How Much Does a House Generator Cost?

The PropertyClub Team
Oct 8th 2020
Here's what you need to know before you buy a whole-home generator, from prices on different types of generators to installation and maintenance costs.

Generators have become a popular way for homeowners to feel safe and comfortable during power outages. A home generator can kick on if your electrical grid goes out and provide your home with the energy it needs. 

Many people are pushed away from buying a generator because they don’t really know how much it would cost. The cost of installing a whole house generator can vary depending on several factors, including but not limited to your overall energy consumption, fuel type, maintenance/service, and installation needs. 

That is a lot of factors to consider. So we put together this quick guide on whole house generator costs and generator installation costs. 

Average Whole Home Generator Cost

In our estimation, the average cost for a whole home generator is approximately $12,000-$25,000 upfront plus anywhere between $200-$600 a year for maintenance and repair costs. These figures are just averages, and your specific costs may be higher or lower depending on the type of generator you get and specific installation requirements. 

Factors That Influence House Generator Costs

The key factors that influence the cost of a house generator are the cost of the unit, the installation costs, and maintenance costs for the generator. 

Cost of Different Types of Generators 

The most obvious cost will be for the generator itself. All other things being equal, bigger generators are more expensive. By “bigger,” we do not necessarily mean size, but how powerful the generator is. 

Generator power is measured in “kilowatt-hours” (kWh). The most common power ratings for whole house generators are 12kWh, 16kWh, and 20kWh units. It is imperative that you choose a correct sized generator that matches your power requirements. If you choose one that is not powerful enough, you can strain it from overuse and damage it. 

Generator cost is also affected by the type of generator. There are generators that run on gasoline, natural gas, diesel, liquid propane, and solar power.

Gasoline generators tend to be the least expensive because they are relatively well-established and common. Gasoline generators can cost anywhere between $500 for a small portable model to $3,000-$4,000 for a model that can power a medium-sized house. Gasoline is relatively cheap and available, but it has a short shelf life and is not as efficient as some other types of fuel. 

Natural gas generators are more expensive but come with some advantages as they can often be hooked directly to the city’s gas grid. Natural gas generators usually cost between $2,000-$6,000, depending on the capacity. 

Diesel generators are more powerful and are a popular option for powering an entire house. Diesel generators can cost up to $15,000 but usually fall in the $5,000-$10,000 range. Diesel engines are generally more cost-efficient than gasoline or natural gas generators if you need an appreciable amount of power. 

Propane generators fall between natural gas and diesel generators and usually cost about $2,000-$6,000. Propane generators are relatively fuel-efficient, but propane is more expensive than gasoline. Propane can also be extremely dangerous if stored incorrectly but can last a long time if stored correctly. 

Solar generators are the most recent advancement in generator technology and typically are the most expensive. A solar generator that has the battery capacity to run a medium-sized house can cost anywhere between $10,000-$20,000. There are cheap solar generators that can cost as little as $1,000, but these models are not strong enough to power a whole home. 

Generator Installation Cost

According to Home Advisor, the average cost of installing a generator is anywhere between $500-$5,000. Keep in mind that this cost is on top of the cost of the generator itself. A good rule of thumb is that the installation will cost about 50% of the generator’s cost. 

Whole-home generators are permanent fixtures and must be installed on your property. You will have to be connected to existing electrical wiring or gas hookups, depending on the model. While it is possible to install a generator yourself, it is not recommended if you do not have extensive experience working with home power systems. Your best bet is to hire a professional for installation, even if it is more expensive upfront. 

Most of the time, installers will determine costs on a project-by-project basis. Factors that can affect installation costs include:

  • Site preparation (concrete pads, foundations, etc.)
  • Upgrading your homes electrical systems
  • Connecting existing utility lines
  • Required materials and equipment
  • New wiring and upgrading existing wiring
  • Connecting fuel tanks
  • Power transfer switch

Keep in mind that if you want to use a home generator, you will need to have the generator inspected to make sure it is up to the National Electric Code, and you will have to buy a permit. You can expect to pay around $250 for an electrical permit. 

Maintenance and Upkeep

The average cost for a whole-house generator is about $400. Common maintenance issues include things like battery failures, broken spark plugs, breaker issues, gauge malfunctions, coolant problems, faulty fuel injectors, and clogged carburetors. 

You also need to consider the average cost of running the generator. Since generators are mostly for backup, you usually do not have to pay much in running costs unless you experience a long-term power outage at your location. The exact operation costs depend on how much electricity your home needs. 

For a natural gas generator, the average operating cost is about $3-$5 an hour, depending on the state you live in. So if you have to run a generator for 12 hours during a power outage, that will cost you around $36-$60. An equivalently sized propane generator can cost between $6-$10 per hour to run. 

This is one area where solar-powered generators have an advantage. You don’t have to pay for fuel because sunlight is free. However, solar generators have a lot of maintenance and upkeep costs as solar panels are still not as efficient as other types of energy.