Having a source of electricity when the power from your utility goes down
can make a huge difference to your life.
People who depend on computers are familiar with the UPS, or uninterruptible power
supply, which is a small battery that provides emergency power until the
computer can be shut down properly. This section discusses how you can
can make electricity to run your most important appliances until your
utility company repairs the problem and restores your electric service.
Several different strategies are available to keep the current flowing to
your critical electrical appliances when the power is cut off. Basically,
the electricity can
either be in a stored form, as in a battery, or created as electricity
is needed, as in a generator where the energy stored in gasoline, natural gas,
diesel, or propane is converted into electrical energy by the generator.
Some of these strategies are, in order of increasing expense:
- Purchase a small portable generator (less than 4kW) into which you plug the appliance
- Have an electrician wire up a subpanel with your "critical loads" and
power the subpanel with a generator sized appropriately for the electrical
loads. This method requires a manual transfer switch to power up the
subpanel from the generator.
- Install an autostart generator large enough to power your whole building.
This has a singular advantage: the backup electricity automatically comes on
without any involvement from you.
- Use a combination generator-battery strategy. In this solution, an electrician
installs a subpanel with your critical loads. An inverter between the batteries
and the subpanel converts the battery power into regular household electricity
that goes to the appliances attached to the subpanel. The generator is used
to recharge the batteries as needed.
- Install a solar-charged bank of batteries. The phtovoltaic modules that convert
sunlight into electricity store the electricity in the batteries. A charge controller
controls the current going into the batteries. When they are full, charging stops since
you do not want to overcharge the batteries. A disadvantage is that the batteries cannot
be charged at night, so the battery bank must be large enough to supply
all electrical needs overnight and in overcast conditions when the
solar panels do not produce much power.
Electric generators can be found in all sizes and prices, portable,
stationary, recoil manual start (like a lawn mower), electric manual
start, automatic starting, etc. You can find all sizes of generators
through the internet, hardware stores, or electrical supply shops.
Some notes on safety:
- Generators are designed to be used outside or in a
well-ventilated area. The exhaust gases can be deadly in
- Use a licensed electrician for all electrical connections to
ensure they meet all local and national safety codes.
- Battery banks must be kept in a ventilated enclosure.