Introduction to Portable Generators

If you are in the market for a generator, chances are you’re thinking of a portable-type to supply remote power or to act as a backup in case of power outages.

But what kind to buy? There are many generator options out there, and they can be powered by various types of fuel.

Portable generators are classified according to their use: residential, professional, and RV.

Residential

Residential portable generators tend to be small to mid-sized units ranging from 1,000 watts to 8,000 watts. These are primarily used for backup power and occasional portable power needs.

Professional

Professional-grade portable generators are mid to large sized units ranging from 3,000 to over 18,000 watts. These models are often used on jobsites.

RV

RV generators are small to mid-sized, with wattages from 1,000 to 6,000. These usually include an RV receptacle or an adapter and are for outdoor recreational uses.

Diesel

Diesel generators require less maintenance and are more efficient than other fuel types. They are typically preferred by industry for their efficiency and low maintenance.

Most diesel engines provide more horsepower per gallon of fuel than comparable gas-powered generators. They can also run for years without maintenance.

Although diesel generators have a reputation for being more durable than gas, if they are not run regularly they may be more prone to breaking down.

Diesel generators are more expensive than comparable gas models.

Also be aware that major power outages also affect local gas stations, so it may be difficult to refuel. There could also be fuel shortages due to high demand in your area.

Diesel is the most efficient of generator fuels, offering 138,700 BTUs per gallon of fuel. To get an idea of what that means, it takes 6,000 to 12,800 BTUs per hour to heat the average-sized room in a cold climate.

Gasoline

The benefits of gasoline-powered generators include a readily available fuel source and a low sticker price.

The drawbacks include a shorter run time than with a direct fuel line, meaning you might have to refuel the tank in less-than-ideal conditions.

Also, gasoline may be as difficult to acquire as diesel in case of a power outage or natural disaster.

Experts recommend that gas-powered generators that are to be used on a regular basis be the 1800 rather than the 3600 RPM models. While 3600s are OK for occasional use, any long-term applications require the extra durability and quietness that lower RPMs provide. Some generators are able to switch between 1800 and 3600 to provide for applications such as welding.

When shopping, be aware that a gas generator running without a load is going to be much quieter than one being heavily used.

Gas generators generally require more upkeep and care than other fuel models.

Also, gas-powered generators are notoriously over-rated by their manufacturers. If you do decide to go gas, invest in the highest wattage you can afford. You need to be sure the machine is up to the tasks you’ll be asking from it.

Gas is slightly more dangerous to store than diesel, as it has a lower flash point temperature.

Gasoline is less efficient than diesel, offering 125,000 BTUs per gallon.

Propane

Liquid petroleum gas (LPG), or propane, requires a propane tank that is hooked up the generator. You can use small, portable types like barbeque tanks, or larger, stationary units that require trucks to refill. The tank will need to be periodically refilled depending on the size of the tank and the size and use of your generator. Propane has an almost unlimited shelf life, so unlike gasoline and diesel, you don’t need to worry about your fuel going bad.

Propane is less efficient than gasoline, offering 91,300 BTUs per gallon.

Natural gas

Many models of residential generators are fueled by natural gas.

One of the advantages of natural gas is that if you have an existing line, a generator can be hooked directly into it, removing the problem of running out of fuel or having to constantly refill the tank.

One thing to be aware of when you choose your natural gas generator model is its required gas pressure. Check the standard delivery pressure of the natural gas coming into your home. If the required pressure of the generator is greater than what comes through the gas lines to your home, the generator may not work.

Another possible problem to be aware of with natural gas is that if there is a major disaster, natural gas supplies may be interrupted or turned off for safety.

Natural gas is the least efficient of the generator fuels, offering 90,800 BTUs per gallon.

Multi-fuel Generators

If you are concerned about convenience or fuel availability, there are bi- and tri-fueled generators. These machines can switch between different types of fuel with relative ease. Typically these use gasoline, natural gas, and/or LPG.

Your wattage rating will drop as you switch from gasoline to LPG, and drop again as you switch to natural gas.

Multi-fuel models are more expensive than basic ones. Some models allow you to switch between fuels without powering down the generator, and some do not.

Research your electrical needs to determine the type of generator you need.

Be sure to look for wattages and noise ratings on generators before you buy.

Consider price, availability, and storage to decide what kind of fuel source is best for you.

It’s a good idea to ask your neighbors what kinds of successes and failures they have had with various makes and models.

Finally, buy the largest generator your budget can handle. No one has ever reported regretting having more power than necessary, but plenty have been short when they needed it most.

Once you are armed with plenty of information, you can buy a new generator with security and confidence.