TN & PONDICHERRY
Commercial Solar Calculator for Tamil Nadu & Puducherry
Estimate Your Commercial Solar Cost & Savings
A bill-based estimate using current commercial energy tariffs, optional GST input tax credit, optional depreciation tax benefit and a conservative Tamil Nadu solar network-charge setting.
Your Location
Average Monthly Bill
Puducherry model: NDS-I Commercial, above 200 units/month.
Average Electricity Bill
₹1,00,000 /month
Energy-equivalent consumption
0 units
Energy tariff used
₹0/unit
Regulatory surcharge used
Not applied
Solar network-charge reference
₹0/kWh
This is a bill-based estimate. Fixed / demand charges are not assumed to disappear after installing solar, so final sizing should be checked against the actual 12-month energy-consumption data and sanctioned demand.
Recommended System • Approximation
0 kW
Indicative on-grid commercial solar capacity based on the selected tariff and average bill.
Indicative Roof Area
0 sq.ft
Indicative EPC Invoice Cost (₹40,000 / kW quote assumption)
₹0
Embedded GST (13.8% blended assumption)
₹0
Pre-GST EPC Value
₹0
GST Input Tax Credit (if selected & eligible)
- ₹0
Estimated Depreciation Tax Benefit (first 3 years)
- ₹0
Effective Project Cost After Selected Tax Benefits
₹0
₹0
Year-1 Electricity Savings
0.0 Yrs
Estimated Simple Payback
₹0
25-Year Electricity Savings*
Data assumptions as of September 2026.
Tamil Nadu uses LT-V ₹10.45/kWh for commercial/general-purpose consumption above 100 units, or HT-III ₹9.40/kWh when selected. The Tamil Nadu network-charge toggle uses the last published TNERC FY 2025-26 reference rates of ₹1.60/kWh for LT and ₹1.04/kWh for HT; legal applicability to rooftop-solar consumers remains disputed, so the setting is user-adjustable. Puducherry uses FY 2026-27 NDS-I commercial tariff of ₹8.11/kVAh above 200 units and a 10% regulatory surcharge; this model applies that surcharge only to the avoidable energy component, not to fixed/demand charges. Solar sizing assumes 1,550 kWh/kWp/year, 90% target energy offset, 100 sq.ft/kW indicative roof area, and 0.5% annual generation degradation. The ₹40,000/kW EPC figure is treated as a GST-inclusive project-cost assumption, not a regulated tariff. The 13.8% GST figure assumes a 70:30 solar EPC valuation with 12% GST on the goods portion and 18% on the service portion. GST ITC and depreciation are not automatic and are therefore opt-in. Fixed/demand charges, electricity duty, FPPCA or other variable levies, export-credit differences, financing cost, O&M, inverter replacement, downtime and future tariff escalation are excluded. Actual feasibility, system size, savings and tax treatment must be validated from the consumer's bills, sanctioned/contracted demand, daytime load profile, roof survey, applicable metering arrangement and tax position.