TANGEDCO Net Metering: Application, Meters and Billing
Net metering lets a rooftop solar system export surplus power to the TANGEDCO grid and receive credit against consumption. The application is made to TANGEDCO, which assesses feasibility, approves the connection and installs the metering. Tamil Nadu requires two meters: a bi-directional net meter and a separate solar generation meter. Domestic consumers up to 10 kW receive one-for-one credit, settled on a bi-monthly billing cycle.
One thing worth knowing upfront: TNERC regulations require TANGEDCO to process a complete application within 30 days, and there is a formal escalation route if it does not. Almost nobody is told this.
What it does
Why your system needs a net meter
Without a net meter, an ordinary uni-directional meter can record exported solar power as though it were consumption, so a household can be billed for electricity it gave away. A bi-directional net meter records import and export separately, and TANGEDCO bills on the difference. This is the step that makes a rooftop system financially complete, and until it is done the system is generating without you receiving the benefit.
Without a net meter
One direction, counted once
Export can register as consumption. You are billed for units you gave away.
With a bi-directional meter
Import and export, counted separately
TANGEDCO bills the difference, so every exported unit is credited.
This page is about the TANGEDCO application itself, which is a separate process from the subsidy with its own approvals, timeline and escalation route. For how an on-grid system behaves through the day, see on-grid solar systems in Chennai. For the money, see solar subsidy in Tamil Nadu.
The PM Surya Ghar subsidyEligibility
Who is eligible, and how big
Any TANGEDCO consumer with a valid service connection and suitable shade-free roof area can apply for net metering, subject to one governing rule. For domestic consumers, systems up to 10 kW fall under net metering with one-for-one credit, and larger domestic systems move to net feed-in, where exports earn a rate below the retail tariff.
The one governing rule
System capacity ≤ sanctioned load
Everything else in the table below follows from this one line. Check it on your bill before you size anything.
Sanctioned load appears on your TANGEDCO bill in kilowatts. If you cannot find it, the section office will confirm it against your service number.
Two things to settle before you apply
The connection must be in the applicant's name
Many Chennai homes still have it in a parent's or previous owner's name. Fix this at the section office before applying.
Sanctioned load must support the system
If it does not, file the enhancement in parallel with the net metering application rather than afterwards.
One simplification in Tamil Nadu's favour: the state has a single distribution utility, so there is no question about which DISCOM serves your address, unlike states with multiple licensees.
The process
How to apply for TANGEDCO net metering
The net metering application is made to TANGEDCO through its rooftop portal, alongside the PM Surya Ghar application on the national portal where a subsidy is being claimed. TANGEDCO assesses feasibility, issues approval, and after installation carries out an inspection and installs the metering. Feasibility is waived for applications up to 3 kW, and carried out by TANGEDCO for larger systems.
Where applications typically stall: at feasibility, when the proposed capacity exceeds the sanctioned load, and at metering, when the connection work required was not filed in parallel. Both are avoidable at the survey stage. The documents you will need are listed separately.
The strongest thing on this page
What to do if TANGEDCO is slow
TNERC regulations require TANGEDCO to process a complete net metering application within 30 days of receiving it. A delay beyond that period is a regulatory breach rather than simply an inconvenience, and consumers have a formal escalation route through the Consumer Grievance Redressal Forum. Most consumers are unaware of this and simply wait.
Where does your application stand?
Your position
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What to do, in order
01
Confirm your application was complete
The 30-day clock runs from a complete application. A missing document restarts the practical delay and weakens any complaint. Check what was submitted before escalating.
02
Follow up at the section office in writing
Verbal follow-up leaves no record. A written follow-up, with the application reference and date, creates one and frequently resolves matters on its own.
03
Escalate through the consumer grievance channel
If the delay continues past the regulatory period, the Consumer Grievance Redressal Forum is the formal route. Escalation is not an aggressive act; it is the mechanism the regulations provide, and it is effective.
04
Keep documentation
Application date, acknowledgement, correspondence and the readiness report. A complaint supported by dated records moves considerably faster than one without.
What we do for our customers
We file the application, follow it at the section office, and escalate where the timeline is exceeded. Chasing a DISCOM is unfamiliar and uncomfortable for most homeowners, and it is exactly the part of the job an installer should be doing.
Metering
Why Tamil Nadu requires two meters
A net-metered system in Tamil Nadu requires a bi-directional net meter, which replaces the existing meter and records import and export separately, and a separate solar generation meter, which records total output from the array regardless of whether it was consumed or exported. Quotations accounting for only one meter are incomplete, and the second meter is a common source of disputes late in a project.
Meter 1 of 2
Bi-directional net meter
Replaces the existing meter and records units imported from and exported to the grid.
Determines your bill.
Meter 2 of 2
Solar generation meter
Records total output from the array, consumed or exported.
Shows the system's true output, independently of your consumption.
Why the generation meter is useful to you, not just to TANGEDCO
Your net meter only shows the difference between import and export. If you consume most of what you generate, the net meter shows very little export even though the system is working perfectly. The generation meter is the authoritative record of what the system actually produced, and it is what you check if you suspect underperformance.
Ask whether both meters are inside your quotation. They should be.
Settlement
Bi-monthly billing, credits and annual settlement
TANGEDCO reads domestic meters on a bi-monthly cycle. Within each cycle, units exported are credited against units imported, and any surplus carries forward as credit to the next cycle. At the annual settlement, credit still unused is compensated at a rate fixed by TNERC, which is lower than the retail tariff you pay on imports.
How a credit travels
Within the cycle
Exports offset imports one-for-one on the bill.
At cycle end
Any surplus banks forward as credit to the next cycle.
At year end
Credit still unused is paid at the TNERC rate — below retail.
A well-sized system
Typically produces surplus in the bright months and draws from banked credit through the northeast monsoon, so the credits balance out across the year.
Surplus that survives to annual settlement is worth less
Than surplus consumed or offset within the year, because the settlement rate sits below retail.
This is the reason not to oversize
Capacity that consistently exports more than it offsets is being paid for at full price and compensated at a lower one.
The practical conclusion
Size the system against twelve months of your own consumption. That is the sizing rule that runs through every page on this site, and net metering settlement is the reason for it.
After commissioning
What your electricity bill looks like once solar is live
After net metering is commissioned, your TANGEDCO bill shows units imported and units exported separately, with the charge calculated on the net difference and any surplus carried forward as credit. Fixed charges continue to appear regardless of solar generation, because solar reduces the units you are billed for rather than the standing charges on the connection.
Solar reduces this
Energy charge on net units
Billed on import minus export, so a good cycle can cut this to almost nothing.
Solar does not touch this
Fixed and standing charges
Meter rent, fixed charges and taxes on the connection continue every cycle.
Three things that surprise people on the first bill
01
The bill is not zero, even in a good month
Fixed charges remain, and any consumption beyond what solar offset is still billed. A large reduction is the realistic expectation, not elimination.
02
Exported units are not a cash payment
They are credit against consumption within the settlement framework, not money paid to you each cycle.
03
The first bill after commissioning can look odd
It often covers a partial period, spanning before and after the meter change. The second full cycle is the one to judge the system by.
Compare against your generation meter. If the numbers do not make sense, the generation meter tells you what the system produced, independently of what the net meter says about import and export. That is the starting point for any query.
Specific to Tamil Nadu
How solar interacts with Tamil Nadu's free unit allowance
Tamil Nadu provides a free-unit allowance to domestic consumers, and the way that allowance interacts with net metering credits is a reasonable question for any household considering rooftop solar. Consumers currently receiving free units should confirm with TANGEDCO how the calculation applies to their connection once solar is commissioned, since the treatment can differ from that of a standard metered consumer.
Where solar pays hardest
By billed consumption per bi-monthly cycle, not total consumption.
Within the free allowance
Weak case
Above the allowance, modest use
Worth modelling
Above 500 units a cycle
Strongest case
Higher slabs are the units solar displaces first, which is why the same system pays back faster on a bigger bill.
Why this matters for sizing
A household consuming well within the free-unit allowance has relatively little billed consumption for solar to displace, which lengthens payback. A household consuming above the threshold, particularly above 500 units per bi-monthly cycle, is paying higher slab rates on a large volume of units, and those are exactly the units solar displaces first.
What we do
We check your consumption pattern and slab position against twelve months of bills at the survey, and we tell you plainly if your bill is low enough that solar will take a long time to pay back. Some households are better served waiting, and we would rather say so.
Avoidable
Five common causes of delay
All five are identifiable at a proper site survey, which is why the survey matters more than most people assume.
We file it, we chase it
Get the net metering filed and followed
Blues Renewables files the TANGEDCO net metering application, checks your connection name and sanctioned load at the survey, files any load enhancement or phase conversion in parallel rather than afterwards, attends the inspection, and follows the application at the section office through to both meters being installed. Where the regulatory timeline is exceeded, we escalate.
Common questions
TANGEDCO net metering, common questions
TNERC regulations require a complete application to be processed within 30 days. In practice, urban Chennai commonly takes four to eight weeks from application to meters installed, with delays usually caused by sanctioned load issues or connection work filed late. Where the regulatory period is exceeded, the Consumer Grievance Redressal Forum is the formal escalation route.
First confirm the application was complete, since the regulatory period runs from a complete submission. Then follow up at the section office in writing rather than verbally, keeping the reference and dates. If the delay continues beyond the regulatory period, escalate through the consumer grievance channel. Documented, dated records make a complaint move considerably faster.
The feasibility process is waived for applications up to 3 kW. Above 3 kW, TANGEDCO carries out the feasibility assessment, examining the connection, sanctioned load and loading on the local distribution transformer.
A bi-directional net meter records import and export and determines your bill. A separate solar generation meter records total output from the array regardless of consumption, which is the authoritative record of what the system actually produced. Quotations accounting for only one meter are incomplete.
No. System capacity cannot exceed the sanctioned load on the connection, and this is the most common reason applications stall. If your sanctioned load is lower than the system you want, the enhancement should be filed alongside the net metering application rather than after it is rejected.
On a bi-monthly billing cycle, units exported are credited against units imported and any surplus carries forward. At the annual settlement, credit still unused is compensated at a rate fixed by TNERC, which is lower than the retail tariff. This is why oversizing a system does not pay.
Usually not, even in a good month. Fixed charges continue regardless of generation, and any consumption beyond what solar offset is still billed. A substantial reduction is the realistic expectation. Solar reduces the units you are billed for, not the standing charges on the connection.
Within the cycle, exported units are credited against imported units rather than paid as cash. Surplus carries forward as credit. Only credit remaining at the annual settlement is compensated, at a rate below the retail tariff.
Confirm the treatment with TANGEDCO for your specific connection, since the calculation can differ from that of a standard metered consumer. As a general point, a household consuming well inside the free-unit allowance has less billed consumption for solar to displace, which lengthens payback, while a household consuming above the threshold sees faster returns.
Non-domestic categories are generally on net feed-in rather than one-for-one net metering, meaning exports are compensated at a feed-in rate below the retail tariff. This is why commercial systems should be sized to daytime self-consumption rather than to available roof area.