Rac calculator

RAC Max System Size Tool

Estimate the maximum allowed system size (kWp) from your average monthly usage.

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Step 1
Max system size from your monthly usage

Based on the RAC guideline shown in the policy:Monthly kWh ≥ kWp × 5 × 30 × 0.75.

Customer type
Residential cap shown here: 10 kWp.
Avg monthly usage (kWh)
Tip: use your last 12 months average from your utility bills.
Panel watts (for panel count)
Result
Enter your average monthly kWh to see the maximum allowed system size.
Max allowed (kWp)
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Panels at max (approx)
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This is a guidance tool. Final approval depends on the official RAC / utility review.
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Quick links
Learn the policy

Want the details and official links? Use the RAC education page (plain-language).

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What to prepare
Good inputs = better result
  • Last 12 months usage (kWh) average (best)
  • Planned big loads (EV, extra A/C, apartment, pool)
  • Residential vs Commercial classification
  • Target panel wattage (e.g. 410W)
Rule used: Monthly Usage (kWh) ≥ System Size (kWp) × 5 × 30 × 0.75.