Net Metering Savings Calculator — Free Online Calculator
Calculate savings from net metering with grid-tied solar. See how much you save by selling excess solar energy back to the grid.
How to Use This Calculator
Enter monthly solar production, usage, buy rate, and sell-back rate.
The Formula Explained
Savings = Self-consumed kWh × Buy rate + Exported kWh × Sell-back rate. Net bill = Imported kWh × Buy rate - Export credit.
Net Metering: Solar Economics Foundation
Net metering (or net energy metering, NEM) is the utility billing policy that determines how much value solar owners get from their systems. It sits at the intersection of technology and policy: the physical grid can easily accept excess solar exports, but the rate structure determines whether owners are compensated fairly. In states with favorable NEM rules, residential solar economics produce 5-10 year paybacks with 15% IRR. In states with poor NEM rules, the same systems struggle to reach 15-year paybacks.
The fundamental tradeoff: solar production peaks midday when residential demand is lowest, so most homes export 50-70% of their solar during the day and import 50-70% of their total usage in the evening. Net metering policies determine the economic value of this time-shifting. Full retail NEM treats exported kWh as equivalent to imported kWh (the utility is essentially a free battery). Wholesale or avoided-cost NEM pays export at 20-50% of retail, making solar less economical unless paired with batteries for self-consumption.
Worked Example: California NEM 2.0 Residential
A 10 kW solar system in Sacramento on NEM 2.0 (grandfathered until 2043 for systems installed before April 2023). Annual production: 15,000 kWh. Home annual consumption: 14,000 kWh.
Under NEM 2.0, exports and imports net at full retail rate (with small non-bypassable charges, typically 2-3 cents per kWh). Annual net: 15,000 - 14,000 = +1,000 kWh exported beyond consumption. At about 25 cents retail rate minus 2 cents non-bypassable = 23 cents effective.
Year 1 savings: (14,000 kWh × 0.25) = 3,500 USD avoided electricity cost. Plus 1,000 kWh excess × 0.23 = 230 USD generation credit. Total year 1 benefit: 3,730 USD.
Over 25-year solar lifetime with 4% annual rate escalation: total savings approximately 150,000 USD. System installed cost: 25,000 USD after tax credit. Net profit: 125,000 USD over lifetime. This is why California residential solar was so popular before NEM 3.0.
Worked Example: California NEM 3.0 Without Battery
Same 10 kW system, same consumption, but installed under NEM 3.0 (April 2023 onward). Export prices under NEM 3.0 are based on Avoided Cost Calculator, averaging 5-8 cents per kWh for most hours.
Assume 60% of solar production is exported (7,500 kWh avg morning-afternoon), 40% is self-consumed (6,000 kWh). Self-consumed solar avoids 25 cents retail × 6,000 = 1,500 USD. Exported solar at 7 cents × 7,500 = 525 USD. Total year 1 benefit: 2,025 USD.
Compare to NEM 2.0 (3,730 USD): NEM 3.0 gives only 54% of the NEM 2.0 savings. Payback extends from 7 years to 13 years. Lifetime savings drop from 150,000 USD to 80,000 USD. Solar is still economically positive but less attractive.
With a Tesla Powerwall (13.5 kWh usable) added, the home can shift afternoon solar to evening self-consumption. Self-consumption rises to 75% (11,250 kWh). Exports drop to 25% (3,750 kWh). Year 1 benefit: 11,250 × 0.25 + 3,750 × 0.07 = 2,813 + 263 = 3,076 USD. Battery cost: 15,000 USD. The battery pays back its own cost in about 14 years on NEM 3.0 economics.
Net Metering Mistakes
1. Assuming full retail NEM everywhere. Rules vary enormously by state and utility. Always check specific NEM policy for your utility before running solar ROI numbers.
2. Sizing the system for 100% annual offset under NEM 3.0. Under avoided-cost compensation, oversized systems export excess at low rates and the marginal panels don't pay back well. Size for self-consumption under poor NEM rules.
3. Ignoring non-bypassable charges. Many utilities charge small monthly fees (3-20 USD) that you cannot net out with solar. Solar customers still pay these even at zero-net.
4. Assuming NEM rules are permanent. California changed from NEM 1.0 to 2.0 to 3.0 over 15 years, each time reducing solar owner benefits. Other states have done similar. "Grandfathering" protects early adopters for a specified period (typically 20 years).
5. Overlooking battery value under poor NEM. Where NEM 3.0 or similar reduce export credit, batteries become essential for economics. Calculate solar + battery as a package, not solar alone.
NEM Policy Quick Reference by State Category
Full retail NEM states (best for solar): Most states still have full retail NEM as of 2026. New Jersey, Massachusetts, New York, Maryland, Colorado, Oregon, and many others maintain favorable rules with grandfathering.
Reduced compensation states: California (NEM 3.0), Arizona (APS has reduced NEM), Nevada, Hawaii (no NEM for new applicants, self-consumption only), Indiana (transitioning away from NEM).
No net metering states: A few states have no mandatory NEM, leaving it to utility discretion. Alabama, Mississippi, Tennessee, South Dakota have historically limited solar compensation.
Other incentive types: Some states use feed-in tariffs (FITs), paying solar owners a specific rate for all production (not just exports). Vermont, California NEM 3.0 variants use this. Other states offer SRECs (Solar Renewable Energy Credits) that create a separate revenue stream on top of NEM.
Policy and Standards
IEEE 1547 — Interconnection standards for distributed resources including solar. NEC 705 — Interconnected electric power production sources, covering the electrical installation of grid-tied solar. State-specific net metering policies are typically codified in state public utility commission regulations and utility tariff schedules.
For current information on any specific utility's NEM policy, the DSIRE database (Database of State Incentives for Renewables and Efficiency at dsireusa.org) provides regularly updated summaries of state and utility-specific programs. Always verify current rules before making solar investment decisions because policies can change.
Net metering: state-by-state policy and the math that matters
Net metering is the policy that lets your solar system "spin the meter backwards" when producing more than the house consumes. The economic value of this varies dramatically by state. Full retail net metering (1:1 credit) is the gold standard but has been rolled back in many states. Modern policies range from full retail credit to "net billing" that pays wholesale or avoided-cost for exports.
The formula and what it does
Compensation ratio is what your state and utility have decided. 1.0 = full retail credit (e.g. Massachusetts, New Jersey). 0.6-0.8 = partial (e.g. Indiana). 0.2-0.3 = wholesale or avoided cost (e.g. California NEM-3 net-billing rate). The lower the ratio, the more important self-consumption (using your own power as produced) becomes.
Worked example
Scenario: 8 kW system, 12,000 kWh/year production, 9,000 kWh/year consumption. 4,000 kWh exported during midday, 1,000 kWh imported in evening.
Under full retail NEM at 16 cents/kWh: net savings = (export_credit - import_cost) plus avoided import = 4000 x 0.16 - 1000 x 0.16 + 8000 x 0.16 = $640 - 60 + ,280 = ,760 saved. Under California NEM-3 with wholesale-priced exports (5 cents/kWh) but retail-priced imports (35 cents/kWh during peak): 4000 x 0.05 - 1000 x 0.35 + 8000 x 0.20 (avoided at blended rate) = $200 - $350 + ,600 = ,450. Slightly less, but the gap is wider on systems with more export. Adding battery storage to shift exports into peak self-consumption recovers most of the difference under NEM-3.
Approximate solar payback by state (6 kW system, average insolation)
| State | Avg install $/W (2026) | Net cost after 30% ITC | Yr 1 savings | Payback |
|---|---|---|---|---|
| California | $3.20 | 3,440 | $2,100 | ~6.4 yr |
| Massachusetts | $3.45 | 4,490 | $2,250 | ~6.4 yr |
| Arizona | $2.65 | 1,130 | ,450 | ~7.7 yr |
| Texas | $2.55 | 0,710 | ,180 | ~9.1 yr |
| Florida | $2.50 | 0,500 | ,150 | ~9.1 yr |
| New York | $3.30 | 3,860 | ,950 | ~7.1 yr |
Source: EnergySage Solar Marketplace Q1 2026 averages, NREL PVWatts annual production estimates, and current state net-metering policies. Federal Residential Clean Energy Credit (Section 25D) is 30 percent through 2032.
Common mistakes to avoid
undefinedFrequently asked questions
What states still have full retail net metering?
As of early 2026: Massachusetts, New Jersey, Illinois, Maryland, DC, Vermont, and parts of New York retain near-full retail crediting. States in transition or with capped programs: California (NEM-3), Arizona (avoided cost), Indiana (phase-out), North Carolina (Duke modified).
What is NEM-3?
California Net Billing Tariff effective April 2023. Replaces 1:1 retail crediting with avoided-cost export rates (5-8 cents/kWh typical) while keeping retail rates for imports. Significantly lowers solar-only payback; batteries become essential to capture peak-time value.
Do I get paid for excess generation at year-end?
Most states: no, or only at wholesale rate. Excess credit "true-up" varies. Some states (CO, IA) pay nothing for over-generation. A few pay wholesale (around 3 cents/kWh). Best practice: size system to about 100-110 percent of consumption, not above.
Do utility fixed charges change with solar?
No. Monthly customer charges ( 0-30 typical) remain even with zero net usage. Some states have added "grid access" fees on solar customers, ranging from a few dollars to $50/month. Check your specific tariff.
How does TOU rate structure interact with net metering?
Significantly. Under time-of-use rates, exports during peak hours (afternoon) credit at peak rate, imports during off-peak (night) charge at off-peak rate. This can swing solar economics meaningfully in either direction depending on production-vs-consumption timing.
Will my excess credits roll over month to month?
In most net metering states yes, accumulating as kWh credits on your bill. The "true-up" at year-end is what varies: some refund at avoided cost, some lose the surplus, some allow indefinite roll-over.