Tamil Nadu Net Metering (TANGEDCO) 2026: The Full Homeowner Guide

Tamil Nadu is a strong solar state on paper — decent irradiation, high tariffs, and one of India''s longest-running net metering policies (since 2014). In practice, TANGEDCO net metering has a reputation for being slower and paperwork-heavier than Gujarat or Karnataka. It''s still absolutely worth doing, but you need to know what you''re getting into.

Here''s the practical 2026 guide for Chennai, Coimbatore, Madurai, Salem, Trichy, and everywhere else in TN.

How TANGEDCO net metering works

Standard net metering setup: your solar exports surplus to the grid, a bi-directional meter tracks the two-way flow, and your monthly bill shows net consumption. TANGEDCO settles surplus units at the end of each financial year (March 31) — anything left over gets paid at the state''s power purchase cost, which is roughly one-third of what you pay for consumption. So oversizing is a bad idea.

Capacity limits in 2026:

• Residential (LT): up to 100% of sanctioned load, cap 10 kW
• Commercial (LT): up to sanctioned load
• HT commercial/industrial: up to 999 kW under net metering (larger goes to gross metering)

The application process — the honest version

Step 1: File the online application on TANGEDCO''s rooftop solar portal. Requires: sanctioned load copy, latest bill, roof photos, system design SLD (single-line diagram), installer registration.

Step 2: TANGEDCO reviews and issues technical feasibility approval (target 15 days; realistic 30-45 days depending on your section).

Step 3: You install the system. Your installer submits work completion certificate.

Step 4: TANGEDCO inspection. This is where TN loses time compared to other states. Officially 15 days after completion notification; often 60-90 days in Chennai/Coimbatore, longer in rural sections.

Step 5: Bi-directional meter installation. Usually 15-30 days after passing inspection.

Total realistic timeline: 90-150 days from application to active net metering. Faster if you choose a TANGEDCO-empanelled installer with strong local relationships in your section.

What Tamil Nadu homeowners get wrong

Choosing an installer without TANGEDCO empanelment. This is the #1 mistake. Only TANGEDCO-empanelled installers can file net metering applications. A random installer might charge less but you''ll be unable to claim subsidies or activate net metering. Ask for their empanelment certificate number and verify on the TANGEDCO portal before signing.

Not accounting for the settlement structure. Tamil Nadu carries surplus forward monthly, then settles annually in March at APPC (~₹3-4/unit). If you generate more than you consume across the year, you''re getting paid less than 40% of what your consumption tariff is. Size the system to your actual consumption, not aspirational usage.

Assuming the ₹78,000 subsidy applies automatically. The PM Surya Ghar subsidy is a central scheme that requires ALMM-listed panels and a specific application through the PM Surya Ghar portal (pmsuryaghar.gov.in), separate from TANGEDCO''s process. Your installer should file both. Verify.

Ignoring transformer capacity checks. In parts of Chennai and Coimbatore with older infrastructure, your local transformer may not have spare capacity to absorb solar export. TANGEDCO does a feasibility check for this at Step 2, but it can trigger a "transformer upgrade required" flag that adds ₹50,000-2 lakh and months of delay. Ask your installer to check transformer loading before you sign.

Real savings math for Tamil Nadu

Example: 3 kW residential system in Chennai or Coimbatore

• Typical monthly generation: 380-430 units
• TN residential tariff avoided: ₹6-9/unit (slab-dependent)
• Monthly bill saving: ₹2,500-3,800
• System cost after ₹78,000 PM Surya Ghar subsidy: ₹1.0-1.3 lakh
• Payback: 32-45 months

Coimbatore and Madurai typically see slightly better generation than Chennai due to less coastal humidity and cloud cover in monsoon. Chennai homeowners should specify salt-mist-certified panels (Tata Power Solar, Vikram Somera, Waaree salt-spray SKUs) given the coastal environment.

Tamil Nadu-specific things worth knowing

Time-of-day tariff proposals. TN has been discussing time-of-day tariffs for years. If they come into effect, net metering economics shift — solar export during peak-tariff hours (11am-3pm) becomes more valuable. Nothing to change today, but worth knowing.

Group net metering. TN allows housing society-level net metering. Chennai apartment complexes have started using this for common-area electricity offset. Ask your society''s facilities team if this is being considered.

Chennai coastal challenges. Salt-air corrosion is a genuine 5-8 year issue for panels near the coast. Non-salt-mist-certified panels degrade faster. Pay the small premium for certified SKUs.

Rural electricity co-operatives. Some parts of rural TN are served by co-operative societies rather than TANGEDCO directly. Net metering rules and processing may differ. Check your bill for the utility name.

Common questions

How long does TANGEDCO net metering really take in 2026?

90-150 days end-to-end for most sections. Chennai and Coimbatore central are on the faster end. Rural sections and areas with transformer upgrade requirements can extend to 180+ days.

What''s the max system size I can install under net metering in TN?

Residential: 10 kW cap or 100% of sanctioned load, whichever is lower. Commercial: up to sanctioned load. HT: up to 999 kW.

Is there a state subsidy on top of the PM Surya Ghar ₹78,000?

Tamil Nadu doesn''t currently have a systematic residential top-up like Gujarat''s SURYA Yojana. Occasional targeted schemes appear (particularly for low-income households). Ask your installer for current state programs.

Can I install solar on a rented house in TN?

Technically yes, but you need owner consent in writing for the net metering application. The bi-directional meter is registered against the property, not the tenant. Most tenants don''t do this because the investment stays with the house.

Bottom line

Tamil Nadu solar economics work — payback in 3-4 years, then 20+ years of near-free electricity. The catch is that TANGEDCO''s net metering process is slower and more paperwork-heavy than Gujarat or Karnataka. Choose an experienced empanelled installer, size the system to your actual consumption, and be patient with the timeline. Once it''s live, it works.