Buying a portable generator can be a very overwhelming process, especially if you've never purchased one before. Let's face it, generators are handy devices and they have a nearly endless list of applications, but they aren't inexpensive. There's nothing worse than spending a lot of money for something that isn't designed to perform the job you need it to do. Our portable generator buyers guide will help you cut through the hype and find the right unit to match your specific needs.
Whether this is your first generator or a replacement, reading our portable generator buyers guide will help you select a unit that meets your power demands. We'll cover the critera you should understand in order to ensure your new generator is the right one for you.
How to Buy a Portable Generator
Benefits of a Portable Generator
Generators, on a much smaller scale, function much like your local electric power plant. However, instead of burning coal or using water to turn the turbines, a generator's engine converts diesel fuel, gasoline, natural gas, or propane into electricity.
Portable generators are extremely useful during a blackout, but they have many other uses too:
Recreation - If you want a bit of luxury on a camping trip or you're looking to power-up an appliance or two while you're tailgating before the big game, a portable generator is a great choice. You can watch TV, run a few small appliances, and even use power tools.
Emergency - A generator is an excellent resource when your electricity is no longer working. Especially after natural disasters such as hurricanes, ice storms or even wind storms. Your neighborhood may be without power, but with the help of your generator, you'll be able to get the power you need to keep your household functioning.
Some units, such as a home standby generator, are powerful enough to back up your entire house. Beyond keeping your appliances operational, they can play an essential role for individuals who rely on at-home medical equipment. But if you only want to keep several appliances running, a portable generator will typically meet your needs.
Jobsite - If you're a contractor or a hobbiest, owning a portable generator will give you the mobility necessary to run drills, paint sprayers, saws, and even an air compressor.
Types of Generators
There are three basic types of generators: Standby, portable, and inverters. Selecting the right type to meet your needs is based on a number of different factors. Let's take a closer look at each:
A standby generator is designed to provide you with the highest level of power protection. They're frequently used in commercial or industrial settings, but many homeowners also enjoy the peace-of-mind knowing that they have an electrical source during a power outage. Owning a standby generator is much like having a mini power plant in your backyard to use during an emergency.
Since standby generators are permanently mounted, they typically use an existing liquid propane (LP) or natural gas line. When the power goes out, an automatic transfer switch starts the generator so it can deliver power directly to the household's electrical panel. It's critical that a standby generator is professionally installed.
Standby generators are often large enough to keep an HVAC system up and running. Models run between 7,000 to 20,000 watts. Although, this is definitely your more expensive option, if you need 24/7 blackout power protection installing a standby generator is typically the best way to go.
Since a portable generator is designed to be mobile, they are an excellent solution if you're looking for a power source that can be easily be moved from one location to another. Their sole purpose is to deliver electrical power in locations where electricity isn't available.
Larger generators are ideal during a power outage because they can operate critical appliances such as refrigerators, sump pumps, and lights. But they are also an excellent choice for camping, tailgating, and powering jobsite tools.
The majority of portable generators run on either liquid propane (LP) or gasoline, and have a power range between 1,000 to 10,000 watts. Smaller units are relatively inexpensive, and the more powerful generators can be purchased in the $3,000 range.
Inverter generators are very popular because they operate quieter and more efficiently than a gas or diesel portable generator. Although, not as powerful as some of the larger portable generators, they still offer a power range between 800 to 3,000 watts which will meet many needs, and since they are lightweight, they are very easy to move from one location to another. In general, they tend to fall in the same price range as portable generators.
An inverter generator operates differently. They produce AC power and then converts it to DC power by utilizing an engine that's connected to an alternator. Since the DC power can be stored, these units are a particular favorite for camping, RVing, boating, and tailgating. In many cases, you can actually connect two inverter generators together and have double the power available.
Solar Powered Generators
Although most generators require gasoline to operate, it should be noted that there are solar models available. Some of the larger solar battery generators are capable of powering a large appliance for up to 24 hours, and have enough power for most any construction project. But many owners enjoy the smaller units that can operate electronics and other small items.
As a general rule, a solar generator can fully recharge using it's solar panels in about 6-hours, but they can also be charged with an AC plug, although it takes around 18-hours.
One big advantage of a solar powered generator is that they do not emit emissions. This makes them safe for indoor use, and very popular for tailgating and camping.
Understanding Power Requirements
Before you purchase your generator you'll need to determine the amount of power you'll need it to produce. The wattage it produces is what will ultimately determine which items it'll be able to power. There are two basic power measurement terms you need to understand when sizing your generator: Starting Watts and Continuous Watts.
Measurement Terms You Need to Know
Starting Watts - Starting watts is the amount of wattage required for an appliance to start up with a motor. It could be 2 to 3 times the wattage required for the appliance to run at normal operation. Although this is typically the most wattage the appliance will use, the starting watts can also be the highest level of power consumption the appliance will draw.
This is why starting watts is sometimes referred to as peak power, startup power, or maximum watts. Think of starting watts as a surge of power.
Continuous Watts - Continuous watts is the amount of watts required to operate the appliance under a normal load. It is also known as running watts, and can be thought of as rated power.
Run Time - Another term you should understand when buying a generator is run time. Manufacturers will specify the amount of time a generator will be able to operate on a single tank of fuel.
The amount of run time quoted is calculated with a full fuel tank and assumes that the generator will operate at 25% (or 50%) of it's total power. If you require more run time than the manufacturers estimate, a generator with a larger fuel tank is most often your better choice.
Why Are These Terms Important?
Starting (Surge) Wattage is the amount of power the generator is capable of producing for a short time frame. When an appliance starts up, it often requires a surge of wattage. Your generator doesn't need to produce that level of wattage all the time, it just needs to be capable of handling the surge.
Continuous (Rated) Wattage is the amount of power the generator is capable of producing continuously. If your generator is not able to meet the continuous wattage demand for a particular appliance, it will not have enough power to fuel it.
Estimating Your Power Needs
4 Steps to Determine Your Wattage Requirements
Step One: Items You'll Run Simultaneously - What is the primary reason you're buying a portable generator? Will you be using it at a construction site? Will you use it for camping? or do you want it on-hand in case of an electrical outage?
Whatever the reason, determine the amount of items you'll need your generator to power at the same time. If it's primary role will be at a construction site, which tools will it power at the same time? Powering a work light, then a circular saw, and then an electric drill individually, is very different than powering a work light and a circular saw and an electric drill at the same time.
Jot down the Continuous Watts and Starting Watts for each item that will be running at the same time.
Step Two: Calculate Continuous Watts - In order to find your Total Continuous Watts, you'll need to total the Continuous Watts for each item that will be operating at the same time. The charts below can help you find this information, or you can get the exact numbers from your owner manuals.
Using the example above: Work Light (1000 Continuous Watts); Circular Saw (1400 Continuous Watts); Electric Drill (440 Continuous Watts). Total Continuous Watts: 2840.
Step Three: Determine Starting Watts - Review the items on your list and determine which one has the highest Starting Watts.
Continuing with our example: Work Light (0); Circular Saw (2300 Starting Watts); Electric Drill (600 Starting Watts). The Circular Saw has the highest Starting Watts at 2300.
Step Four: Wattage Requirement - Now that you have both the Continuous Wattage (rated) and the Starting Wattage (surge), you simply need to add these two numbers together in order to calculate the Total Wattage Needed.
In our example: The Total Continuous Watts is 2840 and the Starting Watts is 2300, so you would need to purchase a portable generator that can provide at least 5140 Wattage.
Wattage Reference Charts
Use these charts to determine your wattage requirements. Keep in mind, that the owners manual for each tool and appliance will have the most accurate information.
Tool or Appliance
Quartz Halogen Work Light
Electric Drill – 3/8 in., 4 Amps
Electric Drill – 1/2 in., 5.4 Amps
Circular Saw – 7 1/4 in.
Air Compressor – 1/4 HP
Air Compressor – 1 HP
Electric Lawn Mower
Electric Pressure Washer
Electric Chain Saw
Electric String Trimmer
Electric Weed Trimmer
Tool or Appliance
RV AC - 13,500 BTU
TV - 42" Plasma
Radio / CD / DVD
Tool or Appliance
Refrigerator / Freezer
Sump Pump (1/3 hp)
Well Pump (1/2 hp)
Electric Water Heater
Microwave (1000 watts)
Electric Stove (8" element)
Garage Door (1/2 hp)
Computer (17" monitor)
Portable Generator Features
Since portable generators have so many different uses, there are many different features available. Here are some features you may want to consider:
Portability - Portable generators are designed to be portable, so you'll likely find a variety of features already built-in. If you're purchasing a larger generator, you may want to consider pneumatic wheels and a fold down handle.
Outlets - This is one of the more important choices you'll need to make. The type of outlets determines what you'll be able to plug into the generator. If you plan on using your generator to power your RV, you'll want to make sure it has a 120-volt RV Outlet. Do you want a USB port to charge your cell phone? How about a standard 120-volt outlet?
Think about how you'll be using your generator and what types of outlets you'll need. In addition, we recommend making sure that all the outlets are circuit breaker protected to protect the generator from an overload.
Weather Protection - One popular feature is Control Panel Weather Protection. This feature will not only protect the control panel from the rain, but also help keep dirt and other debris from collecting. It can be a real benefit even if you don't plan on using your generator in adverse weather.
Fuel Tank - Consider purchasing a generator with a large fuel tank. You'll be able to run your generator for longer periods between refueling. It's also handy to have intregrated fuel gauges so you'll always know your fuel level.
Noise Control - Generators can be quite noisy. Adding a muffler definitely helps, but if you're looking for the quietest operation possible, look for a SuperSilencer™ muffler.
Performance - If maximizing your generator's performance is important to you, look for a PowerSurge™ Alternator. These alternators deliver a large Starting Wattage. In addition, OverHead Valve (OHV) engines run quieter and longer, they also have better fuel efficiency and typically have a longer service life.
Buying the Right Generator for You
Follow these four steps to find the right portable generator that best meets your needs:
Step One: How Much Power Do You Need? - Using the information we covered above determine the amount of power you'll need your portable generator to deliver. It's best to slightly over estimate, but at the same time, you don't want to pay for power that you'll never use. Portable generators typically range between 900 to 10,000 watts.
Step Two: Portability - By it's name, a portable generator is portable. But with that said, you should consider how you'll be using it and what challenges you may face. If you'll be dragging it over uneven terrain which is common at constructions sites, you'll definitely want wheels. If you'll be transporting it from site to site, you may want a steel cage to protect it from damage. What type of handle does it have? Make sure that the generator you purchase is designed to meet your portability requirements so you'll easily be able to transport it wherever you go.
Step Three: Run Time Between Refueling - The question of how long your portable generator will run between refueling is often minimized. Refueling can be annoying and time consuming, not to mention the frustration of stopping in the middle of a project or needing to set your alarm hours before you'd normally wake up.
We recommend finding a generator that can deliver a minimum of 10 hours of runtime. This will ensure the unit has enough fuel to operate through the night and allow for a full day of work on a jobsite.
Step Four: Match the Outlets to Your Needs - Portable generators are available with a variety of different outlet options, and how you plan to use your unit will largely determine which outlets you'll need. Knowing how many appliances you'll be powering simultaneously and the type of outlets required will help ensure that your portable generator is right for the job.