days, so the bill becomes smaller and more variable, not zero.

What does a system cost, and what does it return, by property type?

Cost and return both scale with system size, and system size is mostly a function of usable roof area. The table below uses Sunnify's verified cost and generation figures across the three most common Singapore landed home types.

A documented Sunnify installation at Mount Sinai, a 20.6 kWp system across 42 panels on a pitched detached roof, sits at the upper end of this bungalow range and is currently saving the household roughly S$6,400 a year, a real figure rather than a modelled one.

Good Class Bungalows are a separate case. A GCB's much larger roof footprint commonly supports 30 to 120 kWp, well beyond the 8 to 20 kWp range typical of the ordinary property types above. See the dedicated GCB sizing breakdown for that specific math, since the achievable size depends heavily on the individual roof rather than a single typical range.

Payback holds in a fairly narrow band across ordinary property types because cost per kWp and generation per kWp are both roughly consistent across Singapore. A smaller semi-detached roof pays back slightly slower mainly because fixed costs like scaffolding, permits, and grid connection fees are spread across less generating capacity.

What is the real 25-year return, not just the payback year?

Payback marks the point where cumulative savings equal the installed cost, not the end of the benefit. A 15 kWp terrace house system that pays back in roughly 4 years continues generating for a further 21 years of its 25-year rated life, with output declining by only 0.5% a year from panel degradation.

Applying that degradation to a first-year savings figure of approximately S$4,654, calculated at 25% self-consumption against the current retail and SCT rates, total 25-year savings after subtracting the initial installed cost typically land in the S$50,000 to S$70,000 range for a system this size, before accounting for one likely inverter replacement partway through the panel's life.

Smaller semi-detached systems return proportionally less in absolute dollars than a 15 kWp terrace system; larger bungalow systems return proportionally more. See the total cost of ownership framework for the full 25-year model, including inverter replacement and ongoing maintenance costs.

What actually separates a good case from a mediocre one?

Two households with identical roofs and identical system sizes can end up with meaningfully different payback periods. The difference almost never comes down to the panels themselves. It comes down to when electricity gets used and how much direct sun the roof actually receives.

Does timing self-consumption during the day actually matter?

Yes, directly and substantially. Running a pool pump, EV charger, or aircon on a timer during peak generation hours, roughly 10am to 4pm, shifts consumption from grid-priced night usage to self-consumed solar generation, converting electricity valued at the S$0.2581/kWh export rate into electricity valued at the S$0.3478/kWh retail rate.

Lifting self-consumption from Sunnify's 25% reference assumption to 35% or 40%, achievable for a household with a home office or an EV charged during the day, can shorten payback by roughly six months to a year on a typical system, without adding a single panel.

How much do roof orientation and shading change the numbers?

A roof with full, unobstructed sun exposure performs close to Singapore's stated 4.33 peak sun hour daily average. A roof partially shaded by a neighbouring structure or mature trees for part of the day, or one facing away from the optimal orientation, can lose 10% to 25% of expected generation, which stretches payback proportionally. This is a site-specific factor a satellite-based online estimate cannot fully judge.

A proper roof assessment during a site review is what actually confirms it. See the roof suitability checklist for the specific factors a site review checks.

What can go wrong, and what does it actually cost?

The 25-year return assumes the system performs as designed and the installer stands behind the work. Three real risks can disrupt that.

An inverter typically needs replacement once within a 25-year system life, commonly in year 12 to 15, at a cost that should already be built into any credible 25-year savings projection. A savings estimate that ignores this cost entirely is incomplete, not conservative. See evaluating a solar savings guarantee for the specific claims worth questioning before signing.

Installer quality varies more than panel quality does in Singapore's market. A poorly sized inverter, incorrect roof penetration and waterproofing, or under-specified cabling can all reduce real-world generation below the modelled figure, or create a maintenance problem years later, without the panels themselves being at fault.

This is why confirming a Licensed Electrical Worker handled the installation, an EMA requirement for every Singapore solar system, matters more to long-term return than panel brand selection alone. See the LEW requirements guide for what to verify before signing.

A roof issue that surfaces after installation, most commonly a waterproofing failure on a flat or ageing roof, can force a temporary panel removal to fix the underlying roof, adding real cost and downtime that a purely financial model does not capture. This is why the roof waterproofing guide exists as a pre-installation check, not an afterthought.

When is solar genuinely not worth it?

Four specific situations weaken the case enough that the honest answer moves toward no.

Does heavy roof shading rule out solar?

Heavy shading from mature trees or taller neighbouring structures across most of the day can cut generation by 25% or more, stretching payback well past 5 years and sometimes past the point where it completes within the panels' useful life. A site review, not the online estimate, is what confirms whether this applies to a specific roof.

What if I am planning to sell within a few years?

Selling the home within 2 to 3 years means payback is unlikely to complete before the system changes hands. This does not automatically make solar a bad decision, since a documented, professionally installed system still transfers real value to a buyer, but the return should be evaluated as what a buyer inherits rather than what the seller personally recovers. See selling a home with solar panels for how this actually plays out.

Should roof repairs happen before or after installing solar?

A roof needing structural repair, re-tiling, or waterproofing work soon should have that work done first. Removing and reinstalling panels to fix an underlying roof problem adds real labour cost on top of the repair itself, and is avoidable by sequencing the two correctly.

Does very low daytime electricity usage rule out solar?

A household with very low daytime electricity usage, for example an empty house on weekdays with no home office, EV, or pool equipment running during sun hours, exports the large majority of its generation at the lower SCT rate rather than the retail rate. The system still pays back, generally within 4 to 5 years, but sits toward the slower end of that range.

Outside these four situations, the 25-year economics consistently favour installing.

Does solar increase property value in Singapore?

There is no reliable Singapore-specific data quantifying an exact resale premium for a home with solar installed, so treat any specific percentage claim with scepticism. What can be said honestly is this: a documented, professionally installed system with remaining panel life is a genuine asset a buyer inherits, either continuing to pay back or, if payback has already completed, delivering pure savings from the buyer's very first month of ownership.

How does this compare to other places to put the money?

A 4 to 5 year payback, followed by two decades of continued return, compares favourably to most low-risk savings instruments available to a Singapore homeowner. Two features make it a genuinely different kind of return, not just a faster one. First, once the panels are paid off, the return continues with no further contribution required.

Second, the return is largely insulated from Singapore's electricity tariff trend. Since retail tariffs have generally moved upward over recent years, the value of a fixed asset generating free electricity at the current retail rate tends to rise with each tariff increase, rather than being fixed at today's terms.

Is solar still worth it if electricity tariffs fall?

Yes, though the margin narrows. Even if the retail tariff dropped meaningfully from its current S$0.3478/kWh, self-consumed generation would still offset a real cost, and export credit at the SCT rate would still return value from generation that would otherwise be wasted.

Payback would simply take longer than the 4 to 5 year range typical today. Singapore's tariff has historically moved with global fuel costs in both directions, so this is worth acknowledging honestly, but it does not change the underlying mechanism, only its speed.

What is the actual next step?

An online estimate, including Sunnify's own, is a starting reference point built on averages: typical roof area, typical shading, typical usage. The only way to get an actual number for a specific roof is a site review, which checks orientation, shading, existing roof condition, and available electrical supply directly.

Run the Sunnify solar estimate first to see an approximate system size and cost. If the numbers look worth pursuing, request a site review to convert that estimate into an actual, roof-specific figure.

For the financing side of that decision, see solar financing options, covering cash purchase, loans, and rent-to-own.

Do I need a battery for solar to be worth it?

No. The payback and return figures throughout this article assume no battery, and a battery is a separate, additional purchase with its own independent payback calculation, typically longer than solar alone because battery hardware costs more per kWh than solar panels do per kWp.

A battery mainly adds value by raising effective self-consumption and by providing backup power during an outage, neither of which is required for solar itself to be worth it. See the battery sizing guide if that is the next question worth answering.