"Generator" covers machines from a suitcase-sized unit to a trailer-mounted diesel set. Picking the right format first saves time when you ask for quotes, because each format suits different loads, sites and rental lengths.
Portable generators
Small, wheeled or hand-carried units, usually gasoline or dual-fuel. They suit a few circuits at home, small tools or a food stall. Inverter models produce cleaner, quieter power for electronics. Limits: modest output, frequent refuelling, and they need a transfer switch or inlet to connect to house wiring safely.
Towable (mobile) generators
Trailer-mounted sets, commonly diesel, delivered by the provider. They suit construction sites, events, commercial buildings and longer outages where more power and longer runtime are needed. Many offer three-phase output and sound-attenuated enclosures. Plan for delivery access, a level pad, and a qualified electrician for the connection.
Standby generators
Permanently installed units with an automatic transfer switch. These are usually bought and installed rather than rented. Temporary standby — a towable set connected to a building's prepared connection point — is the rental equivalent, often used by businesses during maintenance or extended outages.
Quick comparison
- Short outage, a few appliances: portable.
- Jobsite, event, whole building: towable.
- Critical facility needing automatic switchover: permanent standby, or a towable set on a pre-installed connection while you plan one.
What to tell providers
List the equipment you need to run, the voltage and phase, the dates, the site access, and how it will connect. Our sizing guide explains how to estimate the load.
Questions people ask
Sources
- Portable Generators — U.S. Consumer Product Safety Commission (retrieved 2026-11-05)