30 kW Generator
A 30 kW standby generator is appropriate for large homes with substantial electrical demands — often multiple HVAC systems, larger service sizes, and loads that exceed what air-cooled residential units handle.
Quick Answer
A 30 kW standby generator is appropriate for large homes (typically 4,000+ sq ft) with multiple HVAC systems, large central AC, electric resistance heat, and multiple high-draw appliances. At this capacity level, many installations transition to liquid-cooled equipment, which changes maintenance requirements and installation complexity. A professional load calculation and site assessment are both essential before selecting equipment at this tier.
Coverage depends on simultaneous demand and starting surges — a load calculation using your actual appliances is required to confirm.
30 kW generators are sized for homes with multiple HVAC zones or very large central AC equipment. At this tier, liquid-cooled units from brands like Generac, Kohler/Rehlko, and Cummins become the common recommendation — they run quieter under sustained load and handle higher-duty-cycle operation better than air-cooled units. The specific HVAC load (particularly starting surge) must still be verified against the generator's actual specifications.
At 30 kW, fuel demand is significantly higher than smaller residential units. On propane at 50% load, expect approximately 3.0–4.0 gallons per hour. A 1,000-gallon propane tank provides roughly 6–8 days at that rate. Natural gas units avoid the tank constraint but require confirmed meter capacity for this load level. For installations of this size, fuel supply planning is an important part of the overall design.
At 30 kW, the installation complexity increases meaningfully. Liquid-cooled units require coolant maintenance in addition to standard engine maintenance. The physical footprint is larger, clearance requirements are greater, and some jurisdictions apply commercial permit requirements to installations above a certain kW threshold. Budget more time for site assessment, permitting, and installation than a standard residential generator at 22 kW.
A 30 kW generator draws approximately 125 amps at full output on 240V. For homes with large generator loads, a 200-amp service panel may be at or near its practical limit when the generator is running the home's full load. Some 30 kW installations require 400-amp service or a subpanel approach. Electrical service capacity is a key part of the site assessment at this size tier.
Verify sizing with your actual loads
The Generator Size Calculator and Electrical Load Worksheet give you a more accurate result than any size-based rule of thumb.
