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ROI Calculator

What might solar cost on your site — and when does it pay back?

A rough estimate in 30 seconds. Enter five numbers, get a ballpark system size, cost range, and payback period. For an actual quote matched to your roof, book a consultation.

Your situation

$
Your average monthly electricity cost, in US dollars.
Used to estimate your typical load pattern and applicable rate.
Peak sun hours vary by region. Pick the closest match for a rough estimate.
How much of your electricity you use during sunlight hours. Higher means better solar economics.
$
Your average per-kWh rate. Asia ranges roughly $0.08 – $0.25. Check your bill if unsure.
How this estimate is calculated

We use a simple five-step calculation:

  1. Annual electricity cost = monthly bill × 12
  2. Annual consumption = annual cost ÷ rate per kWh
  3. System size = consumption ÷ (peak sun hours × 365 × 0.80 system efficiency factor)
  4. Annual savings = (self-consumed kWh × full retail rate) + (exported kWh × lower feed-in rate estimate)
  5. Simple payback = indicative system cost ÷ annual savings

Cost estimates use broad Asian market ranges of roughly $700–$1,200 per kWp for residential and $600–$1,000 per kWp for commercial/industrial installations. The 25-year savings calculation accounts for one inverter replacement (~8% of system cost at year 11) and 0.5% per year panel degradation. Electricity rate increases are assumed to be zero — a conservative assumption.

Many important factors are not modelled: time-of-use tariffs, demand charges, tax incentives, specific net-metering rules, roof orientation/shading losses, and component variation. A real proposal accounts for all of these.

Ready for numbers that match your actual roof?

Book a 45-minute consultation. We will review your bill, the site, the tariff, and produce real numbers — not estimates.

Book consultation