How Much Do Solar Panels Save Per Month?

How System Size and Home Energy Use Determine Your Savings

Your usage sets the ceiling on what solar can save. With the average U.S. home at about 865 kWh a month, an array that produces around 850 kWh covers most of a typical household’s electricity. Homes with an electric vehicle, a heat pump, a pool pump, or heavy air conditioning use more and need larger systems to save the same share of the bill.

You can work backward from a savings goal. To save $200 a month at the U.S. average rate, your panels must offset about 1,214 kWh (200 ÷ $0.1648). If a 7 kW system yields roughly 850 kWh, or about 121 kWh per installed kW, that goal points to a system near 10 kW. In California, where EIA’s 2024 average rate is 31.97¢, the same $200 requires about 626 kWh, or roughly 5 kW, but only if that energy is used on site or credited near retail.

Bigger is not automatically better. If your utility credits exported power below the retail rate, the surplus beyond your own use earns less than the electricity you displace. Ask any installer to base the proposal on at least 12 months of your actual utility bills and to account for planned loads such as an EV or heat pump.

What Solar Panels Save in Year One Versus Year 25

Monthly savings in year one are only part of the picture; what matters for your decision is how long the system takes to pay for itself. In 2026 that calculation changed. The federal Residential Clean Energy Credit (Section 25D), which returned 30% of the cost of a homeowner-purchased system, was ended by the One Big Beautiful Bill Act, signed July 4, 2025, for systems placed in service after December 31, 2025. A homeowner who buys a system with cash or a loan in 2026 should assume a net cost equal to the gross price, minus only state, local, or utility incentives. Systems that qualified in 2025 can still be claimed on that year’s return using IRS Form 5695, and unused credit carries forward.

Prices vary widely by source. The EnergySage marketplace reported an average of about $2.58 per watt in early 2026, while Lawrence Berkeley National Laboratory’s Tracking the Sun data put the 2024 median for cash-purchased residential systems near $3.50 per watt. For a 7 kW system, that is about $18,060 to $24,500 before incentives.

At about $1,681 a year in avoided electricity (850 kWh × 12 × 16.48¢), simple payback is 10.7 years at $2.58 per watt and 14.6 years at $3.50 per watt. Allowing for typical panel degradation of about 0.5% a year, as measured in NREL research, pushes break-even to roughly 11 and 15 years. Over 25 years, the same system avoids roughly $39,600 of electricity at flat 2024 U.S. average rates, a net of about $21,500 in the lower-cost case and about $15,100 in the higher-cost case, before financing costs.

Chart summary: Each line starts at the negative system cost and climbs as avoided electricity adds up. The blue line (lower price, $18,060 at $2.58 per watt) crosses zero at about year 11, and the orange line (higher price, $24,500 at $3.50 per watt) crosses at about year 15. After break-even, the remaining years are net savings, reaching about $21,500 and $15,100 by year 25. The model keeps rates flat, so it is conservative if your utility raises prices; EIA reported the national residential average rising from 16.0 to 16.5 cents between 2023 and 2024, but one year is not a forecast. In a low-rate state such as Louisiana, the same system takes about 15 years even at the lower price.

Leases and power purchase agreements work differently: a company owns the system, and your savings come from paying less per kWh than the utility charges. Whether the owner can still claim a federal commercial credit depends on deadlines and rules that apply to the owner, so ask for the contract terms, escalator, and buyout options in writing.

Sources and Methodology

All electricity prices are 2024 state and national average residential prices from the U.S. Energy Information Administration, Electric Power Annual, Table 2.10. Average household use (865 kWh a month in 2024) and the 16.0 to 16.5 cents per kWh change from 2023 to 2024 come from EIA’s Today in Energy. The end of the Section 25D credit is described by the Solar Energy Industries Association and reflected in IRS Form 5695 guidance. System prices are from the EnergySage marketplace and Lawrence Berkeley National Laboratory’s Tracking the Sun report. California export-rate figures come from industry analyses of the CPUC’s NEM 3.0 decision.

The 850 kWh a month for a 7 kW system is an illustrative assumption used so every state and payback figure is directly comparable; it is not a measured result for any location. Savings figures multiply that output by the average residential rate and assume each kWh offsets retail-priced electricity, so they overstate savings where exports are credited below retail. Payback figures ignore financing costs, maintenance, inverter replacement, and rate changes. This article is general information, not financial or tax advice; confirm incentives and your tax situation with a qualified professional.