Solar for Tamil Nadu's mills, food plants, cold stores and warehouses
On a Tamil Nadu bill, a solar unit you use on site is worth three to five times one you export. So we size every plant to how your industry actually uses power, then build, connect and maintain it.
Since 2013150+ MW installedClients include Aachi Masala, Kanam Latex and Inter Mode International
Your load against the sun, over 24 hours
Pick your industryThree shifts keep the load above the solar curve all day, so the whole output is used on site.
Read the textile mill sectionIllustrative daily profiles. Your own 15-minute meter data sets the real size.
Why we size to your load, not your roof
Tamil Nadu bills solar on net feed-in for businesses. Every unit you use on site saves your full energy charge, less a small network charge. Every unit you export is credited at a fixed feed-in rate. The gap decides how big your plant should be.
Used on site (HT-I)
₹6.46/unit
Exported (151–999 kW)
₹2.06/unit
HT-I energy charge ₹7.50, or feed-in ₹3.10, each less the ₹1.04 network charge. Full table below.
Solar for textile mills
Load patternThree shifts, 24×7Mostly HT supply
Spinning, weaving and processing mills run around the clock, so every unit a rooftop plant makes in daylight is used on site and saves the HT-I energy charge of ₹7.50 a unit, less the ₹1.04 network charge.
Solar does not lower the ₹608/kVA demand charge, so we size the plant to your daytime base load, not your peak. Above 1 MW, the plant runs in parallel with the grid through a reverse-power relay.
Solar for garment and apparel units
Load patternDay shiftSewing, pressing, compressors
Sewing floors, steam irons, compressors and lighting run through the day shift, so your load follows the solar curve closely and almost every unit is used on site.
Many global apparel brands now ask suppliers to report and cut emissions from the electricity they buy. Metered solar generation on your own roof is the most direct evidence you can show an auditor.
Solar for spice and food processing
Load patternDay + eveningHeavy motor loads
Pulverisers, roasters, blenders and packing lines are heavy motor loads that peak in working hours, when solar output is highest, so most of the plant's output is used as it is made.
Food plants also need a roof that stays sealed. We design the mounting and walkways so the sheets stay watertight and panels are cleaned without anyone stepping on them, with a cleaning plan that allows for grinding dust settling on the glass.
Solar for manufacturing plants
Load patternDay shift, some eveningLT III-B or HT-I
Machine shops, moulding, curing and laminating lines are daytime-heavy loads. Each solar unit used on site is worth about ₹6.50–6.65 after network charges, against about ₹2 for a unit exported.
If you buy the plant, it qualifies for 40% accelerated depreciation in its first year, which lowers your tax and shortens the payback. Your CA can confirm the benefit for your company.
Solar for cold storage
Load pattern24×7 refrigerationPeaks in afternoon heat
Refrigeration compressors run 24 hours a day, and their load rises in the afternoon heat, when solar output is highest. A well-sized plant is used almost entirely on site.
A grid-tied plant switches off during a power cut, as safety rules require. If you need backup, a hybrid inverter and battery can carry your critical compressors and cut diesel generator hours.
Solar for logistics parks and transport hubs
Load patternDay, with evening docksOffices, docks, EV fleets
Offices, dock lighting, dock levellers and EV chargers for delivery fleets draw most of their power in the day. Charging the fleet at midday puts even more of the solar output to use.
Solar canopies over parking and loading bays add generation without using the warehouse roof, and shade vehicles and crews while they wait.
Solar for warehouses
Load patternLow, daytimeLighting, forklift charging, offices
Warehouses have the biggest roofs and often the smallest daytime load. Surplus exported to the grid earns only ₹3.10–3.61 a unit before network charges, so we size the plant to what the building uses, not to the roof area.
We check the roof sheets and purlins before anything else. A plant built to last 25 years needs a roof that will last as long.
What a solar unit is worth on a Tamil Nadu bill
Businesses in Tamil Nadu use net feed-in. Solar you use on site saves your energy charge, less a network charge on every unit generated. The demand or fixed charge on your bill stays the same.
| Tariff | Who it covers | Energy charge (₹/unit) | Demand or fixed charge | Network charge (₹/kWh) | Saved per unit used (₹) |
|---|---|---|---|---|---|
| HT-I | Industries, factories, IT services | 7.50 | ₹608/kVA a month | 1.04 | 6.46 |
| HT-III | Commercial and miscellaneous | 9.40 | ₹608/kVA a month | 1.04 | 8.36 |
| LT III-B | Industries, IT services | 8.25₹8.00 payable up to 50 kW | ₹168/kW (0–50 kW) or ₹330/kW (50–112 kW) per two months; ₹608/kW a month above 112 kW | 1.60 | 6.65 |
| LT-V | Commercial and general purpose | 10.45 | ₹220/kW (0–50 kW) or ₹664/kW (50–112 kW) per two months; ₹608/kW a month above 112 kW | 1.60 | 8.85 |
| Plant size | Consumer | Feed-in tariff (₹/unit) | Network charge (₹/kWh) | Net value (₹) |
|---|---|---|---|---|
| Up to 10 kW | LT, other than homes | 3.61 | 1.60 | 2.01 |
| 11–150 kW | LT, other than homes | 3.37 | 1.60 | 1.77 |
| 151–999 kW | HT, net feed-in | 3.10 | 1.04 | 2.06 |
Size to daytime use
A unit used on site saves ₹6.46–8.85. An exported unit nets about ₹2. Size the plant to what you use in daylight.
The demand charge stays
HT demand is billed on your highest recorded kVA, which can fall in a cloudy hour or after sunset. Solar cuts the units you buy, not that charge.
Above 1 MW, no export
Plants above 1 MW run in parallel operation with a reverse-power relay, so the whole output must be used on site.
Sources: TNERC tariff order No. 6 of 2025, rates effective 1 July 2025; TANGEDCO summary of TNERC's GISS order No. 8 of 2021. "Saved per unit" assumes the network charge applies to all solar generation, as the order states for LT consumers. Tariffs are revised each year, so check against your latest bill.
Work out your plant size with the TNEB bill calculatorFour ways to pay for it
- CAPEX
- You buy the plant, keep every unit it makes and claim 40% accelerated depreciation.
- RESCO / PPA
- A developer builds and owns the plant. You pay a fixed rate per unit, with no capital outlay.
- BOOT
- Like RESCO, but the plant becomes yours at the end of the agreed term.
- Open access
- For more power than your roof can give: buy solar from an off-site plant through the grid.
Questions plant heads ask
Does rooftop solar reduce the demand charge on an HT bill?
Usually not. The demand charge, ₹608/kVA a month for HT-I, is billed on your highest recorded demand, which can fall in a cloudy hour or after sunset. Solar cuts the energy units you buy, which is why we size it to your daytime base load.
What are the network charges for rooftop solar in Tamil Nadu?
Under TNERC's GISS order, LT consumers other than homes pay ₹1.60 per kWh on total solar generation. HT consumers with 151–999 kW plants on net feed-in pay ₹1.04 per kWh. Gross metering has no network charge. Homes pay 20% or 75% of ₹1.60, depending on plant size.
What happens to surplus solar a factory exports?
Under net feed-in, exported units are credited at the feed-in tariff: ₹3.61 a unit up to 10 kW, ₹3.37 for 11–150 kW and ₹3.10 for 151–999 kW. Imported units are billed at your full tariff, so a unit used on site is worth three to five times an exported one.
Can a factory install more than 1 MW of rooftop solar?
Yes. TANGEDCO approves plants above 1 MW in parallel operation, with a reverse-power relay so no power flows back to the grid. The plant must stay within your daytime load. For more capacity than your roof or load allows, open access is the usual route.
Is there a subsidy for industrial rooftop solar?
The PM Surya Ghar subsidy is for homes only. A business that buys its plant can claim 40% accelerated depreciation in the first year, which lowers tax and shortens the payback. Your CA can confirm how it applies to your company.
Will solar keep my cold storage running during a power cut?
Not on its own. A grid-tied plant shuts down when the grid fails, so it cannot feed lines that crews may be working on. To keep compressors running, add a hybrid inverter and battery sized for your critical load, with the diesel generator as the last resort.
Get a free site visit for your plant
An engineer reviews your EB bill and roof, then sizes the plant to your load. We reply within one working hour, Monday to Saturday, 9 am to 7 pm.
- Plant size from your daytime load, not your roof area
- Savings worked out on your own tariff and network charge
- CAPEX, RESCO or open-access options side by side
Prefer to call? +91 77081 08158