After I ran the numbers on solar, the next question I kept running into was backup power. What happens when the grid goes down? Solar panels alone do not help you during an outage (most systems shut off for safety reasons). You need storage, or a generator, or both.
So I did what I do: I built another spreadsheet. Here is what I found after pricing both options.
The Generator Route
There are two types of generators worth considering for whole-home or critical-load backup: portable and standby.
Portable generators run on gasoline and cost between $800 and $3,000 depending on capacity. Champion and Westinghouse dominate this category on Amazon and have solid track records for reliability. The problems: you have to manually start them, keep fuel on hand, run extension cords or get a transfer switch installed, and they cannot run continuously for days. They are also loud and produce carbon monoxide, so they cannot be used indoors or near open windows.
Standby generators are the whole-home solution. They run on natural gas or propane, start automatically when the grid goes down, and can power your entire house. The cost range I got quoted in Columbus: $7,200 to $12,400 fully installed for a 20kW unit, which is enough for most homes. That does not include the annual maintenance contract, which runs $200 to $400 per year.
The ongoing fuel cost depends on how much you use it. During a week-long outage, a 20kW generator running at 50 percent load burns roughly 100 to 150 cubic feet of natural gas per hour. At local rates, that comes out to about $8 to $14 per hour of operation, or $75 to $130 per day at moderate usage.
The Battery Backup Route
Battery backup systems store electricity, either from the grid, solar, or both, and release it when needed. The two most common options I looked at:
If you want battery backup without committing to a full solar system, portable power stations are a middle path. The EcoFlow DELTA Pro offers 3.6kWh for around 1,800 to 2,500 dollars, can run a refrigerator and lights through a 12 to 18 hour outage, and charges from a generator, solar panels, or your wall. It is not a grid-tie solution but it works day one. (I’ve done a full EcoFlow DELTA Pro review covering 18 months of real-world use if you want the detailed breakdown.)
Tesla Powerwall 3: 13.5kWh of usable storage, around $9,200 installed (not including solar, which is required for the Powerwall 3). Enough to power a typical home for 12 to 18 hours depending on usage.
Enphase IQ Battery 5P: 5kWh per unit, scalable, around $5,800 to $7,500 per unit installed. Stacking two gives you 10kWh for about $12,000 to $14,000 installed.
The Comparison That Matters
Here is how I actually thought about this decision:
Upfront cost: Portable generator wins easily. Standby generator and battery backup are in the same ballpark for upfront investment.
Outage duration: Generator wins for long outages. A battery system is depleted in hours to a day; a generator can run indefinitely as long as you have fuel. If you live somewhere with multi-day or multi-week outages (ice storms, hurricanes), a generator handles that better.
Daily usefulness: Battery wins here completely. A battery system works every day, reducing your grid draw during peak rate hours, potentially eliminating your electric bill when paired with solar, and providing silent, zero-maintenance backup. A standby generator just sits there costing you money in annual maintenance until the power goes out.
Noise and hassle: Battery wins. Generators are loud. They require fuel. Standby units need annual servicing. Battery systems are silent and nearly maintenance-free.
Environmental impact: Battery wins if it is paired with solar. Generator loses significantly.
When a Generator Makes More Sense
I want to be honest here because I think a lot of solar-adjacent content oversells batteries. A generator is genuinely the better choice if:
- You are in an area with frequent outages lasting more than 24 to 48 hours
- You do not have or plan to get solar
- Your budget is tight and you need backup power fast (a portable generator is far cheaper)
- You have large power demands like a well pump, sump pump, HVAC, and a whole-home medical device
What I Decided
I went with solar plus a Powerwall. My reasoning: we are in central Ohio, and our outages are typically weather-related and short, rarely more than 12 to 18 hours. The Powerwall handles that easily. And the combination of solar plus battery means I am on track for a 7.1-year payback on the full system, at which point both solar and backup become essentially free.
For a deeper look at whole-home standby options versus full battery installations, I’ve covered the whole-home generator vs. battery backup comparison with actual installed cost quotes. If you are trying to decide, I recommend starting with EnergySage. I used their platform to compare quotes and it was the only place I found that gave me standardized comparisons across multiple installers without having to coordinate five separate sales calls.
Mike is a mechanical engineer in Columbus, Ohio, writing about home energy decisions from the perspective of someone who ran every number before signing anything.