Solar vs grid power, rupee by rupee
The cheapest electricity is the electricity you generate yourself. We break down the full comparison, installation, subsidy, savings, and 25-year value, for four types of Indian household.
Understanding the full cost picture
Most people compare solar and grid on the wrong metric, they look at installation cost versus monthly bill, without accounting for the lifetime value of solar. The correct comparison includes the total cost of installation after subsidy, the system's generation over 25 years, projected grid tariff increases, and the residual value of the system.
| Household | Monthly units | Grid bill (2025) | Solar size | Post-subsidy cost | Annual saving | Payback | 25-yr net |
|---|---|---|---|---|---|---|---|
| 1BHK / Small | 100–150 | ₹900–1,400 | 1–1.5 kW | ₹40k–70k | ₹10k–16k | 3.5–4.5 yrs | ₹2.5–3.5L |
| 2BHK / Medium | 200–280 | ₹1,800–2,600 | 2–2.5 kW | ₹85k–1.0L | ₹20k–28k | 3.5–4.5 yrs | ₹4.5–6L |
| 3BHK / Large | 300–450 | ₹2,800–4,200 | 3–4 kW | ₹1.1L–1.7L | ₹30k–45k | 3.5–4.5 yrs | ₹7–10L |
| Villa / 4BHK+ | 500–900 | ₹5,000–9,500 | 5–8 kW | ₹2.3L–3.8L | ₹55k–90k | 3.5–5 yrs | ₹12–19L |
Savings assume a 7.5% annual tariff increase and 0.5% annual solar output degradation. Subsidy figures are per PM Surya Ghar Muft Bijli Yojana 2025–26.
What about cloudy days and rain?
A common misconception. Modern solar panels generate electricity from diffused light, not just direct sunlight. Even during overcast conditions, a panel typically operates at 20–40% efficiency. Net metering means excess power generated on sunny days is fed back to the grid, earning you credits to draw from on cloudy days. Your effective solar "uptime" across the year is much higher than most people assume.
Key insight, peak sun hours
Bengaluru receives an average of 5.1 peak sun hours per day. Mumbai: 4.8. Chennai: 5.4. Delhi: 5.5. Every major Indian city receives enough sunlight to make rooftop solar financially compelling.
Grid electricity: the true cost nobody calculates
Your electricity bill is just the direct cost. The full cost of grid power, when you account for power cuts, voltage fluctuations that damage appliances, inverter-battery replacement, and the productivity loss from outages, is significantly higher than the tariff alone suggests.
- Average inverter-battery replacement: ₹18,000 every 3.5 years
- Appliance damage from voltage fluctuation: ₹5,000–₹15,000 per household per decade
- Power cuts: 1.5–4 hours/day in Tier 2/3 cities, a productivity and comfort cost
- Solar with battery or net metering eliminates all three of these costs
Find your row
Which household are you? Get sized in seconds.
Don't guess between table rows. Enter your bill and city and the calculator returns your exact system size, payback and 25-year net.
Size my system
Keep reading
Next in the library
Not sure which brands fit your home?
Solar Match picks a panel + inverter for your city, roof and budget, reasoning shown, in about a minute.
Find my match
Free · no number needed
Your next step
Use the free tools, decide for yourself.
We're an independent educational platform, not a sales channel. No forms, no calls, no pressure, explore the tools and go at your own pace.