About the Savings Calculator
Solar bill savings are the reduction in your monthly and annual electricity bill from a rooftop system — solar offsets the grid units you would otherwise buy, valued at your DISCOM tariff, plus any net-metering credit for surplus you export. The three levers are how much you generate, how much you self-consume, and your tariff.
Formula
Annual savings ≈ Annual generation (kWh) × Effective tariff (₹/kWh)
- Annual generation
- System kW × your state's kWh/kW/year yield
- Effective tariff
- Retail tariff for self-consumed units; net-meter credit for exported units (₹/kWh)
Monthly savings ≈ Annual savings ÷ 12
How to calculate it
- 1Estimate annual generation from system size and your state's specific yield (≈1,400–1,600 kWh/kW/year in most of India).
- 2Value the units you use directly at your retail slab tariff — solar usually offsets your most expensive top-slab units first.
- 3Credit the surplus you export at your DISCOM's net-metering rate.
- 4Add the two to get annual savings, then divide by 12 for a monthly figure.
Worked example
A 3 kW rooftop system generating ~4,500 kWh/year for a household on an ₹8/kWh top slab saves roughly 4,500 × ₹8 = ₹36,000/year, or about ₹3,000/month — and that grows as grid tariffs rise.
What you can calculate
- Monthly savings
- Grid export
- Time-of-use rates
- Peak demand analysis
Standards & references
Frequently asked questions
How much can I save with rooftop solar?
A well-sized residential system typically cuts 70–90% of the electricity bill; many households with a 3–5 kW system save ₹30,000–₹60,000 a year. The exact figure depends on your consumption, tariff slab, and how much of the generation you use directly versus export.
Do my savings increase over time?
Yes. Grid tariffs in India rise a few percent most years, so the units your solar offsets become more valuable each year, while your system cost is fixed. Even after ~0.5%/year panel degradation, real savings generally increase over the 25-year life.
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