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My friend Jim never forgot the ice storm of ’88, when he lived without power for a couple of weeks. He recently installed a natural-gas-powered generator, which is a rather expensive insurance policy.

Ameren spoils those of us who live within its service area. Short of natural disasters, it reliably delivers power. I don’t recall a significant outage (except when we were forewarned that they were replacing lines) in almost a decade. I have a home elsewhere where the power fails almost weekly. Most of the rare outages in Champaign County last a few minutes, which is far better than internet service if you don’t live within Champaign-Urbana.

Three decades ago, power outages of under an hour rarely mattered, since refrigerators and freezers keep cold for a few hours without power. The telephone company provided its own power for phones. Today, outfitted with dozens or scores of power-hungry products, we rely far more on dependable power. Since many people replaced their landline phones with voice-over-internet-protocol phones, the phone company no longer powers those phones. While a cellphone might substitute, it only works if you keep the battery charged. You can read your Kindle or Nook in the dark, assuming you keep its battery charged.

An uninterruptible power supply provides a budget alternative to a generator for power outages under an hour. It delivers enough power to keep all of your gadgets, computers and phones running during brief outages. It also prevents data loss on your computer, which is handy if you just finished the final chapter of The Great American Novel and haven’t backed it up. Of course, Microsoft Word keeps a lagging backup, but should the power failure crash the computer, even this can be lost.

While a generator costs $2,000 to $3,000, an uninterruptible power supply costs $100 to $500, depending on the amount of power it provides and other features, such as re-creating a sine-wave that resembles what the power company sends verses a “dirtier” square wave that doesn’t work with some equipment.

Good models, when not actually replacing power during an outage, filter the incoming power, keeping the voltage within safe boundaries and providing surge protection for your equipment. On days of very high demand, sometimes the power company voltage sags, so a good UPS will compensate. On rare occasions, the voltage regulator at the power company fails and the higher voltage can damage equipment. A good UPS regulates this as well.

Buy one that is far larger than you need, and perhaps buy two — a smaller one, perhaps 850-1,000 volt-amps, for about $130, to keep your internet modem and router running (they don't draw much power), then a 1,500 VA, for about $190, for the rest of your gear.

These prices are for units that generate digital sine waves. Generally, actual wattage is about two-thirds of the volt-amp figure, based upon the design of the unit. That means a 1,500 VA unit provides about 1,000 watts for an hour. Depending upon how many devices draw upon the UPS and their power requirements, you might have a 10-minute window to save your work and shut down for an hour or more. Most power outages not caused by an areawide natural disaster darken your home for less than an hour.

APC, CyberPower and Tripp Lite dominate the UPS market. After trying all three brands, I detected little difference, although overall I prefer CyberPower. However, most still use sealed lead-acid batteries, a modified version of the kind used in cars. This gives the average unit a life expectancy of about three years. While you can purchase replacement batteries, it generally doesn’t justify the cost or effort. In many of my units, the electronics died as well as the battery. Or you could power your whole house with a Tesla PowerWall for $6,000 to $15,000.

Rich Warren, who lives in the Champaign area, is a longtime reviewer of consumer electronics. Email him at hifiguy@mchsi.com.