Calculate exactly how much you'll save on electricity bills after installing rooftop solar. Uses your city's sun hours and your actual tariff slab for accurate results.
How Solar Savings Work
Solar panels generate electricity during daylight hours. Every unit generated offsets a unit you would have purchased from the grid. Your savings equal units generated × your electricity tariff rate.
Sun Hours by City
City
Peak Sun Hours/Day
Units/kW/Month
Jaipur / Jodhpur
5.5–6.0 hrs
165–180 units
Ahmedabad / Surat
5.2–5.7 hrs
156–171 units
Delhi / Lucknow
4.8–5.3 hrs
144–159 units
Hyderabad / Pune
5.0–5.5 hrs
150–165 units
Bengaluru / Chennai
4.8–5.2 hrs
144–156 units
Mumbai
4.5–5.0 hrs
135–150 units
Kolkata / Bhubaneswar
4.5–5.0 hrs
135–150 units
Northeast India
3.5–4.5 hrs
105–135 units
What Affects Your Savings?
Tariff slab — Higher slabs (>300 units/month) often pay ₹7–10/unit in India. Moving to a lower slab by using solar saves at the highest rate first.
System orientation — South-facing roofs get maximum generation. East/West roofs get 85–90% of optimal. North-facing gets 70–75%.
Shading — Even partial shade on one panel can reduce system output by 10–30%. Use micro-inverters or power optimisers if shading is unavoidable.
Panel degradation — Panels degrade ~0.5%/year. After 25 years, your system produces ~87% of Year 1 output. Our calculator applies this automatically.
Frequently Asked Questions
A 3 kW solar system produces approximately 360–540 units per month in India (120–180 units/kW/month), depending on the city and sun hours. Rajasthan gets the most (up to 180 units/kW/month) while the Northeast gets the least (~105 units/kW/month).
A 3 kW system saving 400 units/month at ₹7/unit saves ₹2,800/month or ₹33,600/year. Actual savings depend on your consumption, tariff slab, and system generation. Higher tariff slabs mean larger savings and faster payback.
Quality solar panels come with a 25-year performance warranty. They degrade at approximately 0.5–0.7% per year. After 25 years, panels typically still produce 80–85% of rated capacity. The inverter (5–10 year warranty) may need replacement once during the system's life.
Surplus electricity can be exported to the grid through net metering. Your DISCOM credits the exported units against your bill. If exports exceed imports, you receive a payment (in most states) or carry credits forward. Use our Net Metering Calculator to quantify this income.