A summer thunderstorm takes out power, the refrigerator goes quiet, and suddenly every appliance in the house feels urgent. The real question is not whether you want backup power. It is what generator size fits homes like yours without paying for capacity you will never use or buying a unit that cannot carry the load when it matters.
For homeowners in Richmond, Glen Allen, Henrico, Midlothian, Chesterfield, and Mechanicsville, the answer depends on the equipment you expect to run, the electrical demands of your heating and cooling system, and whether you want essentials-only coverage or more complete whole-home comfort. A properly sized generator is not a one-size-fits-all purchase. It is a plan for how your home works during an outage.
Start With the Life You Want During an Outage
The best way to size a generator is to picture a normal day when the utility power is off. Some families only need the practical basics: refrigeration, a few lights, internet equipment, a sump pump, and a furnace blower. Others want to keep central air conditioning, a well pump, an electric range, laundry equipment, and nearly every circuit available.
Those are very different goals. A generator that comfortably handles essential circuits may not have enough capacity for central air and several large appliances operating at once. On the other hand, selecting the largest available unit simply for peace of mind can increase installation cost, fuel use, and maintenance needs without delivering a meaningful benefit.
A good sizing conversation starts with two choices: Which systems must stay on, and which systems can wait until power returns? That distinction usually makes the right generator size much clearer.
What Generator Size Fits Homes With Essential Loads?
Many homes can keep key circuits operating with a generator in the 7.5 to 12 kilowatt range, although the details matter. This range often works well for homes that prioritize refrigeration, lighting, communications, garage doors, selected outlets, a gas furnace blower, and possibly a sump pump or well pump.
A basic refrigerator may use relatively modest running wattage, but compressors draw more power when starting. The same is true of pumps, motors, and many HVAC components. That is why generator sizing cannot rely on running watts alone. The generator must be able to handle short-term startup demand while other necessary loads are already operating.
For an essentials-focused setup, an electrician may install a transfer switch or a dedicated backup panel. This allows the generator to power the circuits you selected rather than trying to support every circuit in the home. It is a practical option for homeowners who want dependable backup for the systems that protect comfort, food, and property.
Typical Essential Circuits
Essential coverage commonly includes the refrigerator, freezer, kitchen lighting, selected living-area outlets, internet equipment, security equipment, garage door openers, and a sump pump. If your home has natural gas or propane heat, the generator can often support the furnace blower and controls. A gas water heater typically needs very little electricity, while an electric water heater is a much larger load.
Well pumps deserve special attention. Their running demand may look manageable on paper, but starting watts can be significant. The pump size, voltage, and controls should be verified before finalizing the generator recommendation.
When a 14 to 18 kW Generator Makes Sense
A standby generator in the 14 to 18 kW range is a common fit for homeowners who want broader coverage and fewer decisions during an outage. Depending on the home and its load-management setup, this size can often support many everyday circuits, including a larger portion of the kitchen, multiple refrigerators, lighting, outlets, a gas furnace, and one appropriately sized air-conditioning system.
That does not mean every 16 kW generator can run every item in every house at the same time. An all-electric home, a large heat pump, electric water heating, electric cooking, and a pool pump can quickly raise the demand. In these cases, intelligent load management may temporarily prevent lower-priority equipment from operating while higher-priority equipment starts or runs.
Load management is not a compromise in workmanship. It is a thoughtful way to make generator capacity work efficiently. For example, a system can prioritize the HVAC equipment and essential circuits while holding off an electric water heater or EV charger until sufficient capacity is available.
Larger Homes and Whole-Home Backup
A 20 to 26 kW standby generator is often considered for larger homes, homes with multiple HVAC systems, or households that want close-to-normal operation during outages. It may also be appropriate when the home has a well pump, significant refrigeration needs, a finished basement, or other equipment the homeowner does not want to shut down.
Still, “whole-home” does not always mean every electrical load can run at full demand simultaneously. A large electric range, clothes dryer, heat pump auxiliary heat, electric water heater, spa, and EV charger can create a much higher peak demand than the rest of the house. The right solution may be a larger generator, a load-management system, or a clear plan for which high-demand appliances are used during an outage.
Homes with fully electric heating require especially careful review. Electric resistance heat can demand far more power than a gas furnace blower, and auxiliary heat strips in a heat pump can change the calculation significantly during cold weather. A generator should be sized for the conditions you may actually face, not just a mild-weather estimate.
Why Appliance Labels Are Only the Beginning
It is tempting to add up appliance wattages from online charts and choose the next generator size above the total. That can provide a rough starting point, but it is not enough for a safe, dependable installation.
A professional assessment looks at the home’s electrical panel, major appliance nameplates, HVAC data, voltage requirements, motor startup loads, and the way circuits are grouped. It also considers whether you have 120-volt and 240-volt equipment. A portable generator that only supports selected 120-volt loads is very different from an automatic standby generator connected through an approved transfer system.
Your electrical service size also matters, but it does not automatically determine generator size. A home with a 200-amp electrical service does not necessarily need a generator capable of supplying the full 200 amps. The goal is to support your chosen outage loads safely and realistically.
Fuel Supply Affects the Right Choice
Generator capacity and fuel supply go together. Standby generators commonly operate on natural gas or propane. Natural gas can be convenient where service is available, while propane can be a strong option for homes outside gas service areas. In either case, the fuel supply must be sized to support the generator at the expected load.
A larger generator generally consumes more fuel, especially when it is working hard. That is another reason not to oversize without a reason. At the same time, undersizing can mean frequent overloads, reduced comfort, and a generator that cannot do the job you bought it to do.
Portable generators usually run on gasoline, propane, or dual-fuel arrangements. They can be useful for limited, temporary backup, but they require manual setup, safe outdoor placement, fuel management, and a properly installed connection method. They should never be operated in a garage, basement, enclosed porch, or near doors and windows because carbon monoxide is a serious hazard.
Do Not Skip the Transfer Switch
A generator must connect to your home through approved equipment. A transfer switch prevents generator power from feeding back onto utility lines, which can endanger utility workers and damage equipment. It also gives you a controlled, organized way to power the selected circuits or transition the home to standby power.
Never attempt to power a home by plugging a generator into a dryer outlet or another household receptacle. This practice, sometimes called backfeeding, is dangerous and not an acceptable substitute for a correctly installed transfer switch or generator inlet.
For automatic standby systems, the transfer equipment senses an outage, starts the generator, and shifts the selected loads to backup power. When utility power returns, the system transfers back and the generator shuts down after its cooldown cycle. That convenience is especially valuable for homeowners who travel, have medical equipment, or simply do not want to manage an outage in bad weather.
A Sizing Visit Brings the Answer Into Focus
The most useful generator recommendation is based on your home, not a generic chart. During a site evaluation, the electrician can identify critical loads, inspect panel capacity and available space, review your heating and cooling equipment, and discuss where the generator and fuel connection can be located. This is also the time to talk through noise, clearance requirements, permits, and ongoing service.
M.W. Butler Electrical can help Richmond-area homeowners make those choices with clear recommendations and careful installation. The objective is simple: enough backup power for the way you live, installed correctly and ready when the lights go out.
Before choosing a model, make a short list of what you would not want to lose during a 24-hour outage. That list, combined with a professional load calculation, is the clearest path to a generator that feels dependable rather than uncertain.