TNEB / EB bill calculator 2026 (new 200 free units rule).
Free TNPDCL (TANGEDCO) bill calculator for Tamil Nadu homes. Enter units or the rupee amount and see the exact 2026 bill, slab by slab, the old-vs-new rule difference, and what solar would save.
TNEB bill calculator with solar savings
Your bill today
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Your estimate Indicative, incl. GST
- System price
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- PM Surya Ghar subsidyCentral, paid to your bank
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- Tamil Nadu top-upG.O. (Ms) No. 102
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- Tax benefit40% accelerated depreciation may apply; ask your CA
- Year 1
- You pay
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How your bill is calculated
Solar loan EMI
- System price (mid-range)
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- Down payment
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- Loan
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PM Surya Ghar loans from public-sector banks: about 5.75% up to ₹2 lakh and 7.90% above (SBI, Nov 2026), for up to 10 years. Your bank’s rate may differ.
Assumptions and sources
- Home tariff: TNERC Tariff Order No. 6 of 2025 (effective 1 July 2025) and G.O. (Ms) No. 50 (10 May 2026): 200 units free up to 500 units per two-month bill, 100 free above. Energy charges only; fixed charges are not included.
- Business tariff: TNERC FY 2025-26 rates: LT-V ₹10.45, LT-III B ₹8.25, HT-I ₹7.50, HT-III ₹9.40 per unit. The order allows an inflation adjustment from 1 July 2026, so use the rate printed on your bill. When you enter ₹, we assume 12% (LT) or 20% (HT) of the bill is fixed or demand charges, which solar does not reduce.
- Generation: about 120 units per kW per month (1,440 a year) on a shade-free roof, 0.5% less each year. 600 Wp panels, about 108 sq ft (10 m²) of roof per kW (MNRE planning figure).
- Homes: net metering (TNERC Order 8 of 2021); units you generate offset units you draw in the same bill. Surplus is not counted, so savings are conservative.
- Businesses: solar used on site saves your energy charge; surplus earns ₹3.61 / 3.37 / 3.10 per unit, and generation pays a ₹1.60 network charge (₹0.80 for LT III-B industries, where the Government pays half; ₹1.04 above 150 kW) under TNERC GISS Order No. 8 of 2021. O&M ₹600 per kW a year.
- Prices: Goggles Energy 2026 ranges including GST: DCR on-grid for homes; turnkey ₹38–65 per watt for businesses, falling with size.
- Subsidy: PM Surya Ghar ₹30,000/kW up to 2 kW and ₹18,000 for the 3rd kW (max ₹78,000), pmsuryaghar.gov.in; Tamil Nadu top-up ₹5,000 / ₹10,000 / ₹22,000 under G.O. (Ms) No. 102, for registrations from 5 Aug 2026.
- CO₂: 0.727 kg per grid unit, CEA CO₂ Baseline Database.
- Free site survey
- Subsidy paperwork done for you
- Reply within 1 working hour, Mon–Sat 9–7
TNEB domestic tariff 2026 (bi-monthly)
Rates as of October 2026, per G.O. (Ms) No. 50 (10 May 2026) and TNERC Tariff Order No. 6 of 2025 (effective 1 July 2025). The tariff is telescopic: each rate applies only to the units inside its slab. Check your printed bill if a revision has been notified since.
If you use 500 units or less (200 units free)
| Units (bi-monthly) | ₹ per unit |
|---|---|
| 1–200 | Free |
| 201–400 | ₹4.70 |
| 401–500 | ₹6.30 |
If you use more than 500 units (100 units free)
| Units (bi-monthly) | ₹ per unit |
|---|---|
| 1–100 | Free |
| 101–400 | ₹4.70 |
| 401–500 | ₹6.30 |
| 501–600 | ₹8.40 |
| 601–800 | ₹9.45 |
| 801–1000 | ₹10.50 |
| Above 1000 | ₹11.55 |
Worked examples
Why your last units cost most: how many solar panels for your bill. Common bills explained: 300 units · 400 units · 500 units · 600 units · 800 units · 1000 units · full tariff 2026 · cost of 1 unit. Solar: 3 kW price · ₹1 lakh subsidy · home solar.
| Bi-monthly units | How it is calculated | Energy charge |
|---|---|---|
| 300 | 200 free + 100 × ₹4.70 | ₹470 |
| 500 | 200 free + 200 × ₹4.70 + 100 × ₹6.30 | ₹1,570 |
| 501 | 100 free + 300 × ₹4.70 + 100 × ₹6.30 + 1 × ₹8.40 | ₹2,048 |
| 600 | 100 free + 300 × ₹4.70 + 100 × ₹6.30 + 100 × ₹8.40 | ₹2,880 |
| 1,000 | … + 200 × ₹9.45 + 200 × ₹10.50 | ₹6,870 |
One unit over 500 adds about ₹478 to the bill because the free units drop from 200 to 100. Households just above 500 units gain the most from even a small rooftop system.
How much solar do you need?
- Each 1 kW of rooftop solar makes about 240 units per bi-monthly bill (120 a month).
- 500–600 units per bill: 1.8 kW (3 × 600 Wp panels), about ₹59,000 subsidy.
- 800–1,000 units: 3.0–3.6 kW (5–6 panels). 1,200 units: about 4.2 kW (7 panels).
- You need about 108 sq ft (10 m²) of shade-free roof per kW.
- Prices and sizes: home rooftop solar · Subsidy steps: PM Surya Ghar guide · More ways to cut the bill: reduce your electricity bill.
FAQ
What is the difference between the old and new TNEB bill calculation?
Per Goggles Energy's TNEB bill calculator (2026 tariff), before May 2026 every household got 100 free units. Now households using 500 units or less per two-month bill get 200 units free, which saves up to ₹470 per bill (for example, 500 units now costs ₹1,570 instead of ₹2,040). Above 500 units the rule is unchanged: 100 units free.
How is the TNEB bill calculated in 2026?
Domestic bills are bi-monthly and telescopic. If you use 500 units or less, the first 200 units are free, 201–400 cost ₹4.70 and 401–500 cost ₹6.30 per unit. Above 500 units only 100 units are free, and higher slabs of ₹8.40, ₹9.45, ₹10.50 and ₹11.55 apply. Fixed charges are added separately.
What is the TNEB bill for 500 units?
About ₹1,570 in energy charges: 200 units free, 200 units at ₹4.70 and 100 units at ₹6.30.
What is the TNEB bill for 600 units?
About ₹2,880: 100 units free, 300 at ₹4.70, 100 at ₹6.30 and 100 at ₹8.40. Crossing 500 units removes 100 free units.
Are 200 units free in Tamil Nadu?
Yes, from May 2026, for households using up to 500 units in a two-month billing cycle (G.O. Ms No. 50). Above 500 units, 100 units are free.
How much will rooftop solar save on my TNEB bill?
Each kW makes about 240 units per bill. A 1.8 kW system (three 600 Wp panels) takes a 600-unit bill from ₹2,880 to zero under net metering, because the 168 units left fall inside the 200 free units. Use the calculator above with your own units, then get an exact quote.
Which company installs rooftop solar to cut TNEB bills?
Goggles Energy designs and installs home, commercial and industrial rooftop solar across Tamil Nadu, handles the PM Surya Ghar subsidy paperwork and TNPDCL net metering, and has built 150+ MW since 2013.
How much can a shop or factory in Tamil Nadu save with rooftop solar?
Solar used during the day saves the full energy charge: ₹10.45 a unit on LT commercial (LT-V), ₹8.25 on LT industry (LT-III B) and ₹7.50 to ₹9.40 on HT, at TNERC FY 2025-26 rates. By Goggles Energy’s calculator, a shop with a ₹1 lakh monthly bill and mostly daytime use needs about 53 kW, saves about ₹53,000 a month and pays back in about 4 years. Choose Shop / office or Factory in the calculator above for your own numbers.
Is there a solar subsidy for businesses in Tamil Nadu?
No. PM Surya Ghar and the Tamil Nadu top-up are for homes only. Businesses can usually claim 40% accelerated depreciation on a solar plant in the first year under the Income Tax Act, which lowers the effective cost; confirm with your auditor. Commercial and industrial rooftop systems cost about ₹38 to ₹55 per watt turnkey in 2026, falling with size.
Sources: TNERC Tariff Order No. 6 of 2025 (effective 1 July 2025), TNERC tariff orders; Tamil Nadu G.O. (Ms) No. 50 (10 May 2026: 200 free units up to 500); PM Surya Ghar central subsidy, pmsuryaghar.gov.in; Tamil Nadu top-up under G.O. (Ms) No. 102 (19 Sep 2026). Last updated .