Cost tool

Generator vs battery: what does it really cost to run?

The honest metric is dollars per kWh actually delivered to your loads. Set your daily energy use and how long you run it, and we compare a gas generator against a power station charged from the grid or from solar — on live national fuel and electricity prices, never a made-up number.

Daily energy use
How long
2 kWh/day · One 3-day outage · 6 kWh total

Gas generator

Cost per kWh delivered
$1.36
Total for this scenario
$8.16
Gasoline burned
1.8 gal

Burns fuel at ~3.3 usable kWh/gallon. Plus oil, maintenance, noise, and fumes that keep it outdoors.

Power station — grid

Cost per kWh delivered
$0.22
Total for this scenario
$1.32

Recharged from a wall outlet at the national residential rate, after round-trip battery loss. Silent, indoor-safe, zero fumes.

Power station — solar

Cost per kWh delivered
$0.00
Total for this scenario
$0.00

Recharged from panels: no fuel, no grid draw. Harvest depends on sun — check the solar recharge deficit tool to size an array.

Over one 3-day outage, running a power station off the grid instead of a gas generator saves about $6.84 in fuel — and recharging from solar saves the generator’s $8.16 in full. The generator still wins where you need days of uninterrupted multi-kilowatt output; for outages and camping the battery wins on cost, quiet, and indoor safety.

Power stations that replace a generator

Home-backup-capable units — ~1 kWh or larger with an 800 W+ inverter — ranked by the BatteryRank score.

EcoFlow DELTA Pro Ultra X — front view
BatteryRank score80 / 100 · Excellent
Usable AC energy (est.)
10445 Whest.. Show sourceestimated sourceus.ecoflow.com2026-07-04
Continuous AC output
12000 W. Show sourceclaimed sourceus.ecoflow.com
EcoFlow DELTA Pro 3 — front view
BatteryRank score76 / 100 · Excellent
Usable AC energy
3790 Whverified. Show sourceverified source3790Wh usable at >93% efficiency (OutdoorGearLab) vs 4096 rated2026-07-04
Continuous AC output
4000 W. Show sourceclaimed sourceus.ecoflow.com
DJI Power 2000 — front view
BatteryRank score75 / 100 · Excellent
Usable AC energy (est.)
1741 Whest.. Show sourceestimated sourcedjiusa.com2026-07-04
Continuous AC output
3000 W. Show sourceclaimed sourcedjiusa.com

Generator vs battery, straight answers

Is it cheaper to run a power station or a gas generator?
On fuel alone, a grid-charged power station is far cheaper per kWh. A gas generator delivers roughly $1.36 per kWh at today's national gas price, because a small generator turns only a fraction of the fuel's energy into usable output. Charging a battery from the grid costs about $0.22 per kWh after round-trip losses — and from solar it's effectively free. This tool compares only running cost — what the hardware costs to buy is a separate question, and we do not publish purchase prices.
Why does the generator cost so much more per kWh?
Gasoline holds about 33.7 kWh of energy per gallon, but a small portable generator's overall efficiency at partial load is only around 10–15%, so it delivers roughly 3.3 usable kWh per gallon. At national pump prices that works out to several times the cost of grid electricity — before you count oil, maintenance, and the fumes that keep a generator outdoors.
Does a power station ever cost more to run than a generator?
Essentially never on fuel. Grid electricity is cheaper per delivered kWh than gasoline through a small generator in every U.S. state, and solar recharging is free after the panels. The generator's advantage is refueling for effectively unlimited runtime and high sustained output — not running cost. Where you need days of continuous multi-kilowatt output, gas still earns its place; for outages and camping, the battery wins on cost, noise, and indoor safety.
Are these prices current?
Yes — the electricity rate is the EIA U.S. residential average (as of 2026-05-25) and the gas price is the AAA U.S. average (as of 2026-05-26). We never hardcode a made-up energy price; both are sourced constants refreshed from their publishers, so the math tracks reality.

Electricity: EIA Electric Power Monthly — U.S. residential average ($0.18/kWh, as of 2026-05-25). Gasoline: AAA — U.S. average, regular unleaded ($4.49/gal, as of 2026-05-26). Generator yield: DOE fuel-energy content (33.7 kWh/gal) × ~10% small-generator delivered efficiency. Fuel and electricity prices are national averages — your local rates will differ. Station capacity and output come from the BatteryRank database, each carrying its source and date.

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