Net Metering Savings Calculator (U.S.)

How the calculator works

The Net Metering Savings Calculator estimates your annual electricity bill before and after solar under your utility’s specific net metering or net billing structure. Unlike a simple “production × retail rate” calculation, it separately tracks the two value streams that determine real savings:

• Self-consumption — solar kWh used by your home in real time. Always worth your full retail rate, regardless of net metering regime.
• Net credit value — solar kWh exported to the grid. Worth retail rate under NEM 1.0/2.0, but only avoided cost under NEM 3.0 or Hawaii CGS+.

Plug in seven numbers and the calculator returns annual production, annual imports, annual exports, your gross bill (without solar), your net bill (with solar), annual savings in dollars, and the percentage bill reduction.

1. System size (kW) — DC nameplate. National average residential install was 7.5 kW DC per EnergySage H2 2025 marketplace data. Use the how many solar panels do I need calculator to size properly.
2. Peak sun hours/day — your NSRDB average. Phoenix 6.5, Los Angeles 5.5, Dallas 5.0, Atlanta 4.7, Chicago 4.0, Boston 4.0, Seattle 3.5. Pull from PVWatts.
3. Annual usage (kWh) — your last 12 months from utility bills. EIA reports the average U.S. residential customer used 10,791 kWh in 2024.
4. Retail rate ($/kWh) — your blended rate. EIA Form 826 February 2026 national average is $0.165/kWh. Hawaii Electric residential blended $0.42, PG&E E-TOU-C $0.42, AEP Texas $0.135.
5. Net-metering credit ($/kWh) — set to retail rate for NEM 1.0/2.0 states; set to $0.07 for NEM 3.0 California; set to your utility’s avoided-cost rate for Arizona, Nevada, or Hawaii.
6. Self-consumption (%) — 25–40% without battery, 60–85% with battery.
7. Minimum monthly bill — non-bypassable customer/grid-access charge, typically $96–$180 annually.

How the math works

annual_kWh_produced  = system_kW × peak_sun_hours × 365 × 0.77
self_consumed        = min(annual_use, annual_prod × self_pct/100)
imports_kWh          = max(0, annual_use - self_consumed)
exports_kWh          = max(0, annual_prod - self_consumed)
gross_bill           = annual_use × retail_rate + min_bill
import_cost          = imports_kWh × retail_rate
credit_value         = exports_kWh × credit_rate
net_bill             = max(min_bill, import_cost - credit_value + min_bill)
annual_savings       = gross_bill - net_bill
savings_pct          = annual_savings / gross_bill × 100

The 0.77 multiplier is the IEC 61724 system performance ratio for residential PV — covering inverter losses (3–4%), wire losses (1–2%), soiling (2–5%), high-temperature derating (5–8%), and module mismatch (1–2%). The minimum-bill floor ensures the calculator never returns savings greater than the gross bill, which would imply the utility paying you net cash. That only happens with annual true-up payouts at avoided cost, which is a separate line item, not a negative bill.

Worked example: 7 kW system in Dallas under Texas 1:1 net metering (Green Mountain Renewable Rewards)

• System: 7 kW DC, 5.0 PSH (Dallas NSRDB), retail rate $0.135 (TXU 12-month)
• Annual production: 7 × 5.0 × 365 × 0.77 = 9,840 kWh/yr
• Annual usage: 13,000 kWh (typical Texas household with AC load)
• Self-consumption 35% (no battery) → 3,444 kWh self-consumed × $0.135 = $465 saved direct
• Imports: 13,000 − 3,444 = 9,556 kWh × $0.135 = $1,290 import cost
• Exports: 9,840 − 3,444 = 6,396 kWh × $0.135 = $863 credit value
• Net bill = max($120, $1,290 − $863 + $120) = $547/yr (vs $1,875 gross)
• Annual savings: $1,328 — 71% bill reduction

Worked example: same system in Sacramento under PG&E NEM 3.0

• System: 7 kW DC, 5.4 PSH (Sacramento), retail rate $0.30 (PG&E E-TOU-C blended)
• Annual production: 7 × 5.4 × 365 × 0.77 = 10,632 kWh/yr
• Annual usage: 9,000 kWh, NEM 3.0 export rate $0.07 (CPUC ACC average)
• Self-consumption 35% no battery → 3,721 kWh × $0.30 = $1,116
• Imports: 9,000 − 3,721 = 5,279 × $0.30 = $1,584 import cost
• Exports: 10,632 − 3,721 = 6,911 × $0.07 = $484 credit value
• Net bill = max($120, $1,584 − $484 + $120) = $1,220/yr (vs $2,820 gross)
• Annual savings: $1,600 — 57% bill reduction

Now add a 13.5 kWh Tesla Powerwall (self-consumption climbs to 85%):

• Self-consumed 9,000 × 0.85 capped at use = 7,650 kWh × $0.30 = $2,295
• Imports: 9,000 − 7,650 = 1,350 × $0.30 = $405 import cost
• Exports: 10,632 − 7,650 = 2,982 × $0.07 = $209 credit value
• Net bill = max($120, $405 − $209 + $120) = $316/yr
• Annual savings: $2,504 — 89% bill reduction

The Tesla Powerwall is worth roughly $900/yr extra under NEM 3.0 because every shifted kWh moves from $0.07 export credit to $0.30 retail offset. Combined with the Section 25D 30% ITC on battery storage, the payback math becomes much friendlier than NEM 1.0 economics suggest.

State-by-state net metering snapshot (Q1 2026)

Source: DSIRE 2026, NREL State Solar Policy database, individual utility tariff sheets.

NEM 1.0, NEM 2.0, NEM 3.0 — what to enter as credit rate

NEM 1.0 — every exported kWh credited at full retail rate, NEG rolled forward indefinitely or trued up at retail. Most U.S. states pre-2018. Enter retail rate as credit rate.

NEM 2.0 — retail credit minus non-bypassable charges ($0.02–$0.03/kWh subtracted on import side); mandatory TOU rate. California 2016–2023. Enter retail rate minus $0.025 as credit rate.

NEM 3.0 / NBT — exports priced at CPUC Avoided Cost Calculator. Annual average $0.05–$0.08. Peak summer evening 5–9pm bursts to $0.50+ but represent <5% of generation. California from April 2023; the model is spreading to Arizona, Nevada, and proposed in Florida (vetoed 2022). Enter $0.07 as annual blended.

Buy-all/sell-all (Hawaii CGS+) — sell every kWh produced at FIT, buy every kWh consumed at retail. Set self-consumption to 0%, credit rate to the FIT rate ($0.15 Hawaii CGS+).

Federal ITC and the payback math

The Section 25D Residential Clean Energy Credit at 30% applies through 2032, dropping to 26% in 2033, 22% in 2034, and sunsetting in 2035. On a $22,000 7 kW system, the ITC returns $6,600 on the following year’s federal taxes, bringing net cost to $15,400. Combined with $1,328/yr savings (Texas 1:1 example), simple payback is 11.6 years; combined with $1,600/yr (CA NEM 3.0 no-battery), payback stretches to 9.6 years on the higher retail offset. Battery storage rated 3+ kWh qualifies for the same 30% ITC under the Inflation Reduction Act’s storage provision — even if installed years after the array.

Model the full cost side in our cost of solar panels calculator and the federal incentive in the solar panel tax credit calculator.

Minimum bills and demand charges — the small print

Most U.S. utilities bill a customer/grid-access charge of $8–$15/month even when your net energy is zero or negative. This is the minimum-bill floor in the calculator. North Carolina Duke residential solar customers also face a $20–$30 monthly minimum demand charge under the solar rider — your peak 15-minute import sets a minimum cost regardless of net energy. Hawaii CSS includes a $25/month fixed charge. Arizona APS residential solar customers pay a $25/month grid-access charge plus monthly demand.

Always pull your utility’s interconnection tariff before sizing. The non-bypassable charges can turn a paper $0 net energy bill into $200–$400/yr in fixed costs, which the calculator captures in the minimum-bill input.

Sources

• Database of State Incentives for Renewables & Efficiency (DSIRE), N.C. Clean Energy Technology Center, 2026 net metering policy table.
• U.S. Energy Information Administration, Form 826 February 2026 retail rate release.
• California Public Utilities Commission, NEM 3.0 / Net Billing Tariff Decision D.22-12-056 and ACC lookup tables.
• National Renewable Energy Laboratory, PVWatts Calculator and State Solar Policy database.
• EnergySage Solar Marketplace Intel Report H2 2025.
• Internal Revenue Service Section 25D Residential Clean Energy Credit (Form 5695 instructions, 2025 tax year).