NEM Grandfathering Impact Calculator
Find out when your net metering benefits expire and how much your savings will drop when grandfathering ends.
Already have solar? Your original net metering rate is temporary. This calculator shows your grandfathering deadline, the rate change you'll face, your annual savings impact, and the actions you should take now.
Your System Details
Approximately system size x 4-6 sun hours
Leave blank to auto-calculate from generation vs usage
Your NEM Expiration Impact
Grandfathering Deadline
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Export Rate Change
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per kWh export credit
Annual Savings Loss
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when grandfathering expires
Battery Payback Estimate
Adding a battery lets you store excess solar instead of exporting at reduced rates.
Recommended Actions
Plan Ahead Before Your Deadline
Battery installation takes 4-8 weeks. Don't wait until your grandfathering expires to act.
Get Free Solar QuotesSelect your state, utility, and enter your system details above to see your NEM grandfathering impact.
Export rates are representative values based on public utility commission records and may vary by exact rate schedule. Verify with your utility. Last updated June 2026.
Frequently Asked Questions
What is NEM grandfathering?
NEM grandfathering is a policy provision that allows existing solar customers to keep their original net metering rates and terms for a set period (typically 10-20 years) even after the state or utility introduces a less favorable successor tariff. When grandfathering expires, your export compensation drops to the current program rate.
When does my NEM 1.0 grandfathering expire?
For most states with 20-year grandfathering, your NEM 1.0 benefits expire 20 years from your Permission to Operate (PTO) date. In California, NEM 1.0 systems interconnected before July 1, 2017, so they expire between 2027 and 2037. Use the calculator above and select your state and utility to see your specific window.
How much will my solar savings drop after NEM expires?
The drop depends on the difference between your grandfathered export rate and the successor rate. In California, NEM 2.0 customers exporting at ~$0.30/kWh will see rates fall to ~$0.06/kWh under NEM 3.0 — an 80% reduction. Use the calculator to quantify your exact annual and 10-year impact.
Should I add a battery before my NEM expires?
If your annual savings loss exceeds roughly $500, a battery is usually worth exploring. A battery lets you store excess solar for self-use instead of exporting at the reduced rate, effectively preserving the value of each kWh. The calculator provides a payback estimate based on your specific numbers.
What happens to my existing solar system when NEM ends?
Your solar system keeps producing electricity exactly as before. Only the compensation for exported (excess) energy changes — it drops to the successor tariff rate. Self-consumed solar is unaffected since it offsets retail-rate purchases from the grid. Your panels, inverter, and warranty remain valid.
Can I switch utility plans to keep better rates?
Possibly. Some utilities offer time-of-use (TOU) or export-optimized plans that pay more for solar exported during peak evening hours. Switching to a TOU plan that aligns with your generation profile can partially offset the NEM expiration impact. Contact your utility to compare available rate schedules.