Net Metering vs Net Feed-In in Tamil Nadu: Which Is Better for Your Solar System?
If you are planning to install a rooftop solar system in Chennai, you may have already heard two terms from solar installers:
Net Metering and Net Feed-In.
At first, both can sound confusing. But the difference is important because it can affect how the electricity generated by your solar panels is accounted for and how much value you receive from excess solar power.
For a Chennai homeowner, apartment association or business owner, understanding these two mechanisms before installing solar can help you choose the right system size and make a better investment decision.
So, which is better?
The honest answer is: it depends on your electricity consumption, consumer category, solar system size and the applicable Tamil Nadu regulations.
What Is Net Metering?
Net metering is a system where the electricity you consume from the grid and the electricity your rooftop solar system sends to the grid are measured.
Your solar panels generate electricity during the daytime.
First, your property can use the solar electricity for its own appliances and equipment.
If your solar system produces more electricity than you are consuming at that moment, the excess can flow into the grid.
When your solar generation is lower than your consumption, you draw electricity from the grid.
The meter records the import and export.
For example, suppose your home imports:
600 units
from the grid during a billing period.
Your solar system exports:
400 units
to the grid.
Under a net-metering arrangement, the basic energy calculation can be:
600 − 400 = 200 units
The exact electricity bill will still depend on the applicable tariff and other charges.
The important point is that imported and exported electricity are accounted for in energy units.
What Is Net Feed-In?
Net feed-in works differently.
Your solar electricity is still used by your property first.
If there is excess electricity, it can be exported to the grid.
However, instead of simply subtracting exported units from imported units, the electricity imported and exported is given a monetary value.
For example:
Electricity imported from grid → valued at applicable retail tariff
Electricity exported to grid → credited at applicable feed-in tariff
The export credit is then adjusted against the amount payable for electricity imported from the grid according to the applicable rules.
This means the value of one unit exported to the grid may not be the same as the value of one unit you avoid purchasing from the grid.
That difference is extremely important when calculating solar ROI.
Net Metering vs Net Feed-In: What’s the Difference?
The easiest way to remember the difference is:
Net Metering = Unit-based adjustment
Net Feed-In = Monetary adjustment
Tamil Nadu’s rooftop solar framework determines which mechanism is available based on the consumer category, system size and other applicable conditions.
Why Does This Matter for Chennai Homeowners?
Imagine you have a house in Chennai with a 5kW rooftop solar system.
During the daytime, your solar panels generate electricity.
Your home is running:
- Air conditioners
- Refrigerator
- Washing machine
- Water pump
- Fans
- Computers
- Other appliances
Some of the electricity is consumed immediately.
If your solar system generates more electricity than your house needs at that moment, the excess can be exported to the grid.
At night, your solar panels stop generating electricity and your home starts importing electricity from the grid.
This means your solar system is effectively working with the grid.
Daytime: Solar → Home → Excess to Grid
Night: Grid → Home
This is why the way imported and exported electricity is settled becomes important.
A Simple Chennai Home Example
Let’s say a household consumes:
900 units/month
Their rooftop solar system generates:
700 units/month
But the timing of consumption matters.
Suppose the house directly uses:
500 units
of the solar generation.
The remaining:
200 units
are exported to the grid.
The household may still import:
400 units
from the grid during the month.
So the energy flow looks something like:
- Solar generation: 700 units
- Direct solar consumption: 500 units
- Solar export: 200 units
- Grid import: 400 units
Under net metering, the imported and exported energy are accounted for according to the applicable net-metering rules.
Under net feed-in, the 200 exported units receive a monetary credit based on the applicable feed-in tariff, while the 400 imported units are charged according to the applicable retail tariff.
This is why the same solar system can produce different financial outcomes depending on the settlement mechanism.
Why Self-Consumption Is So Important
This is one of the most important things Chennai homeowners should understand.
Suppose your solar system generates:
25 units
during the day.
Your home consumes:
20 units
during the same period.
You can potentially use most of the solar electricity directly.
Now imagine another home that consumes only:
8 units
during the day.
The same solar system may still generate 25 units, but much more electricity could be exported.
In general, using solar electricity directly can be more valuable than exporting it, particularly where the applicable export credit is lower than the retail electricity cost.
This is why solar system sizing should be based on your electricity consumption rather than simply installing the biggest system your roof can accommodate.
Is Net Metering Better Than Net Feed-In?
For many eligible residential consumers — specifically those billed under the LA1A and LA1D tariff categories, which is who net metering is actually available to in Tamil Nadu — net metering can be financially attractive, particularly when the solar system is appropriately sized and the homeowner has regular grid consumption that can be offset by solar exports.
But that doesn’t mean net feed-in is always a bad option.
The better choice depends on your:
- Monthly electricity consumption
- Daytime electricity usage
- Solar capacity
- Solar generation
- Consumer category
- Sanctioned load
- Exported electricity
- Applicable tariff
- Current Tamil Nadu regulations
For example, a factory with significant daytime electricity consumption can still achieve strong solar savings even under a feed-in arrangement because a large portion of the solar generation may be consumed directly.
What About Commercial and Industrial Solar?
This is where Chennai business owners need to be particularly careful.
A factory, office, hotel or commercial building should not assume that residential net-metering rules automatically apply.
Different consumer categories can have different arrangements.
For industrial and commercial projects, your solar financial calculation should consider:
- Energy charges
- Demand charges
- Time-of-day charges
- Solar self-consumption
- Export value
- Applicable network charges
- System size
- Operating hours
This is especially important for factories in industrial areas such as Ambattur, Guindy, Sriperumbudur and Oragadam.
A factory that operates from 8 AM to 6 PM may have excellent solar self-consumption because its electricity demand overlaps with solar generation.
What Happens If Your Factory Runs at Night?
Suppose a factory operates three shifts.
It consumes electricity:
24 hours a day
Solar generation happens mainly during daylight hours.
Therefore, the factory will still require grid electricity during the night.
However, the solar system can reduce the amount of electricity purchased during the day.
For this type of facility, the solar investment should be calculated using the actual load profile.
If most of the solar generation is consumed directly, the project can still deliver attractive savings.
Why You Should Not Assume Exported Electricity Is Worth the Same as Imported Electricity
This is one of the biggest mistakes people make when calculating solar ROI.
Imagine, purely as an illustration:
You avoid buying:
1 unit of electricity at ₹7
But you export:
1 unit of electricity
and receive an applicable credit of:
₹3.50
The two units have different financial values.
Therefore:
Self-consumption = potentially higher value
Export = potentially lower value
The actual rates depend on the applicable Tamil Nadu tariff and regulatory framework.
There’s also a network charge to factor in on top of this — currently around ₹1.27/unit for HT industrial consumers and around ₹0.27/unit for residential rooftop. It applies to the solar units settled through the network regardless of whether the mechanism is net metering or net feed-in, so it should be built into the comparison rather than treated as a rounding error.
That’s why an accurate solar feasibility study should estimate how much electricity will be consumed directly and
how much is likely to be exported.
Should You Install a Larger Solar System?
Not necessarily.
Let’s say your house consumes around:
500 units/month
You have enough roof space for a much larger solar system.
That doesn’t automatically mean installing a 10kW system is the best financial decision.
A properly sized system should consider:
- Historical electricity consumption
- Future consumption
- Daytime load
- Roof area
- Shading
- Applicable metering mechanism
- Expected solar generation
The objective is not to generate the maximum possible electricity.
The objective is to generate useful electricity that provides maximum value to your property.
What About a 5kW Solar System in Chennai?
A 5kW rooftop solar system is a popular size for larger Chennai homes and some small commercial properties.
As a broad planning benchmark, TNPDCL (Tamil Nadu’s power distribution utility, formerly TANGEDCO) has indicated average generation of approximately 4–5 units per kW per day for grid-connected rooftop solar systems.
That means a 5kW system could potentially generate around:
20–25 units/day
or roughly:
600–750 units/month
under average conditions.
Actual production will vary depending on:
- Roof orientation
- Shading
- Panel technology
- Weather
- Dust
- Temperature
- Inverter efficiency
- System availability
So these numbers should be used for initial planning rather than as a guaranteed output.
What About a 10kW Solar System?
A 10kW system can make sense for:
- Large villas
- High-consumption homes
- Apartment common facilities
- Schools
- Offices
- Commercial buildings
- Small factories
But the applicable metering mechanism must be checked before installation.
A 10kW system may generate a significant amount of electricity, so the property’s daytime consumption becomes particularly important.
If the property cannot consume a large portion of the solar generation, more electricity may be exported.
That can change the financial calculation.
What Happens to Excess Solar Electricity?
This depends on the applicable arrangement.
Under net metering, imported and exported electricity are accounted for in units according to the applicable rules.
Under net feed-in, exported electricity receives a monetary credit based on the applicable feed-in tariff.
This is why your solar quotation should clearly explain:
- How much electricity will be self-consumed?
- How much will be exported?
- What value is assigned to exported electricity?
- How is the credit settled?
Don’t accept a solar ROI calculation that simply multiplies total solar generation by your current electricity tariff.
That can overstate potential savings.
What About Chennai’s Monsoon Season?
Chennai doesn’t receive identical sunlight every day.
During sunny periods, your solar system can generate strongly.
During cloudy or rainy periods, production can decrease.
This is normal for rooftop solar.
The grid continues to supply electricity whenever your solar system isn’t producing enough.
Therefore, solar ROI should be calculated using annual generation, rather than assuming a fixed number of units every day.
What Should You Check Before Choosing Net Metering or Net Feed-In?
Before you install rooftop solar, ask your installer:
1. Which consumer category am I?
Residential, commercial, industrial or another category?
2. What metering arrangement applies to me?
Don’t assume.
3. What is my sanctioned load?
Your solar capacity may need to be considered in relation to your sanctioned load or contracted demand.
4. How much electricity will I consume during the day?
This determines your potential self-consumption.
5. How much electricity will I export?
Ask for a realistic estimate.
6. What value is assigned to exported electricity?
This is particularly important under net feed-in.
7. What is my estimated annual saving?
Ask the installer to show the calculation.
8. What is my expected payback period?
It should be based on your actual electricity bills.
A Common Mistake: Choosing Solar Based Only on Panel Price
A cheaper solar panel doesn’t necessarily mean a cheaper solar system over 25 years.
When comparing quotations, look at:
- Panel efficiency
- Panel warranty
- Performance warranty
- Inverter quality
- Mounting structure
- Installation quality
- Monitoring system
- Maintenance
- Expected generation
- Grid approval support
A solar system is a long-term energy asset.
The goal should be long-term performance, not simply the lowest initial quotation.
Net Metering vs Net Feed-In: Which Is Better for You?
If You Are a Chennai Homeowner
Net metering can be very attractive if you are eligible and your solar system is properly sized against your electricity consumption.
If You Are a Commercial Consumer
You need to evaluate the applicable net-feed-in framework and calculate the value of both self-consumption and exported electricity.
If You Are an Industrial Consumer
Don’t make the decision based only on net metering terminology.
Look at:
Tariff + load profile + solar generation + self-consumption + export value + demand charges.
For factories, the most important question may actually be:
“How much of my solar power can I use inside my facility?”
How KinetiQ Energy Can Help
At KinetiQ Energy, solar planning should begin with your electricity consumption—not with a standard package.
A Chennai home in Anna Nagar can have a completely different load profile from a villa in OMR.
Likewise, a commercial building in Guindy can have very different energy requirements from a manufacturing facility in Ambattur or Sriperumbudur.
That’s why a proper solar assessment should look at:
- Your electricity bills
- Your consumption pattern
- Your daytime load
- Your roof area
- Your solar potential
- Your system size
- Your applicable metering arrangement
- Your expected savings
The goal is to help you choose a solar system that makes financial sense over the long term.
Net Metering or Net Feed-In?
So, which is better—net metering or net feed-in?
For an eligible residential consumer in Tamil Nadu (LA1A/LA1D), net metering can often be an attractive option because exported and imported electricity are accounted for in units under the applicable framework.
Net feed-in can also be suitable, particularly for consumer categories where it is the applicable mechanism.
But there is no universal winner.
The right choice depends on:
- Your electricity consumption
- Your daytime usage
- Your solar system capacity
- Your sanctioned load
- Your consumer category
- Your expected solar generation
- Your export volume
- The applicable Tamil Nadu tariff and regulations
The smartest approach is not to ask:
“Which metering system is popular?”
Instead, ask:
“Which arrangement gives my property the best financial outcome?”
That is the question that matters.
Planning Rooftop Solar in Chennai?
Before investing in solar, understand how your electricity will be consumed, how excess power will be treated and what your expected savings could actually be.
KinetiQ Energy can help you evaluate the right rooftop solar solution based on your property, electricity consumption and long-term energy goals.