Is a solar generator cheaper than a gas generator?
Not at the calculator’s default numbers: over 10 years the gas generator costs about $1,751 less. Solar also falls short on energy, delivering 86 of the 111 kWh that a home using 2.22 kWh a day needs across 5 outage days a year.
The example
The daily energy and peak load come from the home battery calculator: refrigerator, lights, Wi-Fi and phone charging, which total 2.22 kWh a day and 0.29 kW. The rest are the calculator’s defaults.
| Outage days a year | 5 |
|---|---|
| Years owned | 10 |
| Gasoline, per gallon | $4.465 |
| Peak sun hours | 4.5 |
| Gas maintenance, per year | $60 |
What the calculator finds
The gas generator is a Honda EU2200i. The solar generator is an Anker SOLIX F3800 Plus sold with one 400 W panel.
| Gas | Solar | |
|---|---|---|
| Upfront | $1,199 | $3,700 |
| Running cost a year | $75 | $0 |
| Total over 10 years | $1,949 | $3,700 |
| Cost per kWh delivered | $17.56 | $42.82 |
| Energy delivered (kWh) | 111 | 86 |
The calculator’s verdict is that the gas generator costs $1,751 less over 10 years, and the lines would cross after about 33 years.
Why gas comes out cheaper here
Upfront cost. Solar starts $2,501 higher, and its running cost is $0, so it has to make that up through fuel it does not buy.
Little fuel is bought. Gas costs $75 a year: $15 of fuel plus the $60 maintenance default. Five outage days at 2.22 kWh a day use little fuel, so solar has little fuel cost to offset.
Solar runs short. The panel adds 400 W × 4.5 × 0.80 = 1.44 kWh a day, about 1.30 kWh after the inverter. After day one, solar covers 1.3 of the 2.2 kWh a day, so five-day outages end 25 kWh short over 10 years.
How to read the cost per kWh
The last two rows of the table are the fairest comparison, because each unit is charged only for the energy it actually delivers. Gas delivers all 111 kWh the home needs, so its cost is spread across more energy. Solar delivers 86 kWh, and its much higher upfront price is spread across less. A cheaper generator that leaves a gap is not the same product as a dearer one that does not, so check the shortfall line before you read anything into the totals.
What would change the answer
More outage days raise gas fuel use but also push solar further past what one panel recharges. Pricier fuel, more years, more panels or a bigger battery all move the totals. Change any of them in the calculator and read the verdict again.
The two units
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Honda EU2200i
Gasoline, 1,800 W running, 2,200 W starting. List price $1,199. Price checked 2026-10-04.
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Anker SOLIX F3800 Plus
3.84 kWh battery, with a 400 W panel in the bundle. Bundle price $3,699.99. Price checked 2026-10-04.
Sources and what we left out
- U.S. Energy Information Administration, US average regular gasoline retail price, week of Sep 28, 2026: $4.465 a gallon.
- Honda EU2200i: output, tank and runtime, as published by Honda. Read 2026-10-04.
- Anker SOLIX F3800 Plus with a 400 W panel and its cycle rating. Read 2026-10-04.
- Centers for Disease Control and Prevention, Carbon Monoxide Poisoning Basics: use a generator only outside, more than 20 feet from windows, doors and vents, never inside a home or garage.
We left out noise, emissions and fuel storage. They are real differences, but we have no sourced figures for them, so they are not in the totals. Maintenance and the exercise runs are the calculator’s defaults.