What kilowatt (kW) sizes are available for Generac air-cooled home standby generators? 

Generac offers air-cooled standby generators in a range of sizes from 10 to 28 kW for a variety of backup power needs. For the most accurate and up-to-date product availability and sizing recommendations, contact a Generac-authorized dealer or visit Generac.com. You can also use the Generator Sizing Tool to help determine the right size for your home and schedule a free in-home consultation. See What is a Generac In-Home Consultation (IHC) to learn how it works and the benefits it provides. 

Environment 

This article applies to Generac air-cooled standby generators.

Note: In situations where greater power is required, a larger liquid-cooled standby generator may be more appropriate. To learn more about the differences between air-cooled and liquid-cooled models, see: What Are the Benefits and Differences Between an Automatic Air-Cooled Generator and an Automatic Liquid-Cooled Generator?

10–28 kW Next Generation Series

• 2025 Lineup: 10 kW, 14 kW, 18 kW, 22 kW, 24 kW, 26 kW, 28 kW
• Generac G-Force engine sizes: 
  • 10 kW: 459cc 
  • 14 & 18 kW: 817cc 
  • 22 kW, 24 kW, 26 kW, 28 kW, (20 kW - 3 phase): 997cc
• Control panel: PZ200 (Power Zone 200)
• Battery requirement: AGM Battery Group BTX20L, 12V 330 CCA minimum - not included
• 5-Year Limited Warranty
• Mobile Link via Cellular
• Electronic Fuel Ignition & Control (EFIC) for improved performance
• Hydraulic lifters for simpler maintenance (no valve adjustment needed)

10-26 kW Guardian Series

• 2025 Lineup: 10 kW, 14 kW, 18 kW, 22 kW, 24 kW, 26kW
  • Discontinued Options: 8 kW, 9 kW, 11 kW, 13 kW, 16 kW,  20 kW
• Generac G-Force engine
• Control panel (varies by production date): Pre-nexus, Nexus, Evo 1.0, Evo 2.0 
• Battery requirement: Group 26R, 12V, 540 CCA minimum or Optional 35AGM – not ncluded
• 5-Year Limited Warranty
• Mobile Link via Wi-Fi (Cellular upgrade options available)

15 kW EcoGen

• Designed for off-grid applications using alternative energy like solar
• 2018 – Present – Run at 3600RPM and <5% THD
• Group 26R, 12V, 540CCA Minimum or Optional 35AGM – Not Included
• 3-Year Limited Warranty 

20 kW Three-Phase

• First three-phase air-cooled generator: What's the Difference Between Single-Phase and 3-Phase Power?
• Most cost-effective commercial option on the market
• 120/208 VAC only
• Group 26R, 12V, 540CCA Minimum or Optional 35AGM – Not Included
• 2018 – Includes Wi-Fi and NEC Switches (Auxiliary Shutdown)
• 5-Year Limited Warranty

Discontinued models

22 kW Response Series

• Backup power for owners and energy source for utility companies to rely on during peak demand times or capacity congestion
• Exclusively available to Generac’s Energy Alliance Partners
• Same features as Guardian Series generators
• Group 26R, 12V, 540CCA Minimum or Optional 35AGM – Not Included
• 5-Year Limited Warranty

7.5 kW PowerPact (discontinued)

• Cost-effective backup power solution
• OHV Engine
• Steel Enclosure
• External Evolution Controller 
• 30% Smaller
• Battery: Group U1, 12V, 300 CCA Minimum – Not Included
• 3-Year Limited Warranty

See also

• What's the Difference Between the Guardian, Synergy, Response, and Centurion Series Home Standby Generators?
• What Types of Engines Does Generac Use in Their Home Standby Generators?
• What Material Is the Home Standby Enclosure Made Out Of?
• What Does My Home Standby Generator Warranty Cover?
• Is there an extended warranty available for my home standby generator?
• What is the Evolution Control Panel for Home Standby Generators?
• Mobile Link Wi-Fi, Cellular, and LTE device compatibility guide