Solar Battery vs Standby Generator Cost
Enter the battery and generator prices, the generator's propane burn and the outage hours you expect each year, and compare what each option costs over 10 years in your state.
Battery vs generator
D06Scenario A
Sets the electricity rate. Pick US average if you're not sure.
From EIA for US average. Use the rate on your bill if you know it.
Rate used: 18.4¢/kWh · US average · EIA reference 2025–26 · propane $2.60/gal (data as of 2026-09-26) ·
Your own estimate; we have no outage data by state.
The battery costs less over 10 years by
Battery $13,500.00 · generator $13,560.00 over 10 years with 40 outage hours a year.
- Battery (10 years)
- $13,500.00
- Standby generator (10 years: purchase + fuel + maintenance)
- $13,560.00
- Difference (battery − generator)
- −$60.00
- Generator fuel per outage hour
- $3.90
Estimate. Formula and sources are under “How it works”. Change any input; the result updates as you type.
2026 note: The federal 25C and 25D tax credits ended for installations after Dec 31, 2025. Our numbers use 2026 rules. State rebates, HEAR/HOMES programs and utility programs may still apply.
Formula
How it works
- Battery, 10 years = battery kWh × installed $ per kWh
- Generator, 10 years = installed price + outage hours × gal/h × your state's propane $/gal × 10 + maintenance × 10
- Difference = battery 10-year cost − generator 10-year cost
- Generator cost per outage hour = gal/h × propane $/gal
The battery line is the purchase only: it has no fuel and we don't add maintenance or a replacement. The generator line grows with every outage hour. That's why the answer flips with how long your outages are: short, frequent outages favor the battery; outages that last days favor the generator, because a battery without solar recharging runs out. Both totals are estimates, and every input is editable.
Sources: 22 kW standby generator at about 1.5 gal/h of propane at 50% load and $200–$400 a year in maintenance (manufacturer specifications); propane price by state from the EIA Heating Oil and Propane Update (October–March); installed battery cost from EnergySage.
Worked example
A worked example
Two batteries (27 kWh) at $950 per kWh cost $25,650.00. The generator costs $10,000, plus 120 hours × 1.8 gal/h × $3.20 per gallon (Florida propane) every year, plus $350 a year of maintenance: an estimated $20,412.00 over 10 years. Each outage hour burns $5.76 of propane. Here the battery costs $5,238.00 more.
Reference
By state, at the default inputs
The battery costs less over 10 years by, with this page's default inputs and each state's reference prices (EIA reference 2025–26, data as of 2026-09-26).
| US average | $60.00 | 18.4¢/kWh |
|---|---|---|
| Alabama | $240.00 | 15.5¢/kWh |
| Alaska | $540.00 | 25.0¢/kWh |
| Arizona | $300.00 | 15.0¢/kWh |
| Arkansas | $60.00 | 13.0¢/kWh |
| California | $600.00 | 32.0¢/kWh |
| Colorado | $60.00 | 16.0¢/kWh |
| Connecticut | $660.00 | 30.0¢/kWh |
| Delaware | $420.00 | 17.0¢/kWh |
| District of Columbia | $480.00 | 19.0¢/kWh |
| Florida | $420.00 | 15.0¢/kWh |
| Georgia | $240.00 | 14.5¢/kWh |
| Hawaii | $1,500.00 | 42.0¢/kWh |
| Idaho | $120.00 | 12.0¢/kWh |
| Illinois | $240.00 | 17.0¢/kWh |
| Indiana | $180.00 | 15.5¢/kWh |
| Iowa | $300.00 | 13.5¢/kWh |
| Kansas | $240.00 | 14.5¢/kWh |
| Kentucky | $0.00 | 13.0¢/kWh |
| Louisiana | $180.00 | 12.5¢/kWh |
| Maine | $540.00 | 26.0¢/kWh |
| Maryland | $480.00 | 19.0¢/kWh |
| Massachusetts | $660.00 | 29.0¢/kWh |
| Michigan | $180.00 | 19.5¢/kWh |
| Minnesota | $300.00 | 15.5¢/kWh |
| Mississippi | $120.00 | 13.5¢/kWh |
| Missouri | $240.00 | 13.0¢/kWh |
| Montana | $120.00 | 13.0¢/kWh |
| Nebraska | $300.00 | 12.0¢/kWh |
| Nevada | $300.00 | 15.0¢/kWh |
| New Hampshire | $600.00 | 27.0¢/kWh |
| New Jersey | $480.00 | 22.0¢/kWh |
| New Mexico | $60.00 | 15.0¢/kWh |
| New York | $600.00 | 25.0¢/kWh |
| North Carolina | $300.00 | 14.5¢/kWh |
| North Dakota | $360.00 | 11.5¢/kWh |
| Ohio | $60.00 | 16.5¢/kWh |
| Oklahoma | $240.00 | 13.0¢/kWh |
| Oregon | $180.00 | 14.5¢/kWh |
| Pennsylvania | $360.00 | 18.5¢/kWh |
| Rhode Island | $660.00 | 29.0¢/kWh |
| South Carolina | $300.00 | 15.0¢/kWh |
| South Dakota | $360.00 | 13.0¢/kWh |
| Tennessee | $180.00 | 13.5¢/kWh |
| Texas | $0.00 | 15.5¢/kWh |
| Utah | $120.00 | 12.0¢/kWh |
| Vermont | $600.00 | 22.0¢/kWh |
| Virginia | $360.00 | 15.5¢/kWh |
| Washington | $180.00 | 12.0¢/kWh |
| West Virginia | $300.00 | 15.5¢/kWh |
| Wisconsin | $240.00 | 17.5¢/kWh |
| Wyoming | $120.00 | 12.5¢/kWh |
Questions
FAQ
Battery or generator for hurricane season?
It depends on outage length. In Texas with the default prices, 10 outage hours a year make the generator $1,125.00 cheaper over 10 years; 120 hours a year make it $3,000.00 more expensive than the battery. A multi-day outage also drains a battery that has no solar to recharge it.
How much does a standby generator cost per hour of outage?
Propane only: 1.5 gal/h × $2.50 per gallon in Texas is $3.75 an hour; at the US average of $2.60 it's $3.90. Purchase and maintenance come on top whether or not the power goes out.
Can I have both?
Yes. Some homes use a battery for short outages and a generator for long ones. Add the two 10-year costs from this page to see the combined total.
Is generator runtime unlimited?
With a buried or large propane tank it runs as long as the fuel lasts. Check how many days your tank covers with the Propane Tank Duration calculator.
Why doesn't the battery have a running cost?
In this comparison the battery refills from the grid or solar between outages, and we don't price that electricity or a future replacement. That keeps the battery total low; weigh it against the battery's warranty on your quote.
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