Emergency generators: Two options
With the American power grid becoming
less reliable every year, power
outages are bound to occur more frequently
and last longer. That means
you could end up sitting in the dark,
sweating without an air conditioner,
and eating canned meals while $300 worth of food spoils in
your freezer. Meanwhile, your basement could flood since the
sump pump is now worthless—and your kids could go crazy
without a TV or computer.
Power grid problems aside, we all lose electricity occasionally.
But when outages become routine, leaving you without electricity
for days on end, it’s time to take action by getting a generator.
Smaller, portable generators are great for powering the
essentials, like the refrigerator and microwave, while large standby
generators can power everything in your house.
In this article, we’ll walk you through both types of generators
(portable and standby) and both ways to deliver backup power
(extension cords and subpanels). We’ll cover the pros and cons
of each system and give you an idea of prices.
Photo courtesy of Briggs & Stratton
Photo courtesy of Briggs & Stratton
Two Types of Generators, Two Very Different Costs
When the power goes out, you have to start up a
gas-powered portable generator and plug it into
your appliances or a subpanel. Portable generators
cost $500 to $1,500 depending on power output.
These generators are powered by natural gas or
propane and start automatically during power outages.
Prices start at $5,000 for a 7,000-watt unit,
How to determine what size generator you need
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Add up your power needs
Estimate your power needs before you
shop for a generator. Look for a label on
each appliance that you want to power
during an electrical outage. Add up the
watts to determine the generator size
Your first step in adding backup power is
deciding what you need (or want) to keep
running when the electricity goes out.
This determines the size (wattage) of the
generator you’ll need.
Walk through the house and make a list
of everything you want to power during
an outage. Look for a label on each appliance
(they have to have one) that contains
information such as wattage, model number
and the year it was made (photo). Some labels are right inside the
door on appliances; others are on the
back, so you have to pull the appliance
away from the wall. Write down the item
and how much wattage it uses. Be sure to
include essential items, like refrigerators,
freezers, a well pump if you have one, and
a sump pump if your basement could
flood. You can go a few hours or even days
without an oven (use the microwave
instead) and an air conditioner—they use
a lot of power and would require you to
buy a much bigger generator.
Add together the items’ wattages, then
multiply that number by 1.5 (appliances
need the extra power to start up). That’s
the minimum wattage needed for your
Microwave: 600 to 1,200 watts
Refrigerator: 700 to 1,200 watts
Freezer: 500 to 1,200 watts
Washing machine: 1,200 watts
1/3-hp sump pump: 800 watts
Television: 300 watts
Laptop computer: 250 watts
10,000-Btu air conditioner: 1,500 watts
Option 1: Plug-in generators
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A portable generator
A portable generator with extension cords is the simplest and least
expensive backup power system. Keep the generator at least 10 ft.
from your house to avoid carbon monoxide poisoning.
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A twist-lock extension cord
Use a heavy-duty, twist-lock extension
cord to plug into the inlet that's connected
to your subpanel. The special
ends keep the cord from pulling loose.
Some generators come with a twist-lock
The most basic method of supplying
backup power is running a portable generator
in your yard, then plugging in
extension cords that plug into your appliances.
It’s also the least expensive solution
since you don’t need to hire an electrician
to install a subpanel. The downside is you
have to run extension cords everywhere
you want power and you’re limited to how
many things you can plug in at once (most
generators have either two or four outlets).
You also have to start and maintain
When the power goes out, place the
generator on a flat surface outside, at least
10 ft. from the house. Don’t set it under
awnings, canopies or carports, or inside
the house or garage. It’s absolutely critical
that you keep the generator away from
your house and especially away from
doors and windows—your life could
depend on it! More people die
from carbon monoxide
poisoning from the
gas engines on
generators than from
the disasters causing
the power outages.
Plug in a carbon monoxide
detector when using a portable generator.
It’ll alert you if generator exhaust reaches
a dangerous level inside the house.
Extension cords must be at least 14
gauge to carry adequate power. Follow the
cord’s maximum wattage rating (listed on
the cord’s label). Start up the generator,
then plug in the extension cords (photo
above). Be careful not to overload the
generator by plugging in high-wattage
appliances that you didn’t plan for. It’ll
trip the breaker or blow a fuse on the generator,
or damage the appliance motors.
Portable generators range in price from
$500 for a 3,250-watt unit to $1,500 for a
10,000-watt unit. Options include wheels
(get them—generators are very heavy to
lift) and electric (key) starts rather than
pull-starts. Consider how long the generator
can run on a tank of gas. Some run just
a few hours, so you’ll have to get up in the
middle of the night to add fuel. Others
have 16-gallon fuel tanks that can run up
to 10 hours.
Figure A: Portable generator with transfer switch panel
A Manual Transfer Switch Panel Makes Portable Power More Convenient
To use a portable generator without the hassle of running extension
cords, hire an electrician to install a manual transfer switch subpanel off
your main circuit panel and install a dedicated inlet to power the subpanel
(installing the subpanel is complex; not a DIY project). This setup gives
you the advantage of powering entire circuits in the house, not just individual
appliances. The drawback is you still have to start and maintain
the gas-powered generator. And unless you buy a large generator
(they’re available with more than 15,000 watts), you’re still limited in
what you can power.
Before calling an electrician to add the subpanel, choose what you
want to power during an outage. It’s worth including a circuit that’ll let
you run your TV, computer and a lamp, especially if you lose power for
days at a time, so you can keep everyone entertained. Plus, these electronic
devices don’t require a lot of wattage. The circuits you want powered
will be moved from your main circuit panel to your subpanel, so
they’ll run when you have normal power and when you lose electricity
and hook up the generator. Expect to pay $200 for materials and at least
$500 for an electrician to install the subpanel and special inlet.
During a power outage, run a cord from the generator to the inlet, flip
a manual transfer switch on the subpanel, and all the designated circuits
will have power. Choose a heavy-duty extension cord (photo above left)
with twist-lock ends (generators have receptacles for these ends) that
stay in place once they’re plugged into the generator and inlet. Be sure to keep the generator at least 10 ft. from the house.
Don't attach a second male end to
a power cord, then run it from the
generator to a wall outlet to power
a circuit (yes, people have done
this). This may seem like a clever
way to run power through your
home's wiring system, but the electricity
will run back through the circuit
breaker panel and out to the
utility lines, which can kill service
personnel working on the lines,
even if they’re miles away.
Option 2: Standby generators
Standby generators automatically turn
on when the power goes out—you don’t
have to do a thing. This is the best
option if you frequently lose electricity
and want to keep all or most of your
appliances running. Most standby generators
are powerful enough to run a
central air conditioner, kitchen appliances
and other large items—simultaneously.
They’re also quieter than portable
generators and you don’t need to worry
about running cords or storing gasoline.
The drawback is the price. You’ll need to
have the generator, transfer switch and
subpanel professionally installed.
A transfer switch constantly monitors
power. If you lose electricity, it starts the
generator automatically—even if you’re
not home. When power is restored, the
transfer switch shuts off the generator.
Standby generators connect to your
home’s fuel supply (natural gas or
propane). If you don’t already have one of
these fuel lines coming into the house,
install a propane tank.
Standby generators range from $5,000
for a 7,000-watt unit to more than
$15,000 for a 30,000-watt unit (installation
included). Home centers carry a limited
selection of portable generators (but
usually no standby units). Larger sizes and
standby units are usually available
through special order or from the manufacturer.
Figure B: Standby generator system
Standby Generator System
Standby generators run off your home's natural gas supply or a propane tank,
which can be underground. The transfer switch automatically starts the generator,
which powers the circuits in the subpanel.