Solar vs Gas Generators: Best Backup Power Choice

Where This Guide Comes From

This comparison is based on the video City Prepping published comparing solar generators and gas generators as backup power, which has more than 202,000 views. The premise is straightforward: with an aging grid and more extreme weather events, every household that depends on electricity needs a plan for when the grid goes down. The video works through the pros and cons of internal-combustion generators and solar generators, then lands on a combination strategy that most owners in the comments confirmed from real outages. We follow the same structure here, add a parameter table, and finish with the practical notes from people who have actually lived through multi-day outages.

Gas Generators: On-Demand Power With Strings Attached

The internal-combustion generator is the option most people picture: you pull it out, add fuel, and you have power on demand. That is its core strength and it is a big one — as long as you have propane, gasoline or diesel, the generator runs whether it is noon, midnight or cloudy. Upfront cost is lower than a solar setup of comparable output, and with a dual-fuel or tri-fuel model you can keep multiple fuel options so you are not locked to one source. Propane is the video's preferred fuel because it stores for years — the creator pulls a tank charged seven years earlier and runs the generator on it without an issue.

The other side of the ledger is equally clear. A gas generator is loud, and in a disaster that noise tells the neighbourhood you have power — the video uses the term OPSEC, operational security, for keeping that information to yourself. It produces carbon monoxide, which makes indoor operation lethal; post-disaster reports are full of families killed by generators run too close to a window or an HVAC intake. And it is hostage to your fuel supply: when the gas runs out you join the line at the fuel station like everyone else. Add regular maintenance and the basic mechanical skill to fix a unit when it stops mid-outage, and the "just buy a generator" answer starts looking less simple.

Solar Generators: Silent, Fume-Free, Sun-Dependent

A solar generator — a battery bank you charge from panels — flips most of those problems around. The fuel source is the sun, which means effectively unlimited energy as long as you can manage and budget your usage against what the panels deliver. There is no noise, which makes it invisible to neighbours, and no fumes, which means you can run it indoors to power a fridge or charge phones. There is no fuel to store, no queue at the gas station, and almost no maintenance — the video's routine is to pull the unit out about once a month, run it down and recharge to 50 percent to keep the cells healthy. The units are also genuinely portable: 200-watt folding panels can live in the back seat of a car.

The catch is in the name: if there is no sun, there is no charge. A few overcast days in a row — exactly when an outage is likely to happen — cut solar input hard. And the upfront cost is higher than a comparable gas generator, though the video notes the gap has been shrinking every year: a comparable solar setup cost two to three times as much six or seven years ago, and battery prices have been falling steadily since. If your need is "power for a few critical hours," solar is close to ideal; if your need is "power for an unknown number of days," solar alone starts to feel thin.

Solar Output Is Never 100 Percent: Plan for 45-70 Percent

One of the most useful corrections in the video is about rated panel output. Solar panels almost never produce their rating: on average you can expect roughly 45 to 70 percent of the panel's rated wattage, depending on conditions, orientation and cloud cover. A 400-watt panel array in decent conditions is realistically a 200-to-280-watt source for most of the day. That is fine for topping up a battery bank, but it changes the math for anything that needs sustained power.

Portable panels that can be repositioned to track the sun do meaningfully better than fixed roof or ground mounts, because they stay pointed at the sun through the day. The practical planning rule from the video is to size for the pessimistic number, not the sticker: if your fridge draws, say, 100 watts averaged over a day, plan a panel and bank combination that covers that draw with the 45-to-70 percent reality, plus one or two bad-sun days. Budget your loads first — the more power you insist on running, the more panels, batteries and cost you are committing to.

Running Either System Safely During an Outage

Safety during an outage deserves its own section, because the video is blunt about the most common killer. A gas generator must run outside, away from windows, doors, garages and any HVAC air intake — carbon monoxide is invisible and it kills people after the storm, not during it. Owners in the comments have lived this: the unit that runs for a few days, then the neighbour's unit goes quiet, and the difference is usually someone who knew where the generator could and could not sit.

For both systems, the connection into the house matters. A heavy-gauge extension cord from the unit to the fridge is the minimum; cheap flimsy cords overheat under sustained load. The ideal setup is a transfer switch wired to your main panel by an electrician, which lets you power selected critical circuits — lights, fridge, comfort outlets — without extension cords running through windows. The video makes the point that a backup system only powers what you connect it to, and a transfer switch is what turns "a generator" into "a backup system."

The Perfect Combination: Both, With a Smart Charging Loop

The video's headline conclusion is that pitting solar against gas is the wrong framing. The setup the creator keeps, and the one most commenters converged on, is both: a gas generator for the loads, and a solar generator as the silent, fuel-free backbone. The combination works because each system covers the other's weakness. When the sun is out, solar carries the house quietly. When it is not, the gas generator runs the loads and recharges the battery bank at the same time — and owners report this loop is what actually gets them through multi-day outages without panic.

The comments are full of working examples: one owner runs a propane generator twice a day for an hour each session to recharge five solar generators; another runs the generator during the day and goes silent on solar at night; a Texas owner kept his Champion 2500 inverter running on propane through a multi-day outage, charging everything including his cordless-tool batteries. The pattern is consistent — the gas generator becomes a battery charger first and a direct power source second, and the solar bank becomes the always-on, quiet base load.

Fuel Stretch: How a Battery Bank Multiplies Generator Fuel

There is a quantified reason the combination works, and it is the most useful number in the video: a battery bank can multiply your generator fuel by roughly four times. The logic is simple. A generator running continuously powers the house only while it runs. If instead you run it for a couple of hours to charge the battery bank, the bank then carries the loads for the next many hours on stored energy. One commenter's rule of thumb: two hours of generator charging buys 24 to 36 hours of battery life, which turns five gallons of gasoline into roughly two weeks of household electricity for a modest critical load.

That changes the fuel problem entirely. Instead of needing enough fuel to run a generator continuously for the whole outage, you need enough fuel to top up a battery bank each day — a much smaller number, and one that is far easier to stock. Some modern systems automate the loop: dual-fuel generator setups paired with a smart inverter can talk to each other, with the inverter signalling the generator to start when the bank gets low and shut off when it is full. The video cites the EcoFlow Delta Pro 3 with its companion 4000-watt dual-fuel generator as an example of that handshake working out of the box.

Parameter Comparison Table

The table condenses the video's comparison into one screen. The relationships — noise, fumes, fuel and maintenance — hold across brands because they come from the two technologies themselves. The "stretch fuel ~4x" figure is the combination effect owners report when the generator is used mainly to charge the battery bank rather than run continuously.

Which One for Your Region and Budget?

The final question is where you live and what you can spend. The creator is candid about his own bias: in Southern California, with year-round sun, solar is the no-brainer first choice. Somewhere with long grey winters — he names Germany and the Pacific Northwest — a solar-only system will struggle exactly when you need it, and the combination approach becomes the honest recommendation. There is no single right answer, and anyone who tells you otherwise is selling something. If you want the most resilience per dollar, budget first: work out the critical load, then build the system around it.

The owners who commented on the video mostly arrived at the same place: solar when you can, gas when you really need it. That is also how we look at it when we size a backup system — the battery bank is the always-on layer and the generator or grid is the top-up layer, and the two together beat either alone. If you are speccing a battery system for a house, a workshop or a vehicle, the same sizing logic applies, and the guides on our insights page cover load budgeting and bank sizing in more depth.

Source video: City Prepping — "Solar vs Generators...Which One Is The Best?" (youtube.com/watch?v=uXWSTXXn7UQ). Comment excerpts are quoted verbatim from the video's top comments; the original creator did not reply to these threads, so all answers are Dajiu Energy's own. Build figures are transcribed from the video's measurements.