Many homeowners are interested in using a generator to power their entire house, either as a backup energy source or even as their primary power supply. Running a house fully on a generator is possible, but there are some key factors to consider before deciding if it is the right choice. In this article, we will look at the requirements, costs, and pros and cons of powering a house solely with a generator.
What size generator is needed to run a house?
The size of generator needed to run a house full-time depends on the energy usage of the home. The average US household uses about 900 kWh of electricity per month. To determine the generator size, you need to calculate the total wattage of appliances and devices being used at one time. Here are some key factors:
- Add up the running watts (not startup watts) of all essential appliances like refrigerator, freezer, furnace/AC, well pump, lights, TV, computers, etc. This is your continuous load.
- Estimate the starting watts needed for the largest motor-driven appliances like AC compressor, well pump, refrigerator, freezer. This is your starting load.
- Choose a generator that can handle the starting load but runs comfortably at your continuous load. Increase size if you want to power more non-essentials.
For example, a 2000 sq ft home has:
- Continuous load of 5000 watts for fridge, lights, TV, etc.
- Largest starting load of 5000 watts for central AC
So a 10,000 watt (10 kW) generator would be an appropriate size. The exact size depends on your particular home’s electrical load. Consult an electrician to calculate your home’s load if unsure.
How much fuel is needed?
Fuel consumption of a generator depends on its wattage and run time. On average, a generator will use between 0.5 and 1 gallon of fuel per hour per kW of generator capacity when operating at full load.
So for the 10 kW generator in the example above running at 5000 watt continuous load, it would use about 5-10 gallons of fuel per hour. If running the generator 8 hours per day, it would consume 40-80 gallons of fuel daily.
Propane generators tend to be more fuel efficient than gasoline models. And fuel usage is lower when operating below max load. Installing an automatic transfer switch and optimizing appliance usage can improve fuel efficiency. Expect to use hundreds of gallons per month when powering a whole house.
What are the upfront costs?
The upfront costs of running a house on a generator include:
- Generator cost – Between $3,000-$10,000 depending on size and fuel type.
- Installation – $3,000-$5,000 for transfer switch, wiring, permits, labor if hiring an electrician.
- Fuel storage tank – $500-$2,000 for propane tank or gasoline storage tank.
- Initial fuel purchase – $500-$1000 to fill storage tank.
In total, expect upfront costs of $7,000 to $20,000+ to have a proper generator system installed for full house backup. Homeowners should view this as an investment in long-term energy resiliency. Proper maintenance and operation is required to get the most value long-term.
What are the electrical considerations?
Safely and legally powering your entire house with a generator requires:
- An automatic transfer switch installed by an electrician to safely transition between generator and utility power.
- Sufficient generator wattage for all household electrical loads.
- Considering a separate subpanel just for generator circuits.
- Adhering to all local building codes and permitting requirements.
Operating the generator improperly or overloading it can damage appliances or result in dangerous situations like electric shock or fire. Professional installation is highly recommended.
What are the pros of using a generator full-time?
Some of the benefits of powering a house with a generator include:
- Reliable backup power – Keeps home running during grid outages.
- Energy independence – Reduced reliance on the utility company.
- Cost savings – Potentially lower long-term costs than grid electricity.
- Clean power source – Generators can run on propane, natural gas, or solar charged batteries.
- Convenience – Automatic operation reduces disruption during outages.
For many homeowners, the appeal is having backup power if the grid goes down. For off-grid homes, a generator may be the only option. With proper sizing and installation, a generator can provide consistent and reliable power.
What are the cons of using a generator full-time?
There are also some downsides to consider:
- Upfront costs – The initial investment can be too high for some households.
- Maintenance – Generators require regular maintenance like changing oil, spark plugs, etc.
- Fuel consumption – Buying and storing fuel has costs and logistical considerations.
- Noise and fumes – Most generators create noise pollution and emit exhaust.
- Safety risks – Improper generator use can cause electrocution, fires, and carbon monoxide poisoning.
While generators provide power resiliency, they require diligent operation and maintenance. Fuel logistics, noise, and safety risks may make whole house generator systems impractical or unappealing for some homeowners.
Conclusion
Powering an entire house with a generator is technically feasible but has significant costs and logistical considerations. For essential backup power during outages, smaller portable generators are often a better solution for most homeowners. Permanently running a whole house on a generator requires carefully weighing the costs and benefits. With proper sizing, installation, maintenance, and fuel storage, generators can provide reliable off-grid living or emergency power protection. But the convenience comes at a price.