Choosing the Right Generator

At the other end of the spectrum are less expensive generators with basic engines, no-frills electronics and less than optimal mufflers. These are worth consideration if you’ll only be powering large, simple electrical items such as cooking appliances, water pumps or basic power tools.

So how do you tell the difference between premium-quality and economy generators? Engine design is one way. The most durable generator engines have overhead valves and commercial-duty chrome or cast-iron cylinder sleeves. Economy models have side valves and aluminum cylinders.

Prices reflect quality, too; top-of-the-line generators cost about two or three times as much as economy models for a given wattage output.

The right fuel

Regardless of the amount and quality of power you need, there’s also the question of fuel type. Most portable generators run on gasoline, but there are advantages to propane- and diesel-fueled models, too.

Propane (also called liquefied petroleum gas or LPG) is more expensive than other fuel options when you buy it in small tanks like those used with an outdoor grill. But it’s also more chemically stable than gasoline or diesel. Ordinary gasoline becomes significantly less flammable after several months of storage as key chemicals break down or evaporate. Diesel fuel also is susceptible to degradation by fungal growth. You can expect two years of reliable shelf life by adding a conditioner to gas or diesel fuel, but LPG never goes stale, so an LPG system is worth considering if your generator will be used for emergency backup only. But, understand that what you gain in fuel stability, you lose in generator portability.

Diesel engines are traditionally found only on large, stationary generators, but that’s starting to change. Smaller diesel systems in the 4,000-watt range are now appearing on the market. Diesel engines are harder to start and usually cost more than comparable gasoline motors, but they last longer, especially for continuous use.

Got a tractor? A whole range of PTO-powered (Power Take Off) generators are available, most for medium and large power output. These units aren’t usually designed to put out the kind of clean (regular) power required by sensitive home electronics. Generator systems also can be installed onto engines in cars and trucks, either under the hood or attached to a PTO. It’s not always a simple installation, but it does offer relatively large power output, quiet operation and portability.

Power delivery

You can get power from your generator to the place you need it in two ways. Extension cords are easy to use, but limited. You have to run them from outside to indoors, and even then you can only energize items that have a plug-in cord. But if you have a generator that puts out 3,500 watts or more, it’s worth creating a connection directly to your household wiring so nearly everything requiring electricity in your home can be used (at least in theory). But there’s a catch: To be safe and legal, any such direct connection must pass through a transfer switch. This safety device ensures that either your home is connected to the grid or to your generator, but never to both at the same time.