Pros and Cons of Inverter Generators
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Portable gas generators have received some technological makeovers in recent years. One is critical to safety, and one significantly boosts the level of performance for a certain breed known as inverter generators. If you’re looking into getting a portable generator, you may want to consider an inverter.
To reduce the risk of carbon monoxide poisoning, some new portable generators feature a built-in sensor that triggers an automatic shutoff if CO builds up to dangerous levels in an enclosed space. And some also have engines that emit less CO in the first place.
Many inverters now offer the CO safety shutoff—as well as the improved performance in the way of fuel efficiency and reduced noise. As a group, inverter generators are more expensive than conventional portable models, but they have distinct advantages.
An inverter generator electronically throttles the engine up and down to meet demand instead of running full tilt all the time. The resulting improvement in efficiency means that you won’t have to fill up the gas tank as often. Inverter generators also produce lower emissions and are generally very quiet.
“You can carry on a conversation next to an inverter generator,” says Dave Trezza, who oversees CR’s generator testing.
A New Class of Generator
To help you make better sense of your options, we break our inverter generator ratings into three groups:
1. Large
With very few exceptions, the large inverter generators in our ratings weigh around 250 pounds or more (wheels included). That’s too big to haul along to a tailgate party and just big enough to power your house. They generate 5,000 watts of power or more (at 220 volts).
This category of inverter generator can be connected directly to your electrical panel with a safety device called a transfer switch, which CR strongly recommends. Currently, CR has not tested any models in this class that have a CO safety shutoff, though the feature is available on the smaller inverter models.
2. Midsized
These weigh 80 pounds or more and might come with wheels. They produce 2,500 to 4,500 watts but don’t allow the recommended option of connecting to your electrical panel with a transfer switch. Instead, you plug appliances or electronics directly into the generator, which can be dangerous if you don’t follow certain guidelines.
This size is well-suited for users of recreational vehicles. These models produce all the power you need for plug-in appliances like a toaster or microwave, and they’re light enough to unload and carry away to a safe distance from your RV before use.
3. Recreational
These weigh 50 to 60 pounds and are designed to be carried with one hand. Most recreational models max out at around 2,000 watts, which should be plenty for tailgating or camping.
"Don’t let the size lull you into a false sense of security," says Trezza. "Even though they're about as big as a gym bag, our tests show that these models emit carbon monoxide at a rate that can quickly build up to unsafe levels in an enclosed space."
How to Run a Generator Safely
Consumer Reports has two dozen inverter generators in our ratings, about half of which have the automatic CO shutoff. Only those with the shutoff can earn our recommendation, regardless of how well the models perform otherwise.
They range in capability from the compact type you’d want for tailgating or camping to something that could be a steady source of basic backup power after a storm. Our generator buying guide is a great place to get a lay of the land, and our generator ratings will let you compare specific models.
CR members can read on for ratings and reviews of three top-performing inverter generators (one each from the three sizes we test).
Consumer Reports only recommends gasoline-powered generators that are designed to produce low levels of carbon monoxide, or which have an automatic shutoff mechanism, to turn off the generator in the presence of excessive carbon monoxide. Currently, none of the inverter generators in our ratings have either of these potentially life-saving features, but the models below fare extremely well in our performance tests. With any generator, it’s extremely important to follow our longstanding advice of always operating a generator a minimum of 20 feet from your house, with the exhaust directed away from any windows, doors, or air conditioners.
Generator Tips
Damaging storms can happen anytime. On the "Consumer 101" TV show, host Jack Rico learns from a Consumer Reports’ expert, Paul Hope, how to avoid being left in the dark during a power outage.
