A generator converts mechanical energy from an internal combustion engine into electrical energy through an alternator. Generators provide backup power for off-grid solar systems during extended cloudy periods and serve as the primary power source for homesteads without renewable energy systems. Generators are rated in kilowatts of continuous output and by fuel type.
Portable generators are the most common on homesteads. They range from 1 to 10 kilowatts and run on gasoline, Propane Systems, or diesel. Portable generators are relatively inexpensive: a 5 kilowatt generator costs $500 to $1,500. They require manual starting, refueling, and connection. Portable generators are used for emergency backup and temporary power at job sites.
Standby generators are permanently installed and connected to the building's electrical system through a transfer switch. They start automatically when grid power fails and run on propane, natural gas, or diesel. Standby generators range from 5 to 50 kilowatts and cost $3,000 to $15,000 including installation. They provide seamless backup power for the entire homestead.
Inverter generators produce cleaner power with lower harmonic distortion, suitable for sensitive electronics. They adjust engine speed to match the load, improving fuel efficiency and reducing noise at low loads. Inverter generators range from 1 to 4 kilowatts and are more expensive than conventional portable generators.
Gasoline is widely available but has a short shelf life of 3 to 6 months without stabilizer. Propane stores indefinitely, burns cleanly, and produces fewer engine maintenance issues. Diesel is more fuel-efficient than gasoline and has lower fire risk but produces more exhaust odor. Dual-fuel and tri-fuel generators can operate on multiple fuel types.