During a Maine winter, it’s almost a certainty that your power will go out at some point.

With gusting wind, heavy snow and the occasional paralyzing ice storm, power lines have a lot to put up with.

So looking into buying a generator to get you through prolonged power outages might be a good idea, especially if you live in a rural area with lots of trees.

And the best time to consider a generator is probably before a storm, when the strain of not having showered in three days could make it harder for you to think straight.

“One of the first things we do with a customer is get an idea of how often they lose power, and whether they travel a lot or they’ll be home when the power goes out,” said Jim Ford, assistant manager of the Home Depot store in South Portland. “That way we have an idea of what sort of generator they’ll need.”

When most Mainers think of generators, they probably think of the portable, gas-powered ones that fly off store shelves right after a big storm.

But not all of those will power your whole house. Many are just powerful enough to fire up your refrigerator, a few lights and maybe the TV, Ford said.

A permanent generator might power your whole house, but they run about $2,000 and up. A portable one that is powerful enough to run your fridge, some lights and the TV might start at under $400.

So which kind of generator is right for you? What sort of things do you need to consider before buying one?

Here are some guidelines to help you sort it out.

GOT (ENOUGH) POWER?

You’ll need to figure out what appliances you want to run during an outage, and how much power they require.

Home Depot has a handout that lists the wattage needed to run a couple dozen appliances in the home. A sump pump — crucial during a storm to get water out of your basement — needs about 1,500 watts. A refrigerator runs on 600 to 800 watts, but may take 2,200 watts or so to start up. A table lamp takes about 150 watts, while the TV takes 100 to 350.

Lowe’s has a power calculator on its website, Lowes.com. It lets you plug in the square footage of your home, and your zip code, and it gives you a range of how many watts it takes to power some of the basic appliances in your house — refrigerator, furnace fan, lighting and outlets for other small appliances. The calculator does not take into account big power users like electric hot water heaters, air conditioning units, a sump pump, or a well pump.

When you plug 1,500 square feet into the calculator in the 04106 area code (South Portland), you get a range of 7,000 to 9,000 watts.

PORTABLE OR PERMANENT

One of the biggest differences between a portable generator and a permanently installed one is how much power they put out. Most portable home generators generate somewhere between 3,500 and 5,000 watts, with some going up to 8,000 watts. Prices are usually between $400 and $700 for 5,000 watts.

Permanent generators start at around 7,000 watts, and about $1,900, and go up to 45,000-watt units that might cost $15,000.

Another big difference is the power source of the generators. Most portable generators run on gasoline, while permanent generators have to be hooked up to a propane tank or a natural gas line.

HEATING

One of the biggest concerns about losing power in the winter is losing heat. A permanent, whole-house generator, will probably have enough power to kick a heating system on, whether it’s an oil furnace or gas.

But since most oil furnaces are hard-wired into a home’s electrical system, you can’t plug them into a portable generator. However, if you have a forced hot air system or some other heat source that uses a fan, you can plug the fan in. Pellet stoves, which need electricity, can be powered by a portable generator.

SAFETY

Because portable generators run on gasoline, it is vitally important that they be used ONLY outside and never in any enclosed space, like a garage or shed. Because of the poisonous carbon monoxide they emit, they need to be out in the open and away from any windows.

Since carbon monoxide is odorless and tasteless, the Home Safety Council says that when you use a portable generator you should always have a functioning, battery-operated carbon monoxide alarm in your home.

The Home Safety Council says permanent generators are the safest way to provide your home with back-up power. First, they don’t run on gasoline. And they are usually installed for you by the seller, while the homeowner has to hook up a portable.

The other major safety concern with portable generators is the installation. Some people will try to “back feed” the generator into their house, by using certain kinds of extension cords and plugs to generate power directly into the electrical system.

This is dangerous, Ford says, because it will create live wires around your home. So power crews fixing outages will think the wires are not live when they are.

The only safe way to use a portable generator is to read the directions carefully and plug appliances into the generator the way the manual describes, using extension cords long enough to reach the generator outside.

Which is another good reason to buy a generator before an outage hits, before you become frantic.

Portable generators might be too heavy for people in ill health to move, so that’s another safety consideration.

And a final safety tip is to find a way to chain or lock up your portable generator when it’s outside, to prevent theft.

Staff Writer Ray Routhier can be contacted at 791-6454 or at:

[email protected]