Rooftop solar · Prosumer settlement
Net Metering & Net Billing Calculator
Two regimes now run side by side. Under net metering an exported unit cancels an imported one, so it is worth the full retail tariff. Under net billing it earns a separate, lower buyback rate. Same panels, different money — this settles your meter reading both ways and names the gap.
The bill, line by line
In the order the charges stack
| Line | How it is reached | Amount |
|---|
The two regimes
What actually differs
Net metering (agreement before 9 February 2026)
Units exported are set off one for one against units imported, and you are billed on the NET units. Because a unit out cancels a unit in, an exported unit is worth the full retail tariff to you. If exports exceed imports the surplus is carried forward as units, not paid out in the billing month.
Net billing (new connections)
Import and export are settled separately. Every imported unit is billed at the full retail tariff, and every exported unit is credited at the buyback rate NEPRA determines, which is lower. The credit is money off the bill, not a cancelled unit.
NEPRA moved new rooftop solar connections from net metering to net billing through the Prosumer Regulations notified in 2026, which repealed the 2015 net metering regulations. Existing net-metering agreements signed before the change continue on their own terms until they expire. Because the two regimes run in parallel, the same household can be told two very different things by two different installers, which is why this page shows both and the gap between them.
Before you sign anything
Four things an installer may not mention
- A negative bill is not a cheque. Under net metering a surplus is normally banked as units and carried forward; under net billing a credit larger than the bill is normally carried forward as money. Neither is usually paid out monthly. Your agreement governs.
- Fixed charges, the TV fee and any minimum charge are payable whatever your export. A solar system can take your energy charge to nothing and still leave a bill.
- Time-of-use meters price peak and off-peak units separately, and solar produces nothing at the evening peak. A system that covers all your units on paper can still leave a substantial peak bill.
- Net metering settlement is against units, not money, so its value to you moves with the retail tariff. Net billing settlement is against a separately determined rate, so its value does not.
Reading the result
Use it rather than export it
Once exported units are valued below the retail tariff, the economics change in a specific way: every unit you consume while generating is worth more than the same unit sent to the grid.
That makes load shifting genuinely valuable rather than a marginal habit. Heavy appliances run during daylight, the water pump on a timer at noon, charging done in the afternoon — each of those converts a low-value export into a full-tariff saving at no cost.
Oversizing has a limit
Under a regime that pays well for export, a larger system straightforwardly earns more. Where export is valued lower, additional capacity beyond what you can use yourself earns progressively less. The system size that made sense under net metering is not automatically the right size under net billing.
Batteries change the question, not always favourably
Storage lets you use more of your own generation instead of exporting it, which is worth the difference between the two rates. Whether that justifies the cost of the battery depends on that gap and on the battery's life — it is an arithmetic question, and worth doing before a vendor does it for you.
Where this stops
This settles one month's meter reading. Whether a system pays for itself over its life is a longer calculation involving capital cost, degradation and the value of units over twenty-odd years.
The solar panel payback calculator covers that.
FAQs
Net Metering & Net Billing FAQs
What changed between net metering and net billing?
The price your exported units fetch. Under net metering, a unit you export cancels a unit you import, so it is worth the full retail tariff. Under net billing, import and export are settled separately: you pay the retail tariff on everything you import and receive a lower, separately determined buyback rate on everything you export. The panels produce the same; the settlement is worth less.
Which regime am I on?
Your prosumer agreement says. Broadly, agreements signed before NEPRA moved new connections onto net billing in 2026 continue on net metering for their term, and new connections are on net billing. Because both run in parallel, two neighbours with identical systems can be on different terms, which is why this page shows both figures and the gap.
What buyback rate should I enter?
The one in your own agreement or DISCO notification. This page deliberately ships no default. NEPRA determines the rate and it has moved substantially; a figure hardcoded here would go stale and would then be quoted back as though it were your rate.
Why is there still a bill when I exported more than I imported?
Because fixed charges, the TV fee and any minimum charge are payable whatever you export. They sit outside the energy calculation entirely. A solar system can take your energy charge to nothing and still leave a bill of a few hundred rupees.
Do I get paid for a surplus?
Not usually as a monthly cheque. Under net metering a surplus is normally banked as units and carried forward against later months; under net billing an excess credit is normally carried forward as money. That is why this page reports a surplus as units carried forward rather than showing a negative total as if it were cash. Your agreement governs.
In what order are the taxes applied?
Electricity duty applies to the energy and adjustment charges. General sales tax applies to that total including the duty, so the two are not parallel percentages of the same base. Fixed charges and the TV fee sit outside both. Applying duty and GST side by side to the same figure understates the bill.
I have a time-of-use meter. Does this cover it?
Not in full. A TOU meter prices peak and off-peak units separately, and solar produces nothing at the evening peak, which is exactly when the peak rate applies. A system that covers all your units on paper can still leave a substantial peak bill. Run peak and off-peak separately if you want a closer figure.
Is net metering still worth it?
That turns on the gap this page calculates, on the buyback rate in your own agreement, and on how much of your generation you use in the house rather than exporting. Self-consumption is worth the full retail tariff under either regime, which is why battery and load-shifting decisions matter more under net billing than they did under net metering.
Can I estimate the payback on the system itself?
Yes, but that is a different calculation: capital cost, generation, degradation and the value of the units over the system's life. The Solar Panel Payback Calculator on this site does that. This page settles a single month's bill.
Related tools
Wondering how long the system takes to pay for itself?
Capital cost, generation, degradation and the value of the units over the system’s life.
Open the Solar Panel Payback Calculator