Solar net metering in Tamil Nadu: how it works with TNPDCL
Net metering is what turns your rooftop solar into lower electricity bills. Here is how it works in Tamil Nadu, who qualifies, and the steps from application to a working net meter.
What is net metering?
Net metering lets your solar system work together with the grid. During the day your panels power your home first, and any extra units flow out to the grid. At night or on cloudy days you draw units from the grid as usual.
TNPDCL replaces your existing meter with a bi-directional net meter that records both directions. Your bill is then based on the units you imported minus the units you exported. If you export more than you use in a billing cycle, the extra units are carried forward to your next bill.
Who can get net metering in Tamil Nadu?
- Homes (domestic connections) can get net metering for a system up to their sanctioned load.
- Apartment common areas: the Tamil Nadu Electricity Regulatory Commission has directed that net metering should also be available for the common-services tariff used by residential associations.
- Shops, offices and other low-tension connections generally use a "net feed-in" arrangement, where exported units are credited at a set tariff instead of being netted off unit for unit.
There is also a limit on how much rooftop solar can connect to one local transformer, which TNPDCL checks during feasibility approval.
The process, step by step
- Register on the PM Surya Ghar national portal if you want the subsidy. Subsidy projects start here.
- The application reaches TNPDCL through the Tamil Nadu rooftop solar portal, which generates a TNPDCL reference number for your file.
- Feasibility check: TNPDCL confirms your sanctioned load and the local transformer capacity.
- Installation by your installer, following the approved design.
- Inspection and net meter: officials from your area's TNPDCL office inspect the system and fit the net meter.
- Commissioning: after approval, the system is switched on and starts exporting.
Important: never switch on a grid-connected system before TNPDCL has inspected it and fitted the net meter. Doing so can delay approval and the subsidy.
Documents usually required
- Latest electricity bill showing your service connection number
- Identity proof of the person named on the connection
- Proof of ownership or permission to use the roof
- System details: panel and inverter specifications and the single-line diagram, prepared by the installer
- Installer's work completion report and test results at the inspection stage
VM Skyline Solar prepares the technical documents and coordinates the TNPDCL inspection for every installation we do.
What happens during power cuts?
A grid-connected (on-grid) system switches off automatically when the grid supply fails. This is a safety rule so that electricity linemen repairing the lines are not put at risk. If you need power during cuts, a hybrid system with batteries keeps selected loads running.
Frequently asked questions
Does net metering cost anything?
There is a small application process through TNPDCL and the net meter is fitted as part of the connection. Your installer can tell you the current charges for your connection before you apply.
Can my solar system be bigger than my sanctioned load?
Not for a home on net metering. If you need a bigger system, apply for a load increase with TNPDCL first.
What happens to extra units I export?
They are adjusted against the units you import, and surplus units are carried forward to the next billing cycle.
Does the old TANGEDCO name still matter?
Electricity distribution in Tamil Nadu is now handled by TNPDCL, but you may still see the TANGEDCO or TNEB name on older forms, bills and portals. They refer to the same process.