When businesses begin shopping for commercial standby generators, one of the first decisions is capacity.
Should you buy an 80kW generator?
100kW?
150kW?
200kW?
The temptation is to match generator size to building square footage.
That's rarely enough.
Commercial facilities have dramatically different electrical requirements, even when the buildings are similar in size.
The correct generator depends on what needs to continue operating when utility power fails.
Understanding Commercial Generator Capacity
Generator capacity is commonly expressed in kilowatts.
But that number tells only part of the story.
Commercial selection also needs to account for:
- Voltage
- Phase
- Power factor
- Motor starting
- Fuel
- Continuous loads
- Load sequencing
- Environmental conditions
- Future expansion
A correctly sized generator needs to support the electrical system—not merely meet a target kW number.
When to Consider an 80kW Generator
An 80kW generator can be worth evaluating for smaller commercial applications and facilities with carefully defined backup loads.
Potential applications can include:
- Small commercial buildings
- Offices
- Retail facilities
- Selected HVAC systems
- Refrigeration
- Lighting
- Security
- Communications
Whether 80kW is enough depends entirely on the actual load calculation.
A building with substantial electric heat or large compressor loads could exceed this range quickly.
When to Consider a 100kW Generator
A 100kW standby generator provides additional capacity and can be considered for medium commercial applications.
Potential loads might include:
- Multiple HVAC systems
- Refrigeration
- Pumps
- Lighting
- Office equipment
- IT equipment
- Security systems
- Selected process equipment
Motor starting still needs to be evaluated carefully.
A facility consuming less than 100kW continuously can still require a different generator solution if it has demanding motor loads.
When to Consider a 150kW Generator
The 150kW range enters larger commercial and light-industrial territory.
Potential applications can include:
- Warehouses
- Larger retail buildings
- Multi-zone HVAC
- Manufacturing operations
- Commercial refrigeration
- Larger pumps
- Business-critical electrical systems
At this capacity, electrical configuration becomes especially important.
Verify voltage, phase, fuel requirements and how loads will transfer to generator power.
When to Consider a 200kW Generator
A 200kW standby generator can support significant commercial loads.
Applications may include larger facilities with substantial HVAC, pumps, refrigeration, machinery and building systems.
But 200kW isn't automatically better simply because it's larger.
The objective remains the same: match generator capability to the facility's actual requirements.
Commercial HVAC Can Drive Generator Size
For many facilities, HVAC is one of the largest factors in generator selection.
A building may have:
- Multiple rooftop units
- Large split systems
- Heat pumps
- Air handlers
- Pumps
- Exhaust systems
- Refrigeration compressors
These systems contain motors that can produce significant starting demand.
That's why two buildings with identical normal operating kW can require different generator configurations.
120/208V vs 277/480V
Commercial electrical systems use different voltage configurations.
A building with 277/480V three-phase service requires a generator configuration compatible with the intended loads and electrical design.
Likewise, a facility operating 120/208V three-phase equipment has different requirements.
Never purchase a commercial generator based only on capacity.
Confirm:
kW + voltage + phase + fuel + electrical configuration.
Natural Gas vs. Propane
Fuel is another important consideration.
Natural gas can be convenient where adequate utility service exists.
Propane may be appropriate where natural gas isn't available or where on-site fuel storage is desired.
The fuel supply must be properly sized for the generator's demand.
This becomes increasingly important as generator capacity increases.
Which Size Is Right for My Business?
Use this sequence:
Step 1: Identify critical loads.
Step 2: Determine continuous electrical demand.
Step 3: Identify motors and compressors.
Step 4: Calculate starting requirements.
Step 5: Determine voltage and phase.
Step 6: Select fuel.
Step 7: Account for load sequencing.
Step 8: Consider future expansion.
Step 9: Match those requirements to an appropriate generator.
Only then should you decide whether 80kW, 100kW, 150kW, 200kW or another capacity is appropriate.
Buying a Commercial Briggs & Stratton Generator
ACUnitsForLess carries Briggs & Stratton commercial standby generators across multiple capacities and electrical configurations.
Before ordering, gather your facility's electrical information and equipment specifications.
For facilities with substantial heating and cooling loads, include the model and electrical data for the HVAC equipment as part of your evaluation.
The best commercial standby generator isn't necessarily the largest one.
It's the generator that can reliably support the loads your business cannot afford to lose.
Explore Briggs & Stratton Commercial Standby Generators at ACUnitsForLess.
Commercial standby-power systems should be selected, engineered and installed by appropriately qualified professionals in accordance with the manufacturer's requirements and applicable electrical, fuel, fire and building codes.
