Costs · Comparison
Solar Generator vs Gas Generator vs Standby Generator: Real Costs Compared
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There are three common ways to keep a house running when the grid goes down: a battery "solar generator" (a large portable power station you can charge from solar panels or the wall), a portable gas or dual-fuel generator, and a permanently installed standby generator that starts automatically. The sticker price is only part of the cost. Installation, fuel, maintenance and how often your power actually goes out all change the math.
The short answer
| Battery solar generator | Portable gas / dual-fuel | Whole-home standby | |
|---|---|---|---|
| Typical upfront cost | About $1,600–$2,800 for one flagship unit at the brands' own stores (Oct 2026)[1][2], plus optional panels and home wiring | $500–$2,500 for the generator, plus $400–$1,300 for a transfer switch[5] | $6,000–$11,000 installed on average; $9,500–$24,000 for larger units or long gas/electric runs[5] |
| Fuel per outage day | None while running from stored energy; about $0.75 of grid power to recharge a 4kWh battery (before charging losses)[1][7] | About $57–$86 per 24 hours for a 9,500W model at 25–50% load (our math)[4][8] | About $30–$40/day on natural gas, $150–$170/day on propane (20kW estimate)[5] |
| How long it runs | Hours to about a day on one battery, depending on load; longer with solar or expansion batteries | As long as you refuel it, about every 8–12 hours for the example model[4] | Days, on a natural gas line or a large propane tank |
| Starts automatically? | Yes, as a UPS for plugged-in devices or through a transfer panel | No. You set it up outside and start it. | Yes, through an automatic transfer switch |
| Indoor use | Yes (no combustion) | Never. Carbon monoxide risk[9] | Installed outdoors by professionals |
In plain terms: batteries cost the most per hour of backup but nothing to run and nothing to start, which suits short, frequent outages and essentials. Portable gas gives the most watts per dollar but needs fuel, attention and care with carbon monoxide. Standby generators cost the most upfront but give hands-off, multi-day, whole-house power, which suits homes that lose power for days at a time or can't go without it.
Upfront and installation costs
Battery solar generators
On October 17, 2026, the brands' own U.S. stores listed the EcoFlow DELTA Pro 3 (4,096Wh) at $2,799, marked down from $3,299[1], and the BLUETTI Apex 300 (2,764.8Wh) at $1,599, marked down from $1,699[2]. We couldn't reliably read a current price for the Anker SOLIX F3800 Plus (3,840Wh) from Anker's store page[3], so check it directly. Store prices change often and sales are common, so treat these as a snapshot.
A battery on its own powers whatever you plug into it. To run hardwired circuits like a furnace blower or well pump, you'll also need a transfer switch or the brand's home-integration panel, installed by a licensed electrician. For comparison, HomeGuide estimates a manual transfer switch for a portable generator at $400–$1,300 installed and an interlock kit at $400–$850 installed[5]. Solar panels are optional and add to the cost. Bundles exist, such as BLUETTI's Apex 300 with two 200W panels, listed at $2,399 the same day[2].
For the full spec comparison, see EcoFlow vs Bluetti vs Anker SOLIX.
Portable gas and dual-fuel generators
HomeGuide puts portable generators at $500–$2,500, plus $400–$1,300 for a transfer switch if you want to power home circuits safely[5]. As a concrete example, Westinghouse lists the WGen9500DF dual-fuel model at a manufacturer's suggested retail price of $1,249. It's rated at 9,500 running and 12,500 peak watts on gasoline, and 8,500 running and 11,200 peak on propane[4]. Retail prices vary, so check current pricing at the links below.
Whole-home standby generators
Standby generators are the big-ticket option. HomeGuide's estimate is $6,000–$11,000 installed on average, and $9,500–$24,000 for units over 20kW or installs with long fuel or electrical runs. That breaks down to roughly $3,000–$6,000 for the unit and $3,000–$5,000 for labor[5]. Line items HomeGuide lists include an automatic transfer switch ($600–$2,500), permits ($80–$450) and a concrete pad ($150–$400)[5]. A popular whole-home example is Generac's 24kW Guardian, rated at 24,000W on propane and 21,000W on natural gas[6].
| Upfront item | Battery | Portable gas | Standby |
|---|---|---|---|
| Equipment | $1,599–$2,799 (two flagship units, brand stores, Oct 17, 2026)[1][2] | $500–$2,500[5] (WGen9500DF MSRP $1,249[4]) | $3,000–$6,000 unit[5] |
| Connection to your home | Optional: transfer switch or brand panel (electrician quote) | $400–$1,300 transfer switch or $400–$850 interlock[5] | $600–$2,500 ATS, included in typical installed totals[5] |
| Installation, permits, pad | Electrician only if wired in | Electrician for switch/interlock | $3,000–$5,000 labor; permits $80–$450; pad $150–$400[5] |
| Typical total | About $1,600–$2,800 plug-in; more if wired in | About $900–$3,800 (our sum of HomeGuide ranges) | $6,000–$11,000 typical; up to $24,000[5] |
Running cost per outage day
Battery: pennies to recharge
A battery doesn't burn fuel while it runs. You pay to refill it afterward. A full charge of a 4,096Wh DELTA Pro 3 from the grid is about 4.1kWh. At the U.S. average residential electricity price of 18.31¢/kWh (EIA, July 2026)[7], that's about $0.75, plus some charging losses. Recharging from solar panels you already own costs nothing per charge. The catch is runtime: in our sizing calculator's "essentials" example (fridge, furnace fan, sump pump, lights, router), one 4,096Wh battery lasts about 11–12 hours before it needs solar, a generator or the grid.
Portable gas: about $2.40–$3.60 an hour
Westinghouse lists the WGen9500DF's 6.6-gallon tank as running up to 12 hours at 25% load and 8 hours at 50% load[4]. That's about 0.55 and 0.825 gallons per hour. At the EIA's U.S. average regular gasoline price of $4.331/gallon for the week of October 12, 2026[8]:
| Load (WGen9500DF on gasoline) | Gallons/hour | Cost/hour | 11-hour outage | 24-hour outage |
|---|---|---|---|---|
| 25% (about 2,375W) | 0.55 | about $2.38 | about $26 | about $57 |
| 50% (about 4,750W) | 0.825 | about $3.57 | about $39 | about $86 |
HomeGuide's independent estimate for a 7kW gasoline generator is $55–$70 per day[5], which is in the same range. During a big storm, gas stations may be closed or have long lines, so plan to store fuel safely and rotate it.
Standby: depends heavily on natural gas vs propane
Generac's spec sheet for the 24kW Guardian lists fuel use of 203 cubic feet per hour of natural gas at half load (306 at full load), or 2.53 gallons per hour of propane at half load (3.90 at full)[6]. Running at half load for 24 hours, that's about 61 gallons of propane a day. HomeGuide estimates a 20kW standby costs about $30–$40 per day on natural gas and $150–$170 per day on propane[5]. If you don't have a natural gas line, the size of your propane tank sets how long you can run.
Maintenance, lifespan and warranty
| Battery solar generator | Portable gas | Standby | |
|---|---|---|---|
| Routine maintenance | Keep it charged; firmware updates. No oil or filters. | Oil changes, fuel stabilizer or draining, periodic test runs (see owner's manual) | $200–$650/year for professional service[5]; automatic weekly exercise |
| Rated life | DELTA Pro 3: 4,000 cycles to 80% capacity[1]; Apex 300: 6,000 cycles[2]; F3800 Plus: 3,000+ cycles[3] | Varies by model and use | 15–30 years (HomeGuide estimate)[5] |
| Warranty | 5 years on all three flagship units (EcoFlow: 3 years + 2 with app registration)[1][2][3] | WGen9500DF: 3 years limited[4] | Varies by model and installer; check the manufacturer |
Battery cycle ratings are manufacturer claims. Even so, 4,000 full cycles would be more than ten years of daily cycling, far more than most homes use for backup alone.
Noise, power and convenience
- Noise: batteries have no engine; you'll mostly hear cooling fans. Westinghouse lists the WGen9500DF at 74 dBA[4]. Generac lists the 24kW Guardian at 67 dB(A) at 23 feet under normal load, and 57 dB(A) during its quiet weekly exercise[6].
- Power: a flagship battery delivers 3,840–6,000W continuous[1][2][3]. That's enough for essentials and some 240V loads, but not central AC plus an electric range at the same time. A 9,500W portable handles more, and a 21–24kW standby can run most whole houses[4][6].
- Convenience: standby and battery systems switch over on their own. With a portable generator, someone has to haul it outside, connect it and refuel it, often in bad weather.
- Weight and moving it: the DELTA Pro 3 weighs 113.5 lb, the Apex 300 83.8 lb and the F3800 Plus 136.7 lb[1][2][3]; the WGen9500DF weighs 211 lb[4]. All of them have wheels or are designed to sit in place.
Three scenarios
The EIA reports that U.S. electricity customers averaged about 11 hours without power in 2024. Major events like hurricanes caused about 80% of that time, and the rest of the year averaged roughly 2 hours[10]. Your own outage history is the best guide, so check your utility's records or your neighbors' experience.
1. Suburban home, a few short outages a year
You want the fridge, internet, lights and a sump pump to keep running through outages lasting a few hours. A single battery unit probably fits best. It costs about $1,600–$2,800, runs silently and indoors, switches over automatically, and recharging costs pennies. A gas generator would be cheaper to buy, but you'd be setting it up outside for a three-hour outage.
2. Storm-prone area, a few multi-day outages
You need 2–4 days of essentials. A single battery won't cover that on its own. Options: a battery plus solar panels (weather-dependent), a battery plus a small gas generator to recharge it, or a portable dual-fuel generator with a transfer switch (about $900–$3,800 total, plus roughly $57–$86 a day in gasoline for a 9,500W model at moderate load). The portable is cheapest upfront. The hybrid battery approach lets the generator run for a few hours instead of all night.
3. Whole house, can't go without power
Medical equipment, a home business, a well that supplies your water, or long rural outages: a standby generator ($6,000–$11,000 typical installed) on natural gas is the hands-off answer. Running costs are low on natural gas but high on propane. A multi-battery whole-home system is the alternative if you can't or don't want to burn fuel. EcoFlow, BLUETTI and Anker all advertise expansion to tens of kilowatt-hours, at a higher cost.
Not sure how much power you need? Start with our outage runtime calculator.
EcoFlow DELTA Pro 3(paid link) BLUETTI Apex 300(paid link) Anker SOLIX F3800 Plus(paid link)
Westinghouse WGen9500DF on Amazon(paid link) Westinghouse WGen9500DF at The Home Depot(paid link) Generac 24kW Guardian at The Home Depot(paid link)
As an Amazon Associate we earn from qualifying purchases.
Tax credits in 2026
Through 2025, battery storage of at least 3kWh could qualify for the federal Residential Clean Energy Credit (Section 25D) in some situations. According to the IRS, the credit is not available for expenditures made after December 31, 2025[11]. State and utility incentives may still exist; check with your state energy office or utility. This isn't tax advice.
Safety
Carbon monoxide from generators can kill in minutes. The U.S. Consumer Product Safety Commission says generator CO "can kill you in minutes." Never operate a portable generator inside a home, garage, basement, crawlspace or shed. Use it outside, far from the home and well away from windows, doors and vents, and always have a working CO alarm in the house[9]. The Westinghouse WGen9500DF used as an example here does not list a CO-sensing shutoff[4]. Many newer models include one, and it's worth paying for.
Never plug a generator into a wall outlet ("back-feeding"). It can electrocute utility workers and neighbors. Connect through a transfer switch or interlock installed by a licensed electrician, and follow local permit rules. Battery units are safe to use indoors but should still be wired into home circuits only by an electrician.
Sources
- EcoFlow US, DELTA Pro 3 product page (specs, warranty and price shown Oct 17, 2026): us.ecoflow.com
- BLUETTI US, Apex 300 product page (specs and price shown Oct 17, 2026); warranty: bluettipower.com/products/apex-300-home-battery-backup · BLUETTI warranty periods
- Anker SOLIX US, F3800 Plus product page and user guide: ankersolix.com/products/f3800-plus · user guide
- Westinghouse, WGen9500DF product page (watts, runtime, noise, MSRP, warranty, weight): westinghouse.com
- HomeGuide, "How Much Does a Generator Cost?" (updated Dec 30, 2025): homeguide.com/costs/generator-cost
- Generac, 24kW Guardian Series, model 7210 (product page and spec sheet): generac.com
- U.S. EIA, Electric Power Monthly, Table 5.6.A, average price of electricity to ultimate customers by state: eia.gov
- U.S. EIA, Gasoline and Diesel Fuel Update (week of Oct 12, 2026): eia.gov/petroleum/gasdiesel
- U.S. CPSC, Generators and Engine-Driven Tools: cpsc.gov
- U.S. EIA, "Hurricanes in 2024 led to the most hours without power in the United States in 10 years": eia.gov
- IRS, FAQs on modification of sections 25C, 25D and others under Public Law 119-21: irs.gov
- California Air Resources Board, "CARB approves updated regulations requiring most new small off-road engines be zero emission by 2024" (Dec 9, 2021): ww2.arb.ca.gov