Electric Generator Buying Guide 2026: 5 Things to Know Before You Buy

This overview page is your quick-start decision layer. Use it to prioritize what matters most, then open the dedicated best-of and comparison guides before purchase.

5 Key Factors When Buying an Electric Generator

1Inverter vs. Conventional Power

Why it matters

Conventional generators produce “dirty” power with higher Total Harmonic Distortion (THD, typically 10–25% depending on load), which can damage sensitive electronics. Inverter generators refine the power to <3% THD, making it safe for laptops and high-end appliances. They also throttle their engine speed to match demand, saving fuel and reducing noise.

What to look for

• THD Rating: Look for “Pure Sine Wave” or <5% THD for sensitive electronics.
• Acoustic Enclosure: Fully enclosed inverters operate at conversation levels (~50–60 dB) vs. open-frame models (~70–90 dB).

Expert Take

If you value your sleep or your neighbor’s sanity, the inverter is worth the premium. Conventional units are better suited for job sites where high-wattage power tools don’t care about “clean” electricity.

2Running Watts vs. Starting Watts

Why it matters

Running Watts are what the generator provides continuously, while Starting Watts cover the brief surge motor-driven appliances (like well pumps or AC units) need to kick on. Overloading a generator can trip its breaker or damage the alternator.

What to look for

• Sizing: Add the running watts of all planned devices, plus the single highest starting wattage among them.
• CO Shutdown: Modern units with CO sensors (UL 2201 or PGMA G300) are critical for safety, though they do not replace the need for 20-foot outdoor placement.

Expert Take

Never run a generator in a garage, shed, or basement, even with doors open. Carbon monoxide can reach lethal levels in minutes and drift into living spaces through vents or gaps.

3Fuel Type & Storage Longevity

Why it matters

Gasoline is easy to get but requires stabilizers for storage. Propane (LPG) has an indefinite shelf life but typically offers 15–20% less runtime per gallon than gasoline. Dual-fuel models let you use gasoline for maximum power and propane for long-term storage readiness.

What to look for

• Tank Maintenance: Inspect propane tank valves and regulators annually for rust or cracks; DOT cylinders require professional recertification every 10–12 years.
• Fuel Gauge: A physical or digital gauge is vital for monitoring runtime during multi-day outages.

Expert Take

Propane is the cleaner-burning choice that won’t gum up your carburetor. If your generator sits for months between uses, propane is the most reliable fuel source.

4Connection: Portable vs. Standby

Why it matters

A Portable generator requires manual setup and refueling during every outage. A Permanent Standby generator is installed on a pad, connected to your home’s gas line, and starts automatically via an Automatic Transfer Switch (ATS). Standby units can power entire HVAC systems, whereas portables usually focus on essential circuits.

What to look for

• Transfer Switch vs. Interlock: An interlock kit is a cost-effective way to power your panel via a portable unit; an ATS is required for automatic standby.
• Inlet Box: Ensure a professional installation of a 30A or 50A inlet box to avoid running cords through open windows.

Expert Take

If you have medical equipment or a basement prone to flooding (sump pump), the automatic nature of a standby generator is a necessary investment to ensure protection even if you aren’t home.

5Maintenance & Engine Protection

Why it matters

Electric Generators require precise maintenance to remain reliable. Most consumer engines require an initial break-in oil change at 20–25 hours, followed by an oil change every 100 hours or annually. Neglect leads to seized engines and failed starts during emergencies.

What to look for

• Hour Meter: Tracking runtime is the only way to accurately follow maintenance schedules.
• Exercise Schedule: Run your generator for at least 20–30 minutes monthly (or per manufacturer specs) under load to lubricate seals and charge the starting battery.

Expert Take

Keep a “Maintenance Kit” (spare oil, spark plug, and air filter) with the generator. During a long outage, you may hit the 100-hour mark in just 4 days, requiring an on-the-spot oil change.