The Real Cost of Waiting a Year to Install Solar in Singapore

Waiting a year to decide on solar has exactly one real, quantifiable cost: a year of savings and export credit that never happens. It is worth naming precisely, not as a pressure tactic, but because most homeowners weighing whether to wait have never actually seen the number.

• A year of delay on a typical 10kWp system costs roughly S$3,100 in generation and export credit that is genuinely lost, not deferred to later.
• Waiting does not push back a system's own degradation clock, since that starts from the actual commissioning date, not a fixed calendar date.
• A rising electricity tariff makes waiting more costly, not less, since self-consumed solar becomes worth more the moment a system is running.
• Waiting is still the right call for a genuine competing priority, a planned sale, re-roofing, or simply not having the cash yet, none of which this number argues against.

What does a year of delay actually cost, in real numbers?

Using Sunnify's reference figures for a 10kWp system, Singapore's 1,106 kWh/kWp annual yield, and a 25% self-consumption split: roughly S$2,141 a year in SCT export credit plus roughly S$962 a year in self-consumption saving, close to S$3,100 combined. That figure applies for every full year a decision to go solar sits unmade, not deferred to whenever installation eventually happens, a year without a system captures none of that generation at all.

Does this number hold up even on a conservative estimate?

Yes, and it is worth checking specifically since an optimistic number would undermine the whole point. The roughly S$3,100 figure above already uses Sunnify's standard reference assumptions, the same figures quoted throughout this site, not an inflated best-case scenario built specifically to make waiting look worse.

A more conservative P90 estimate trims the generation side of that figure somewhat, reflecting a below-median weather year rather than a typical one, but does not come close to erasing it. See the P50/P90 estimates guide for what these terms actually mean and how much spread separates them for a Singapore installation specifically.

Does waiting actually push back when a panel's degradation clock starts?

No, and this is worth correcting directly, since the intuition runs the wrong way. A panel's roughly 0.5% annual degradation is tied to its own age from the date it is actually commissioned, not to a fixed calendar date every panel shares.

Waiting a year does not preserve a year of peak, undegraded output for later use. It simply means that specific year of generation never happens for this household at all, a straightforward missed year, not a postponed one.

Does a rising tariff make waiting more or less costly?

More costly, if anything. Singapore's electricity tariff rose 17% in a single quarter in mid-2026, to S$0.3478 per kWh including GST, one of the larger single-quarter moves in recent years. A household without solar pays that full increase on every kWh imported, with nothing offsetting it.

A household that already has solar running captures a meaningfully bigger self-consumption saving the moment a tariff rises, since that saving is calculated directly against the retail rate. Waiting through a tariff increase with no system installed is the one scenario where delay is unambiguously more expensive than the baseline calculation above suggests, not less.

Is there ever a genuine upside to waiting?

Occasionally, though it is a smaller and less certain effect than the guaranteed cost of missed savings. Equipment prices and panel efficiency both continue to improve gradually over time, so a system installed a year from now may cost marginally less per kWp or generate marginally more from the same roof area than one installed today.

In practice this effect is modest year to year and has not historically outweighed a full year of missed S$2,000 to S$4,500 in savings for a typical landed home system, which is why waiting purely to chase a better future price rarely pays off compared to installing now and capturing that year's savings instead.

When does it genuinely make sense to wait?

When the reason is a real, specific constraint rather than indecision. Planning to sell or move within the next year or two changes the calculation meaningfully, since a shorter ownership window reduces how much of the 25-year return a specific household actually captures. Planned re-roofing or major Addition and Alteration works should generally happen before solar goes on, covered in sequencing solar with renovation and re-roofing.

Simply not having the cash available yet, or preferring to save toward paying outright rather than financing, is also a genuine, reasonable reason, not indecision dressed up as one. A homeowner weighing a loan against waiting to save the full amount is making a real financing trade-off, covered separately below, not the kind of open-ended delay this figure is actually arguing against.

Does the calculation change if I am financing rather than paying cash?

Not much, since a delayed decision postpones both the loan and the savings by the same period either way. See solar financing in Singapore for how financing itself is structured, separate from the timing question covered here.

What's the actual next step?

Run the Sunnify solar estimate to see the specific number for your own roof, then weigh it honestly against whatever the actual reason for waiting is. See is solar worth it in Singapore for the full economics this figure sits inside, and what happens if your installation itself gets delayed for a different, project-timeline version of delay once you have already decided to proceed.