Singapore Solar & Battery Payback Calculator

Your monthly bill is converted to annual consumption at the live SP Group tariff. A system is then sized to generate about 70% of that consumption (90% if you add a battery) at Singapore's typical solar yield of ~1,150 kWh per kWp per year, capped by what your roof type can physically fit. Energy you use on-site displaces the full tariff; surplus exports earn Simplified Credit Treatment (SCT) credits at roughly 25–26 cents/kWh. Savings can never exceed what the sized system actually generates.

Without a battery, surplus midday solar exports at ~25–26 cents/kWh while you buy evening electricity at the full 34.78 cents/kWh tariff. A battery stores that midday surplus for evening use, lifting self-consumption from ~60% to ~85% of generation. Singapore's wholesale market prices evening-peak energy ~26% above the midday solar window, which is why battery economics flipped in 2026 as tariffs hit record highs and battery hardware prices fell.

It is a planning estimate built on published data: the live SP tariff, EMA wholesale statistics, and Sunollo's published package pricing. Your actual number depends on roof orientation, shading, and your consumption pattern — a free on-site assessment gives you a firm quote, and Sunollo's SunolloCare savings guarantee backs the delivered performance.

Fair question — Sunollo installs solar, so we have an interest in the answer. That's exactly why nothing here is hidden: every rate, yield, and price is listed below with a source you can check yourself, the tariff comes from a public CC-BY-licensed API, and savings are hard-capped by what a system can physically generate on your roof type. The calculator also shows unflattering answers honestly: a small bill on a big package gets a long payback, and if your roof can't cover your usage, it says so. If you think an assumption is wrong, the methodology is right here to argue with.

Yes, free. Click "Embed this calculator on your site" above and copy the snippet. The embed auto-sizes to fit your page, always uses the current quarter's SP tariff, and never goes stale. Publishers and partners can add a partner tag so leads from their site are credited to them.

• SP Group regulated tariff: 34.78 cents/kWh incl. 9% GST (Q3 2026), fetched live from the Sunollo Real Tariff Index (CC-BY-4.0) and updated every quarterly SP revision.
• Yield: ~1,150 kWh per kWp per year, Singapore's typical average. Panels are 665 W (~3.1 m² each); auto-sizing targets your property's typical roof capacity, with an outer limit for larger-than-typical roofs available via "Adjust system size."
• Self-consumption: ~60% of generation used on-site (solar-only) or ~85% (with battery), based on Sunollo fleet data. Surplus is credited under Simplified Credit Treatment (SCT) at ~25–26 cents/kWh.
• Singapore's wholesale market (EMA/NEMS data) has averaged ~S$147/MWh in the solar export window (10am–4pm) versus ~S$185/MWh in the evening peak (7–11pm) — the ~26% gap a battery captures.
• Costs from Sunollo's published pricing: packages from an S$14,500 floor, ~S$1,000–S$1,200 per kWp for larger systems, battery add-ons of S$8,000–S$20,000 for 5–20 kWh.