- UPS - UNINTERRUPTIBLE POWER SUPPLY

Compare Generators with UPS

Information on Meter-based Surge Suppressor
and Back-up Power for the Whole House

UPS devices are an alternative to fuel-powered generators.  The UPS consists of a battery set (typically two 12-volt batteries), a charging system, and an inverter to convert stored DC power to AC power. The UPS most commonly has been used for computers or other electronic equipment that must not lose power at all. A UPS "senses" when power supplied by the electric utility is being lost, and then provides the energy to keep the equipment running. If a UPS becomes discharged, the batteries can be connected to an automobile charging system and brought back to full power.  

WHOLE HOUSE UPS SYSTEM

A new breed of UPS now on the market performs this same function for larger home systems, such as refrigerators, water pumps, furnaces and lighting.  This whole-house system is controlled by computer circuits that monitor the status of power provided by the utility.  If the power fails, the controller waits briefly (you set the time) before automatically switching over to battery storage.  The delay is to avoid making the jump to backup power when the grid is just experiencing a momentary loss of power, not a full-scale interruption.  The battery system remains active until power from the grid is fully returned.  In the case of an unusually prolonged outage, battery power can probably sustain a house for a couple of days, depending on the electric load it is being asked to supply.  If more storage is required, additional batteries can be easily added.  When power returns, the device then transfers automatically back to grid power, and the charger replenishes the batteries.  

A UPS is generally more expensive to buy than a generator, but less expensive and easier to operate and maintain. Plus, the convenience of having no moving parts, the ability to provide backup power without any owner action, and the absence of noise and combustion pollution, may give significant advantage to whole house UPS compared to generators.  Following is an example of the cost to purchase a UPS versus a generator:

UPS:  A 1999 catalog lists a whole-house UPS 2,500-watt model, which includes an automatic transfer switch, for $3,100.

Generator:  A 2,500-watt, 5.5 horsepower gas generator lists for $1,055.  This unit has an electric start.  This same catalog lists a transfer switch capable of up to a 5,000-watt load at $270.

Installation for both generators and whole-house battery systems by a qualified electrician would likely be similar, as both involve siting the alternative electric source where appropriate, and wiring it into the home's electrical system and service panel.  

For more information about UPS systems, visit www.traceengineering.com. To order UPS systems from Washington Electric Co-op, check out UPS Products in the Washington Electric Co-op online store.