🔄 Net Metering Calculator

How Net Metering Works (The 3 kW Example)

Here is the exact computation the calculator runs, using a 3 kW system in a state with ₹8/unit electricity:

1. Daily generation: 3 kW × 4.5 peak sun hours = 13.5 kWh/day
2. Self-consumption: ~70% of solar generation happens while you're home and consuming. So 13.5 × 0.7 = 9.45 kWh available for self-use. If your daily usage is 10 kWh, you consume all 9.45 kWh from solar.
3. Export to grid: 13.5 − 9.45 = 4.05 kWh/day exported (the generation you didn't consume)
4. Self-consumption savings: 9.45 × 365 × ₹8 = ₹27,594/year (valued at full retail rate — units you didn't buy)
5. Export credits: 4.05 × 365 × ₹8 × 0.75 = ₹8,869/year (compensated at 75% of retail rate)
6. Total net metering benefit: ₹27,594 + ₹8,869 = ₹36,463/year

Export credit rate varies by state — some states credit exports at full retail rate, others at the Applicable Tariff for Purchase (APPC) rate, which is typically 60-80% of retail. Check your state ERC's 2026 net metering order for the exact rate. The calculator defaults to 75% as a mid-range estimate.

Self-Consumption vs Export: Where Your Savings Come From

The split between self-consumption and export matters because they are valued differently:

Self-consumption is worth more per unit than export. This is why sizing your system to match your daytime usage (not oversized) gives the best per-rupee return — every unit you self-consume saves the full retail rate, while exports only earn 60-80% of retail.

Net Metering vs Gross Metering: Which Pays More?

States use one of two metering frameworks. The difference can be significant:

• Net metering (most common for residential): Your export is netted against your import on the same bill. You pay for the net units only. Effectively, exports are valued at close to the retail rate. Most states allow net metering for systems up to 10 kW (some up to 500 kW).
• Gross metering (larger systems or where mandated): All your solar generation is exported and paid at a feed-in tariff (FiT). All your consumption is billed at full retail. If the FiT is lower than retail (usually the case), gross metering pays less than net metering.

For a typical residential 3 kW system, net metering saves ₹5,000-8,000/year more than gross metering, because the export credit rate under net metering is closer to retail. Always confirm which framework your DISCOM offers before installing.

The Common Mistake: Oversizing for Export

Some homeowners install a 5 kW system on a 2 kW consumption pattern, expecting to profit from export credits. This rarely works as expected: export compensation is 60-80% of retail (not full rate), and many states cap the maximum system size at your sanctioned load or your contract demand. The extra capacity you install at ₹50,000/kW earns only 60-80 paise per kWh exported, versus saving ₹8/kWh for self-consumed units. Size to your daytime usage first, export second.

Edge Case: Monthly Settlement vs Annual Settlement

States settle net metering credits on different cycles. Some settle monthly — any unused export credits at month-end are forfeited or paid at a lower rate. Others settle annually (March-October cycle) — credits carry forward within the settlement period. If your state settles monthly and you generate a surplus in summer but consume more in winter, you may lose credits. Check your state's settlement period and size your system so you don't generate large seasonal surpluses.

Decision Framework: Should You Rely on Net Metering?

• Daytime usage high (AC, appliances, work from home): Size system to daytime consumption. Minimal export. Best per-rupee return — every unit is self-consumed at full retail rate.
• Daytime usage low (out at work): More export. Net metering still pays, but at 60-80% of retail. Consider a smaller system or add a battery for evening use instead of exporting.
• Large roof, small bill: Don't oversize for export. Cap at 3 kW (subsidy limit) or your daytime consumption, whichever is lower. Export credits alone don't justify the extra ₹50,000/kW.
• State offers gross metering only: Run the numbers carefully. If the FiT is below ₹5/kWh, a solar system may not pay back quickly unless your daytime self-consumption is high.

The 2-Minute Self-Check

1. Check your electricity bill for daily units consumed (monthly units ÷ 30).
2. Estimate daily solar generation (system kW × your state's peak sun hours).
3. If generation > usage, you'll export the surplus — enter both in the calculator above.
4. Check your state ERC order for the export credit rate. Update the "Export Credit Rate" field if it's not 75%.
5. Compare total annual savings with and without net metering (set export credit to 0% to see the self-consumption-only savings).

Your Next Steps

1. Run the calculator with your actual generation and usage numbers.
2. Confirm your state's metering framework (net vs gross) and export credit rate with your DISCOM.
3. If you haven't sized your system yet, use the Panel Size Calculator.
4. Check your PM Surya Ghar subsidy and payback period.
5. Apply through pmsuryaghar.gov.in — net metering approval is part of the PM Surya Ghar registration process.

Editor Note

Reviewed June 2026. Net metering rules and export credit rates vary by state and are set by each state ERC. The 75% export credit default is a mid-range estimate - check your state's 2026 net metering order for the exact rate. If you spot an outdated figure, please contact us.