The short answer: choose an inverter generator if you want quiet, fuel-efficient, clean power for electronics and medical devices; choose a regular (conventional, open-frame) generator, sometimes called a genset, if you need the most watts for the money to run big loads like a well pump or several home circuits. Both make real household power, and both must run outdoors, well away from the house. The difference is how they make that power, how loud they are, how much fuel they burn and what they cost. This guide explains each one in plain terms and helps you decide which fits your home backup plan.
How each type makes electricity
Both types use a small gas or propane engine to spin an alternator. What happens next is where they split.
- Regular (conventional) generator: the alternator produces AC power directly. To keep that power at the right frequency (60 hertz in the U.S.), the engine has to run at a fixed, fairly high speed the whole time it is on, whether you are powering one lamp or a dozen appliances.
- Inverter generator: the alternator's raw output is converted to DC, then an electronic inverter rebuilds it into a smooth, steady AC wave. Because the electronics handle the frequency, the engine can speed up and slow down to match the load. As one Consumer Reports engineer put it, an inverter generator "only ramps up as high as it needs to."
That one design difference explains almost every pro and con below.
Inverter vs conventional generator at a glance
| Factor | Inverter generator | Regular (conventional) generator |
|---|---|---|
| Power quality | Very stable, clean output | Fine for most appliances, less stable |
| Noise | Quieter, especially at light loads | Louder; engine runs at full speed |
| Fuel use | Lower, because the engine throttles down | Higher at light loads |
| Watts for the money | Fewer watts per dollar | More watts per dollar |
| Size and weight | Usually more compact for the output | Bulkier open frame |
| Home servicing | Harder; parts are packed inside a case | Easier; parts are out in the open |
| 240-volt output | Mostly on larger models only | Varies by model; check the outlets |
Clean power for electronics: does it really matter?
This is the question most people searching "inverter generator" really want answered. Power quality is usually described by total harmonic distortion (THD), which measures how far the output strays from a perfectly smooth sine wave. Lower is cleaner.
Inverter generators are known for clean, consistent voltage. Consumer Reports notes that inverter models deliver "cleaner power, which can be important if you're plugging in sensitive electronic equipment or medical devices," and that all of the inverter models it recommends earned its top score for power quality, while some recommended conventional models scored slightly below that.
Here is the practical reality:
- Most household appliances run fine on a conventional generator. Refrigerators, lights, fans, sump pumps and power tools are not very fussy, and Consumer Reports says most appliances work just fine on conventional power.
- Sensitive items benefit from an inverter. Some medical equipment, computers, modern TVs, variable-speed furnace blowers and devices with delicate control boards can misbehave or be damaged by dips and spikes in voltage.
- Check the spec sheet. Many generators publish a THD figure. If clean power matters to you, compare that number across models, and if a spec sheet does not list one, ask before you buy.
If someone in your home depends on a CPAP, an oxygen concentrator or another medical device, also ask the device maker what power source they recommend. A battery-based portable power station is another clean, silent option that can run indoors for these loads.
Noise and fuel use
Because a conventional generator's engine runs at a constant speed, it is loud all the time and burns fuel even when the load is light. Popular Mechanics notes that standard generators can reach 70 decibels or more, while inverter models are often below that. Consumer Reports adds that inverter generators are "generally quiet enough not to drown out nearby conversation."
Lower noise matters more than people expect during a multi-day outage: you and your neighbors will hear the generator all night. Some neighborhoods, condo associations and campgrounds also have noise rules.
Fuel efficiency matters too. Consumer Reports points out that an inverter's efficiency means you refill less often, which can be important if gas becomes scarce after a storm. If your outages tend to last several days, that is a real advantage. Inverters also produce lower emissions than conventional models, though both still produce deadly carbon monoxide.
Power output and cost: where conventional generators win
If you need lots of watts, a conventional generator usually delivers more of them for less money. Consumer Reports describes inverter generators as significantly more expensive than conventional portable generators with comparable claimed wattage, and also harder for homeowners to service because key parts like the carburetor sit deep inside the case.
Output also affects what you can connect. According to Consumer Reports, mid-size and small inverter generators generally lack a 240-volt outlet, so they cannot be connected to your electrical panel and cannot run 240-volt equipment such as a well pump or electric water heater. The largest inverter models do offer 240-volt outlets.
Before you compare models, work out how many running and starting watts you actually need. Our guide on what size generator you need walks through the math step by step.
Which one do you need for home backup?
Match the generator to how you will use it:
- Essentials, electronics and medical devices: an inverter generator. Fridge, lights, internet, laptops, TV and a CPAP all run well on clean, quiet power.
- Heavy loads on a budget: a conventional generator. If you need a well pump, sump pump, window AC units and several circuits at once, you get more watts per dollar.
- Whole-panel backup through a transfer switch: either type, as long as it has a 240-volt outlet and enough output. A large inverter generator gives you clean power for every circuit; a conventional unit gives you more capacity for less.
- Long outages where fuel may run short: an inverter generator, for its lower fuel use, or a fuel-flexible model. See our guide to dual fuel generators, gas vs propane.
- Backup plus camping or RV trips: an inverter generator, for its lighter weight and quieter running.
You can browse inverter and dual-fuel generators to see what each size class looks like. If you would rather avoid fuel and engine maintenance entirely, a home battery backup system is worth comparing, and our guide to standby vs portable vs solar generators lays out the bigger picture.
Safety rules that apply to both
An inverter generator is not safer than a conventional one just because it is quieter or cleaner. Consumer Reports is clear that inverter generators are not inherently safer, and carbon monoxide is a serious risk with any fuel-burning generator.
- Outdoors only, far from openings. Ready.gov says generators and fuel should always be used outdoors and at least 20 feet away from windows, doors and attached garages. Never run one in a garage, basement or porch, even with the door open.
- Install carbon monoxide detectors on every level of your home, as Ready.gov recommends. Many newer generators also have a built-in CO shutoff sensor, which Consumer Reports requires for its recommended models.
- Keep it dry and let it cool before refueling. Ready.gov warns that a wet generator can cause shock and that fuel spilled on hot parts can ignite.
- Connect appliances with heavy-duty extension cords rated for the load, or have an electrician install proper transfer equipment.
- Never back-feed your house. Plugging a generator into a dryer outlet or any wall outlet with a "double male" cord is dangerous and illegal. It can send power back out onto utility lines, which Safe Electricity warns is dangerous for line workers and anyone near downed power lines, and it can start a fire in your own wiring.
Connecting a generator to your home's wiring must be done by a licensed electrician using a transfer switch or an approved interlock kit, with the permits and inspection your local code requires. Our guide to transfer switches vs interlock kits explains the options. For the rest of your outage plan, see how to prepare for a power outage.
FAQ
Is an inverter generator better than a regular generator?
It depends on the job. An inverter generator is better for quiet operation, fuel efficiency and clean power for electronics. A regular generator is better when you need the most watts for your budget or want parts that are easier to service yourself.
Can a regular generator damage electronics?
It can, depending on the generator and the device. Conventional generators produce less stable power, and some sensitive electronics and medical equipment can be affected by voltage dips and spikes. Most everyday appliances run fine. If you plan to power computers, modern TVs or medical devices, an inverter generator or a battery power station is the safer choice.
Can an inverter generator power a whole house?
Only the largest models come close, and only if they have a 240-volt outlet and enough output for your loads. Smaller inverter units are meant for plug-in appliances. For whole-home coverage, an electrician should do a load calculation and connect the generator through a transfer switch or interlock kit.
Why are inverter generators more expensive?
They contain extra electronics to convert and clean up the power, plus sound-dampening enclosures and variable-speed engine controls. Consumer Reports describes them as significantly more expensive than conventional generators with similar claimed wattage.
Can I run an inverter generator indoors or in my garage?
No. Every fuel-burning generator produces carbon monoxide. Ready.gov says to use generators only outdoors and at least 20 feet from windows, doors and attached garages. If you need indoor backup power, look at a battery-based power station instead.
This guide is general information, not electrical advice. Always have a licensed electrician connect any generator to your home's wiring, and follow your local code and permit requirements.
Not sure whether an inverter or conventional generator fits your home? Contact us with what you want to keep running and we will help you think it through.