Portable Electric Generator

If you've ever been a victim of a lengthy power outage due to severe weather, odds are you are now a firm believer in having a generator stored in your garage for the next time you need it. A good generator can supply your home with the essential electricity it needs to help life stay as normal as possible until the utility company can make their repairs. Yet not all generators are designed for powering a home. In truth, generators are used for a broad range of purposes.

If you're looking to purchase your first generator, it can be a confusing process because there are so many different varieties available. For instance, some turn on automatically when the electrical panel loses service, while others need to be pull-started like a lawnmower. Some are portable, and some are not. Some use gasoline, while others use propane. The purpose of this buyer's guide is to provide you with information you need to help you find the right generator for your needs.

Diesel generators-A diesel generator is one that runs on diesel fuel, which in some areas may be less expensive than gasoline. Available in a variety of sizes, smaller diesel generators ranging from 1,000 to 10,000 watts are often used by construction companies to power certain pieces of equipment or for a source of auxiliary power in mobile homes, whereas generators sized 8,000 to 30,000 watts are generally large enough for a home or small office. Diesel generators are available under a range of classifications, including these:

  • Industrial diesel generators
  • Silent diesel generators
  • Diesel electric generators
  • Standby diesel generators
  • Diesel power generators
  • Diesel home generators

Electric Generators-The purpose of all generators both large and small, is to produce electricity for one purpose or another, so all generators can be classified as electric. However, some generators have the ability to be started by either electric switch or by a remote control device in addition to the manual rip-cord starting method. These types of generators fall under the electric generator classification. Types of electric generators include the following:

  • Electric start generators
  • Electric portable generators
  • Gas electric generators
  • Electric home generators
  • Electric propane generators

Gas generators-Gas generators are electricity-producing generators that are powered by gasoline, diesel or natural gas. While gasoline and diesel models are available in portable models, natural gas-powered generators are strictly permanent, as they are connected to the home's natural gas line.

Propane generators-A propane-fueled generator is powered by two or more tanks of propane gas. They are often preferred over gas generators because they burn cleaner with less toxic emissions, and the propane tanks can be stored over long periods of time. Another benefit of these generators is that they eliminate human error, like a gasoline spill during refilling, as the user never has to come in contact with the gas itself. The types of propane generators available on the market include these:

  • Portable propane generators
  • Propane home generators
  • Propane gas generators
  • Propane conversion generators
  • Natural gas propane generators

Portable generators-Portable generators are just as the name implies, easily movable from one place to another. These machines are often used on construction sites or for satisfying short-term electricity needs. Portable generators typically fall under these three wattage categories:

750 to 3,500 watts-This size generator is ideal for camping or for producing enough electricity for operating a few essential electrical components in the home.
4,000 to 8,000 watts-This size generator is suitable for providing temporary emergency power to a 2,500- to 3,000-square-foot home (depending on the electrical demand).
10,000 to 17,500 watts-This size portable generator is suitable to be used as an electrical backup for most homes.
Portable generators are available in gas, propane and diesel models, and some feature an inverter for protecting sensitive electronic equipment from power surges.

Watt generators-Generators are rated by their wattage output, so choosing one means you should have an idea of how much electricity you need to get by. Typical home use generators fall within the following wattage ratings:

  • 1,000 watts
  • 2,000 watts
  • 3,000 watts
  • 5,000 watts
  • 6,000 watts

These generators are typically for temporary emergency use and not designed to power every electrical component in the home. For instance, air conditioning units require 30,000 surge watts to start, so a much larger, industrial-sized generator would be needed to power a home with a running air conditioner.

Industrial generators-Industrial generators are significantly larger and more powerful than portable models with wattage outputs exceeding 50,000 watts. They can be fueled by gas, propane or natural gas, and many are available as standby generators, which mean they will automatically start in the event of a power outage.

Standby generators-A standby generator is sometimes called an emergency generator or an automatic start generator, as this type starts generating electricity immediately upon a power outage. When the electricity is restored, the generator automatically turns off and goes back into standby mode until it is needed again. The most common type of standby generator is powered by natural gas and features a bank of batteries to start the generator.

Inverter generators-A generator that has a built-in inverter is necessary if you have delicate electronics in the home that can be damaged by powerful voltage spikes or dips. The inverter balances out the voltage and helps to reduce line distortion. The engine on inverter generators also adjusts to the load demands, so when very little electricity is being used, the generator is virtually silent. This also helps to make inverter generators more fuel efficient than other types of generators.

Starting Wattage vs. Running Wattage

Every electrical component in your home has a starting wattage and a running wattage. The starting wattage is the amount of electricity needed to start the appliance or device, while the running wattage is what's needed to keep it running. These numbers can often differ quite severely. For instance, a refrigerator may have a running wattage of 1,200 watts, but it requires 2,400 watts to start the compressor. Likewise, a whole-house AC unit can have a running wattage of 15,000 watts, but double that amount is needed to start the appliance. When sizing your generator, it's very important to know both of these numbers for each of the items you need to have powered in the event of a power outage.

How Much Generator Do You Need?

  1. Make a list of all the electrical items you need to have powered by the generator.
  2. Check the identification plate or owner's manual for each device to see what the starting and running wattages are.
  3. Add up both individual sets of figures.
  4. If the appliance's power consumption is rated only in amperes, use the following equation to convert it to watts: # of Amperes x Voltage = Watts

The generator that will best suit your needs is one that can handle both the running wattage and the starting wattage of all your electrical components if they all turned on together at the same time. For instance, if the total running wattage of your items is 2,250 watts and the total starting wattage for the components is 3,800 watts, then those numbers will need to be rounded up to the generator that can easily handle the load, like a 4,000 watt generator.