Everyone knows solar "saves money" — but how much, really, for a normal Chennai home? Instead of vague promises, this guide walks through three real household bill scenarios, shows the monthly and yearly savings, and explains exactly how net metering turns sunlight into a smaller TANGEDCO bill.
Why Chennai Homes Save So Much
Two things make Chennai one of the best cities in India for solar returns. First, abundant sunlight — Chennai gets strong, consistent irradiation almost year-round, so each installed kW generates 4–5 units per day. Second, TANGEDCO's tiered tariffs — the more you consume, the higher the per-unit rate on your upper slabs. Solar shaves off exactly those expensive top-slab units first, which is why the savings feel larger than the raw unit count suggests.
How Net Metering Works (in Plain English)
Your rooftop system generates power during the day. Whatever your home doesn't use immediately flows back to the grid, and TANGEDCO's bidirectional meter records it as a credit. At night, when your panels aren't producing, you draw from the grid and those imported units are offset against your daytime credits. You're billed only on the net — hence "net metering." A well-sized system can bring your energy charges close to zero, leaving just the small fixed charges.
Real Bill Examples: 3 Chennai Households
Below are three representative scenarios based on common Chennai consumption patterns. Figures are illustrative for 2026 and rounded for clarity.
2 BHK apartment, moderate usage
A couple in a 2 BHK using around 300 units/month, with a pre-solar bill of roughly ₹2,200. They install a 2kW system generating ~240–280 units/month.
| Monthly bill before solar | ₹2,200 |
| Monthly bill after solar | ₹300–₹500 (fixed charges) |
| Monthly saving | ~₹1,700–₹1,900 |
| Yearly saving | ~₹20,000–₹23,000 |
| Net system cost (after subsidy) | ₹60,000–₹80,000 |
Payback: roughly 3.5 years.
3 BHK independent house, one or two ACs
A family of four using around 450 units/month, with a pre-solar bill of roughly ₹3,400. They install a 3kW system generating ~360–450 units/month.
| Monthly bill before solar | ₹3,400 |
| Monthly bill after solar | ₹400–₹700 (fixed + small net) |
| Monthly saving | ~₹2,700–₹3,000 |
| Yearly saving | ~₹33,000–₹36,000 |
| Net system cost (after subsidy) | ₹1,02,000–₹1,32,000 |
Payback: roughly 3–4 years. This is the most common Chennai scenario.
4+ BHK villa, multiple ACs
A larger household using around 700 units/month, with a pre-solar bill of roughly ₹6,500. They install a 5kW system generating ~600–750 units/month.
| Monthly bill before solar | ₹6,500 |
| Monthly bill after solar | ₹600–₹1,000 |
| Monthly saving | ~₹5,500–₹5,900 |
| Yearly saving | ~₹66,000–₹70,000 |
| Net system cost (after subsidy) | ₹2,12,000–₹2,52,000 |
Payback: roughly 4 years.
Savings Over the System's Lifetime
The monthly numbers are just the start. Solar panels are warrantied for 25 years, and TANGEDCO tariffs tend to rise over time — which means your savings actually grow each year as grid power gets more expensive. Here's the long view for the typical 3kW home:
| Period | Approx. Cumulative Saving |
|---|---|
| Year 1 | ~₹33,000 |
| By Year 4 (payback point) | System cost recovered |
| Years 5–25 (near-free power) | ₹8–12 lakh+ |
Lifetime figures assume modest annual tariff increases and account for gradual panel degradation. Real returns vary by household.
What Affects Your Actual Savings?
Your real numbers depend on a few factors we assess during a site survey:
| Factor | Impact on Savings |
|---|---|
| Roof orientation & tilt | South-facing, unshaded roofs generate the most |
| Shading (tanks, trees, buildings) | Reduces generation during shaded hours |
| Your consumption slab | Higher usage = higher per-unit savings |
| System sizing | Right-sized systems maximise net-metering value |
| Panel & inverter quality | Tier-1 modules sustain output over decades |
See Your Own Savings Estimate
Send us your last TANGEDCO bill and we'll calculate your exact monthly and yearly savings — free, with no obligation.
Get My Free Savings EstimateFrequently Asked Questions
How much can I save with solar on my Chennai home?
A 3kW system saves roughly ₹2,500–₹3,800 per month (~₹30,000–₹45,000 a year). Larger 5kW systems save ₹4,500–₹6,000 monthly. Savings depend on your consumption, roof, and tariff slab.
Can solar reduce my electricity bill to zero?
A correctly sized system generating as many units as you consume can bring your bill down to just the fixed charges, effectively removing your energy charges through net metering.
How does net metering increase my savings?
Surplus power you export to the grid is credited against the units you import at night, so you're billed only on your net consumption — maximising savings.
How long before solar pays for itself?
After the PM Surya Ghar subsidy, most Chennai systems pay back in about 3–4 years, then generate for 20–25 years — making the rest almost pure return.