Types of Generators Explained

Most generators sold to homeowners fall into four types: portable power stations, inverter generators, conventional open-frame generators and standby generators. They differ in how they make power, how loud they are and what they are built to run.

Portable power stations

A portable power station is a large rechargeable battery with outlets built in. It makes no exhaust and almost no noise, so it can run indoors. You recharge it from a wall outlet, a car or solar panels. Its limit is capacity: once the battery is empty, you must recharge it. Capacity is measured in watt-hours (Wh). Small units hold a few hundred Wh, and large ones hold several thousand.

Inverter generators

An inverter generator burns fuel, usually gasoline or propane. Its electronics smooth the output into clean, stable power, and the engine speeds up or slows down with the load. That makes it quieter and more fuel-efficient than an older design. The clean power is safe for phones, laptops and TVs. Most portable models fall between 1,000 and 4,500 watts.

Conventional open-frame generators

These are the loud, boxy machines you see on job sites. The engine runs at one fixed speed, whatever the load. They cost the least per watt and come in much larger sizes, often 5,000 to 12,000 watts or more. They are heavier, louder and burn more fuel, and their power is less clean. They suit power tools, well pumps and appliances, but not delicate electronics without protection.

Standby generators

A standby generator is installed permanently outside the home and runs on natural gas or propane from a fixed line. When the power fails, a transfer switch starts it and moves your home onto it within seconds. Residential units are commonly 10 to 26 kilowatts. They need professional installation and permits, and they cost the most up front.

At a glance

Not sure which fits? Read our power station vs. gas generator comparison, or see how each type matches a real-life situation.