TNEB tariff hike 2026 — full slab breakdown, solar impact, action plan

**Order summary:** TNERC (Tamil Nadu Electricity Regulatory Commission) 26 March 2026 order la domestic tariff 8-12% hike announce pannirichu, effective April 1, 2026. Commercial LT 6% up, HT industrial 4% up. Kaarnam — TANGEDCO ₹12,800 crore revenue gap + coal price volatility + green energy obligation surcharge.

**Domestic slab new rates (per unit, effective April 2026):** 0-100 units → ₹0 (free continues); 101-200 → ₹3.25 (was ₹3.00); 201-400 → ₹5.75 (was ₹5.25); 401-500 → ₹7.25 (was ₹6.75); 501+ → ₹8.50 (was ₹7.75). Plus fixed charge ₹75/month unchanged.

**Effective bill impact (real examples):** 350 units/month household — old bill ₹1,300, new bill ₹1,455 (+12%). 550 units/month — old ₹3,375, new ₹3,725 (+10%). 750 units/month — old ₹5,325, new ₹5,850 (+10%). Kids + 1.5 ton AC + geyser homes 500+ units common — hike bite maximum.

**Commercial LT rate:** LT-CT tariff ₹8.20/unit (was ₹7.75) + demand charge ₹75/kW (was ₹70). Small shops, offices, restaurants — monthly bill ₹8k → ₹8.6k typical 7% jump.

**HT industrial (HT-IIA):** ₹9.50/unit (was ₹9.10) + demand charge ₹450/kVA (was ₹425). ToD (Time of Day) surcharge unchanged — peak hours +₹1.50/unit, off-peak -₹0.75.

**Solar customer impact — offset value up:** solar generation savings TNEB tariff-avoided. Tariff up = savings up. Example: 3 kW system 12 units/day = 360 units/month generation. Pre-hike: ~₹2,600 saved. Post-hike: ~₹2,950 saved. 13% more value from same system.

**Payback re-calculation (residential 3 kW):** system cost ₹1.85L post-subsidy, monthly savings ₹2,950 = ₹35,400/year. Payback 5.2 years → 4.6 years (12% faster). 25-year IRR 18% → 20%.

**Commercial (10 kW system):** cost ₹5.6L post-depreciation, monthly savings ₹11,500 → ₹13,300 post-hike. Payback 3.8 → 3.2 years.

**Net metering rate:** TN 1:1 export = import maintained (rare in India — most states shift to gross metering). Annual settlement excess unit credit rate ₹2.75/unit (was ₹2.60) — slight positive. Small system oversize buffer OK, but 15% surplus target padhi.

**High-consumption houses ku recommendation:** 500+ units/month → 3-5 kW solar strong ROI. Bill zero possible. AC-heavy Chennai/Coimbatore homes → 5 kW default. Farm houses + AC + pump → 7-10 kW hybrid with battery.

**Business owner recommendation:** commercial tariff + demand charge combined la 10 kW+ system 3-year payback zone la irukku. MSME AD depreciation year 1 la 40% tax off — investment effectively 25% subsidized via IT saving.

**Timing decision — install before or wait:** subsidy revision late 2026 risk + panel price stable-to-up trend + tariff hike compounding = waiting cost ₹8,000-15,000/quarter for typical 3-5 kW customer. Lock now sensible.

**Long-term view:** TNEB tariff historically 6-8% CAGR over 10 years. Solar generation cost ₹0 after payback. 25-year power hedging = solar's real value beyond just today's ROI.

**Action for existing solar owners:** production report review pannunga — 3-5 year systems la dust degradation 8-12% common. Cleaning + panel angle adjust panna 5-8% output recover aagum, tariff-hike-post generation value ₹300-600/month extra.