When the power goes out in Missouri, you don't want to wonder how long it will last. A whole-house generator means your family stays comfortable, your food stays fresh, and your sump pump keeps running—regardless of what the weather does.
Why Missouri Homes Need Backup Power
Our Weather Reality
Missouri's location makes it vulnerable to multiple severe weather threats:
Summer storms: Straight-line winds, tornadoes, and severe thunderstorms regularly knock out power across the St. Louis metro
Ice storms: December and January ice accumulations can leave areas without power for days or weeks
Heat waves: Extended heat triggers rolling outages as the grid struggles with demand
2019-2024 major outages in St. Louis area: - July 2022 derecho: 500,000+ without power, some for 5+ days - January 2021 ice storm: 100,000+ without power for 3+ days - August 2020 derecho: 340,000 affected
What's at Risk During an Outage
Immediate concerns (0-4 hours): - Sump pump failure during storms - Security system offline - Garage doors inoperable - No heating/cooling
Extended outage concerns (4-24 hours): - Refrigerator/freezer food loss ($200-500 average) - Medical equipment failure - Water loss (well pumps) - Basement flooding
Prolonged outage concerns (24+ hours): - Pipe freezing in winter - Complete food loss - Health risks for vulnerable family members - Property damage from water/temperature
Whole-House vs. Portable Generators
Whole-House Standby Generators
How they work: - Permanently installed outside your home - Connected directly to your electrical panel - Automatic transfer switch detects outages - Starts within 10-30 seconds of power loss - Runs on natural gas or propane (unlimited fuel supply)
Advantages: - Fully automatic—works even when you're away - Powers entire home (or selected circuits) - No extension cords or manual setup - Professional installation ensures code compliance - Quieter operation than portable units
Portable Generators
How they work: - Manual setup required during outage - Gasoline or dual-fuel powered - Connect appliances via extension cords - Or connect to panel through manual transfer switch
Limitations: - Requires someone home to start - Fuel storage and refueling during outages - Carbon monoxide risks if improperly used - Extension cord hazards - Limited power output (typically 3,000-8,000W)
Choosing the Right Generator Size
Calculating Your Power Needs
Essential loads (minimum recommendation): - Refrigerator: 200-400W running, 1,200W starting - Sump pump: 800W running, 2,400W starting - Furnace blower: 500W running, 1,500W starting - Well pump (if applicable): 1,000W running, 3,000W starting - Lights: 500-1,000W - Minimum total: 10-14 kW
Comfortable coverage: - All essential loads plus: - Central air conditioning: 3,000-5,000W running - Electric water heater: 4,500W - Kitchen appliances - Recommended: 16-22 kW
Whole-house coverage: - Power everything simultaneously - Multiple HVAC zones - Electric vehicle charging - Premium: 24-48 kW
Popular Generator Models for St. Louis Homes
Generac Guardian Series (Most Popular) - 14-26 kW models - Wi-Fi monitoring standard - 5-year warranty - Cost: $5,000-$8,000 (unit only)
Kohler Generators - 14-48 kW models - Premium build quality - 5-year warranty - Cost: $6,000-$15,000 (unit only)
Briggs & Stratton - 12-20 kW models - Quiet operation - 6-year warranty - Cost: $4,500-$7,000 (unit only)
Installation Requirements
Electrical Requirements
Transfer switch installation: - Automatic transfer switch (ATS) required - Sized to match generator output - Connects between meter and main panel - Monitors utility power continuously
Electrical connections: - Dedicated generator circuit - Proper grounding to code - Load management for larger systems - GFCI protection where required
Gas Line Requirements
Natural gas connection: - May require gas line upgrade - Minimum 1" line typical for 20+ kW - Gas meter capacity verification - Utility involvement sometimes needed
Propane connection: - Minimum 250-500 gallon tank recommended - Proper setback distances required - Fuel delivery access needed
Placement Considerations
Code requirements: - Minimum 5 feet from windows, doors, vents - Clearance from property lines - Proper ventilation space - Snow/ice protection in winter
Practical considerations: - Noise levels (neighbor proximity) - Service access for maintenance - Fuel delivery access (propane) - Flood zone concerns
Installation Process
Timeline and Steps
Week 1-2: Planning - Site assessment - Load calculation - Generator sizing - Permit applications
Week 2-4: Preparation - Order equipment - Schedule utility coordination - Gas line work if needed - Concrete pad installation
Installation Day (1-2 days): - Generator placement - Electrical connections - Transfer switch installation - Gas line connection - System testing
Week 5-6: Finalization - Permit inspection - Homeowner training - Maintenance scheduling
Total Cost Breakdown
Generator Installation Costs (St. Louis Area, 2026)
| Component | Cost Range |
|---|---|
| Generator unit (16-22 kW) | $5,500-$8,000 |
| Automatic transfer switch | $800-$1,500 |
| Electrical installation | $1,500-$3,000 |
| Gas line work | $500-$2,000 |
| Concrete pad | $300-$600 |
| Permits and inspection | $200-$500 |
| Total installed | $9,000-$15,000 |
Factors Affecting Cost
Lower end: - Natural gas available at proper pressure - Short distance from panel - Simple installation site - Standard generator size
Higher end: - Gas line upgrades needed - Long distance from panel - Complex site conditions - Larger generator or premium brand - Load management systems
Maintenance and Operating Costs
Annual Maintenance
DIY maintenance (monthly): - Visual inspection - Check oil level - Run test cycle (automatic on most models)
Professional maintenance (annual): - Oil and filter change - Spark plug inspection - Battery check - Load test - Cost: $200-$350/year
Fuel Costs
Natural gas: - Running cost: $3-$6/hour depending on load - No fuel storage needed - Available during most outages
Propane: - Running cost: $4-$8/hour depending on load - 500 gallons provides 3-5 days of continuous operation - Requires proactive refilling
Financing Options
Ways to Fund Your Generator
Cash purchase: Best overall value
Home equity loan: Low rates, tax-deductible interest possible
Personal loan: 3-7 year terms available
Manufacturer financing: Generac and others offer promotional rates
PACE financing: Property-assessed clean energy programs in some areas
Is a Whole-House Generator Right for You?
Strongly Recommended If:
- Family member depends on medical equipment
- Home has sump pump in flood-prone area
- You work from home
- Extended travel leaves home unattended
- Previous outage caused significant loss
- Comfort during outages is a priority
Consider Alternatives If:
- Budget is limited (portable generator + transfer switch: $2,000-$3,000)
- Outages are rare in your specific area
- Home is small with minimal electrical needs
- You're planning to move soon
Get Your Free Generator Assessment
Every home is different. A professional assessment determines exactly what size generator you need, where it should be located, and what the total investment will be.
Schedule your free consultation:
Book Your Generator Assessment
First Choice Electric installs and services whole-house generators across St. Louis and St. Charles County. Our licensed electricians ensure proper sizing, code-compliant installation, and reliable operation for years to come.