Quick Answer: TANGEDCO domestic tariff in 2026 has 8 progressive slabs — from ₹0 for the first 100 units (free) up to ₹7.60/unit above 1,000 units. The critical detail most people miss: Tamil Nadu uses non-telescopic (whole-slab) billing — crossing a slab boundary changes the rate applied to every unit, not just the excess. A household using 410 bi-monthly units pays ₹1,330, while one using 400 units pays only ₹870 — a ₹460 jump for just 10 extra units. Scroll down for the full slab table, real-world bill examples, and how solar eliminates this slab-jump penalty entirely.

Understanding your TANGEDCO electricity tariff is essential before evaluating whether solar makes financial sense for your home or business. Tamil Nadu's electricity pricing structure is complex — with progressive slabs for domestic consumers, separate tariff categories for commercial and industrial users, and additional charges that appear on your bill beyond the base energy rate. This guide breaks down every tariff category applicable in 2026, shows you exactly how your bill is calculated, and compares the cost of grid electricity against solar generation.

Domestic Tariff Slabs (LT2A — Single Phase, LT2B — Three Phase)

TANGEDCO's domestic tariff follows a telescopic slab structure — the more you consume, the higher the per-unit rate. This progressive pricing is designed to protect low-consumption households while recovering costs from higher-consumption users. As of the latest TNERC tariff order applicable in 2026:

Single Phase Domestic (LT2A) — Bi-Monthly Billing

Consumption Slab (units/bi-month)	Energy Charge per Unit	Fixed Charge per Bi-Month
0–100 units	Free (subsidy by TN Govt)	Nil
101–200 units	₹1.50 per unit (for all units)	₹50
201–400 units	₹2.00 per unit (for all units)	₹70
401–500 units	₹3.00 per unit (for all units)	₹100
501–600 units	₹4.00 per unit (for all units)	₹120
601–800 units	₹5.50 per unit (for all units)	₹150
801–1000 units	₹6.60 per unit (for all units)	₹200
Above 1000 units	₹7.60 per unit (for all units)	₹250

Note on 2025 tariff revision: TNERC Order No. 6 of 2025 (effective July 2025) approved higher unsubsidised rates. The Tamil Nadu government announced it will absorb this hike via subsidy for domestic consumers — so the effective rates consumers see on their bills remain as shown below. Commercial and industrial rates are not subsidised and reflect the revised order.

Critical note on slab application: Tamil Nadu uses a non-telescopic (whole-slab) billing method for domestic consumers. This means if your bi-monthly consumption is 450 units, the ₹3.00 rate applies to all 450 units, not just the units between 401 and 500. This creates sharp jumps in your bill when you cross slab boundaries.

Three Phase Domestic (LT2B)

Three-phase domestic consumers (typically homes with higher connected loads — multiple ACs, water heaters, etc.) follow the same slab structure as LT2A but with slightly higher fixed charges:

Consumption Slab (units/bi-month)	Energy Charge per Unit	Fixed Charge per Bi-Month
0–100 units	Free	Nil
101–200 units	₹1.50	₹70
201–400 units	₹2.00	₹100
401–500 units	₹3.00	₹130
501–600 units	₹4.00	₹150
601–800 units	₹5.50	₹190
801–1000 units	₹6.60	₹250
Above 1000 units	₹7.60	₹300

The Slab Jump Problem: Why It Matters for Solar

The whole-slab billing method creates a phenomenon where a small increase in consumption causes a disproportionate increase in your bill. Consider this example:

400 units consumed: 400 x ₹2.00 + ₹70 = ₹870
410 units consumed: 410 x ₹3.00 + ₹100 = ₹1,330

Just 10 extra units pushed the bill up by ₹460 — an effective rate of ₹46 per unit for those 10 additional units. This is precisely where a small solar system delivers outsized returns. Even a 1 kW solar system generating 120–140 units bi-monthly can keep you in a lower slab and save you far more than the raw per-unit value of the electricity generated.

Use our solar savings calculator to see exactly how much a solar system would save based on your current consumption slab.

Commercial Tariff Rates (LT3)

Commercial consumers — shops, offices, restaurants, hotels, hospitals — pay significantly higher tariffs than domestic consumers. TANGEDCO's commercial tariff does not have the progressive slab structure; instead, it is a flat rate with demand-based charges.

Tariff Component	Rate
Energy Charge	₹8.00–₹10.50 per unit
Fixed/Demand Charge	₹80–₹120 per kW of sanctioned demand per month
Fuel Cost Adjustment (FCA)	₹0.15–₹0.40 per unit (varies quarterly)
Power Factor Surcharge	Up to 2% penalty if PF < 0.9

Billing cycle: Commercial consumers are billed monthly (unlike domestic bi-monthly).

For a commercial establishment consuming 2,000 units per month with a 10 kW sanctioned demand, the monthly bill works out to approximately:

Energy charges: 2,000 x ₹9.00 = ₹18,000
Demand charges: 10 x ₹100 = ₹1,000
FCA: 2,000 x ₹0.25 = ₹500
Total: approximately ₹19,500 per month

At ₹9+ per unit effective rate, commercial solar with a generation cost of ₹2.50–₹3.50 per unit offers a 60–70% savings on electricity costs. This is why commercial rooftop solar has the fastest payback period of any consumer category.

Industrial Tariff Rates

Industrial consumers are categorised under multiple tariff codes depending on voltage level and connected load.

LT Industrial (LT4/LT5) — Low Tension Supply

Tariff Component	Rate
Energy Charge	₹5.75–₹6.50 per unit
Demand Charge	₹200–₹300 per kVA per month
FCA	₹0.15–₹0.40 per unit
Power Factor Penalty	1% surcharge per 0.01 drop below 0.9

HT Industrial (HT1/HT2) — High Tension Supply (11 kV / 33 kV)

Tariff Component	Rate
Energy Charge	₹5.50–₹6.75 per unit
Demand Charge	₹350–₹500 per kVA per month
FCA	As notified
Minimum Demand	90% of sanctioned demand
TOD Tariff (peak surcharge)	+25% during peak hours (6 AM–10 AM and 6 PM–10 PM)
TOD Tariff (off-peak rebate)	-5% during off-peak (10 PM–6 AM)

EHT Industrial (HT3) — Extra High Tension (66 kV / 110 kV)

Tariff Component	Rate
Energy Charge	₹5.00–₹6.00 per unit
Demand Charge	₹400–₹550 per kVA per month
Contract Demand	Minimum 1 MVA
RPO Compliance	Mandatory renewable purchase obligation

Industrial solar insight: For HT/EHT consumers paying ₹6+ per unit plus demand charges, rooftop and open-access solar installations offer payback periods of 3–4 years. The time-of-day (TOD) peak surcharge makes solar especially valuable since solar generation peaks during daytime hours, reducing peak-rate consumption. Contact us for industrial solar feasibility analysis.

Agricultural Tariff

Tamil Nadu provides free electricity to agricultural pump set consumers under a long-standing state subsidy:

Category	Tariff
Agricultural pump sets (LT6)	Free (government subsidised)
Agricultural services (HT4)	Subsidised — ₹1.50–₹2.00 per unit

While agricultural consumers receive free electricity, the supply is often restricted to specific hours (typically 7–9 hours per day), and power quality on agricultural feeders can be poor. Some progressive farmers are installing solar pump systems to gain independence from restricted supply schedules, especially for precision irrigation that requires on-demand power.

How to Calculate Your TANGEDCO EB Bill: Step by Step

Let us walk through a complete domestic bill calculation with a real example.

Scenario: A household in Coimbatore consumes 550 units in a bi-monthly billing period.

Step 1: Identify the Applicable Slab

550 units falls in the 501–600 units slab with an energy charge of ₹4.00 per unit.

Step 2: Calculate Energy Charges

Since Tamil Nadu uses whole-slab billing, the ₹4.00 rate applies to all 550 units: Energy charge = 550 x ₹4.00 = ₹2,200

Step 3: Add Fixed Charges

For the 501–600 slab, the bi-monthly fixed charge is ₹120.

Step 4: Add Fuel Cost Adjustment (FCA)

FCA is a variable charge that TNERC revises quarterly based on TANGEDCO's fuel procurement costs. Current FCA rate: approximately ₹0.20 per unit. FCA = 550 x ₹0.20 = ₹110

Step 5: Add Tax

Electricity duty of 5% applies to energy charges in Tamil Nadu. Tax = ₹2,200 x 0.05 = ₹110

Step 6: Total Bill

Component	Amount
Energy charges (550 x ₹4.00)	₹2,200
Fixed charges	₹120
Fuel cost adjustment	₹110
Electricity duty (5%)	₹110
Total bi-monthly bill	₹2,540
Effective rate per unit	₹4.62

What If Solar Reduced Consumption to 300 Units?

With a 2–3 kW solar system generating approximately 250 units bi-monthly, consumption drops to 300 units — landing in the 201–400 slab at ₹2.00 per unit:

Component	Amount
Energy charges (300 x ₹2.00)	₹600
Fixed charges	₹70
FCA (300 x ₹0.20)	₹60
Electricity duty (5%)	₹30
Total bi-monthly bill	₹760

Savings per bi-month: ₹1,780 (₹2,540 minus ₹760). That is ₹10,680 saved per year — and this does not account for further savings from net metering export credits. Check your specific savings with our solar calculator.

Domestic consumers can reduce upfront cost further through the PM Surya Ghar subsidy of up to ₹78,000 for systems up to 3 kW, or by financing through a solar loan at 8–9% interest — making the monthly EMI lower than the EB bill savings from day one.

Fuel Cost Adjustment Charges (FCA)

FCA is one of the least understood components of your electricity bill. TNERC permits TANGEDCO to pass through variations in fuel costs (coal, gas, purchased power costs) to consumers through a quarterly-revised surcharge.

FCA is calculated per unit consumed and appears as a separate line item on your bill
The rate varies between ₹0.10 and ₹0.50 per unit depending on TANGEDCO's fuel cost position
FCA applies to all consumer categories
TNERC publishes FCA orders quarterly on tnerc.gov.in

FCA effectively increases your tariff by ₹0.10–₹0.50 beyond the base rate. Solar-generated units are not subject to FCA, which is an additional hidden saving from solar.

Monthly vs Bi-Monthly Billing

TANGEDCO bills different consumer categories on different cycles:

Consumer Category	Billing Cycle
Domestic (LT2A, LT2B)	Bi-monthly (every 2 months)
Commercial (LT3)	Monthly
Industrial (LT4, LT5)	Monthly
HT consumers	Monthly
Agricultural (LT6)	No charge — free supply

For domestic consumers, the bi-monthly cycle means your slab is evaluated based on two months of cumulative consumption. A household using 250 units per month will be billed for 500 units bi-monthly, placing them in the 401–500 slab at ₹3.00 per unit. Monthly billing would have kept each month's 250 units in the 201–400 slab at ₹2.00 per unit. This is a structural disadvantage of bi-monthly billing that solar directly addresses by reducing cumulative consumption.

EB Bill Cost vs Solar Cost per Unit: The Comparison

The fundamental question: is solar cheaper than grid electricity?

Parameter	TANGEDCO Grid	Rooftop Solar
Cost per unit (domestic, 500+ units)	₹4.00–₹7.60	₹2.00–₹3.00 (levelised over 25 years)
Cost per unit (commercial)	₹6.35–₹7.50	₹2.50–₹3.50
Cost per unit (industrial HT)	₹5.50–₹6.75	₹2.50–₹3.50
Annual escalation	3–5% (tariff revisions)	0% (sunlight is free)
Fuel cost adjustment	₹0.10–₹0.50 additional	None
25-year cost trend	Rising	Fixed at installation cost

Over a 25-year system life, the gap widens dramatically. A household paying ₹5.50 per unit today will likely pay ₹9–12 per unit by 2040 at historical tariff escalation rates, while their solar cost per unit remains fixed at the day-of-installation rate. Note: the ₹2.00–₹3.00 solar cost above factors in the 5% concessional GST on panels and installation and assumes the PM Surya Ghar subsidy for eligible domestic systems.

How Tariff Hikes Affect Your Long-Term Solar Savings

TNERC has revised TANGEDCO tariffs multiple times over the past decade, and the trend is consistently upward. Each tariff revision increases the value of solar electricity you generate:

2014 tariff revision: First major increase after a long freeze
2017 revision: 10–15% increase across categories
2022 tariff order: Significant restructuring of domestic slabs
2024–2025 FCA increases: Passed through rising coal costs to consumers
2026 expected: Further revisions under discussion at TNERC

Every future tariff increase makes your existing solar system more valuable because your generation cost was locked in at installation. A system installed in 2026 at ₹2.50 per unit levelised cost will save progressively more every year as grid tariffs rise.

Want to know exactly how much you would save? Use the Tristar solar savings calculator with your actual TANGEDCO consumer number, or contact our team for a personalised savings analysis based on your tariff category and consumption pattern. We serve homeowners and businesses across Tamil Nadu with customised solar solutions designed to maximise your tariff savings.

TANGEDCO Electricity Tariff Rates 2026: Complete Slab-Wise Guide