Emergency Standby Power
As you can imagine, computer systems aren't too happy to lose power without being properly shut down first. Non-laptop computers have no internal battery* so they'll unceremoniously power off even if the power blinks for just a fraction of a second. Usually they'll restart with no problem. But if the computer was busy updating critical files or structures on the hard drive (or SSD) at the exact time of power failure, then it may not restart. That doesn't mean your data was lost, but if you aren't a techie you may need to call a pro to get it running again.
* There is a small button cell the size of a US quarter for maintaining the clock, that is all. It doesn't provide running power.
These brief power outages, lasting up to a few seconds, are common in most areas even during nice weather. I'm sure you can recall seeing this a few times in your home or business.
You can avoid this insult to your computer(s) by installing a UPS (Uninterruptible Power Supply) for your computer. A UPS is about the size of a shoe box and costs around $60 to $120 depending on size. It contains a battery that will immediately start power flow to your computer, preventing it from losing power in the event of a mains outage. And when the mains are working again, the battery is recharged. It's maintenance free.
Depending on various factors, the battery will provide computer power from 10 minutes up to maybe an hour or so. The purpose of a UPS isn't so you can continue working all day. It's simply intended to let you save your work, close your files, and properly turn off your computer. Laptops don't need a UPS -- they have a battery already built-in.
Weather related outages
Sometimes you'll lose power due to adverse weather, like the hurricanes that have recently whacked Texas and Florida (where I live). A UPS will protect your computer against the quickie power outages that often precede a storm but does nothing for longer term outages and for powering other things in your home.
For that, you'll need a generator if you want power during the powerless days (or weeks!) following a big storm. Choosing the right generator technology and correctly sizing it requires considerable expertise. e.g. Understanding Volts, Amps and Watts, wire gauges (that's the thickness of the cords), cord lengths, motor starting current, and other factors. If you aren't savvy about such electrical concepts then you'll need help making the right decisions. This isn't something to guess about. Properly choosing and sizing a generator is pretty serious and important.
In this article, I'll discuss the major considerations to help you decide which technologies might be best.
First question to ask: Must you have whole-house power as though the power never went out? Or can you get along with just a few select appliances like the refrigerator, microwave, a few lights, TV, and maybe a window-unit air conditioner for a bedroom?
Whole house systems
For a whole-house system, I'd recommend a propane-fueled generator. Why propane? Propane doesn't go bad like gasoline does and you can bury a 250 or 500 gallon tank and have propane delivered. That's enough fuel to run your generator for a couple of weeks or even longer if you exercise some discretion.
If you have natural gas in your neighborhood then you can use that instead. Natural gas usually flows even if there's a power outage. But if you want to be absolutely positive that fuel is available, then propane is the answer.
A typical 2,500 sq/ft home needs a minimum of 12kW of power if you want to live as though there were no power outage. You might not be able to run all your high current appliances simultaneously (stove, oven, air conditioner, water heater, clothes dryer) but other than that, you can live life as normal.
Whole-house generator systems (optionally) come on automatically when there's an outage (after a short delay), they self-exercise periodically to stay in running shape, are quiet, and fairly low in maintenance (annual oil change, generally)
Expect such systems to cost around $12 to $15,000 for a typical 2,500 sq/ft home, depending on size of tank, capacity of generator, and other factors.
If spending in the low five figures isn't appealing for something you could go years without needing then you might consider using a portable generator. But before you buy a portable gen set, there's some things you need to know.
Most of the generators you see at Home Depot, Lowes, etc. aren't really designed to provide home-use electricity for storm-related power outages. They are designed for commercial and industrial use, powering heavy tools and such, often on job sites that lack electrical power. These job site generators are fuel hogs, they are loud, they are heavy, and they often produce dirty electricity that may not be suitable for the sensitive electronics that we all have in our homes.
Feeding these gen sets is problematic as well. These gen sets can consume 5 to 10 gallons of fuel per day. They consume a little less with lighter loads but not by much. These generators have constant-speed engines operating around 3,600 RPM or so. So even with a lighter load (less turning resistance on the alternator shaft) these engines still drink a lot of gasoline. Builders and commercial users can easily bring a hundred or more gallons of gasoline to a job site to feed these beasts so they don't care about efficiency that much. There's no way the average home owner can transport or store that much fuel. Prices are attractive for these units so people snap them up without understanding these downsides.
And because these things are loud as hell, you're going to piss off your neighbors. While you are enjoying electrical power, possibly with air-conditioning and windows closed, your generator-less neighbors probably have their windows open. So not only are they suffering while you sit in comfort watching TV, but they are listening to your loud-ass generator and smelling its exhaust! Not nice, especially at night when people need to sleep, which is already difficult enough without AC.
A newer breed of inverter generators are designed more for home and RV power needs. These units are lighter in weight, are more gasoline efficient, very quiet, and produce much cleaner electricity for sensitive electronics. A 2 kW (2,000 watts) unit can run a refrigerator, TV, and maybe a small window unit AC for your bedroom (not your central air). And by alternating between appliances, you can still utilize a wide range of appliances albeit only two or three at a time. e.g. Need to run a 1,600 watt microwave or toaster over? OK, unplug the fridge for 15 minutes. Or you can buy a 3 kW inverter gen set and run 3-5 things simultaneously.
These inverter gen sets can run for 6 to 10 hours on one gallon of gasoline at reduced load. That's because these gen sets reduce their engine speed as load dictates.
But won't my fridge make the generator work harder? Most refrigerators have a fairly light duty cycle. That is, the compressor is usually not running - especially if you keep it full and don't open the doors too often. When measured over the course of a day, the total power consumed isn't that high. And today's refrigerators are more efficient than ever.
Honda is the leading manufacturer of high quality inverter generators. They cost about twice as much but so what? When you need your generator the most, then you want the best.
Models I like are the EU2000 (1,600 watts running, 2,000 watts surge) which can by carried with one hand and EU3000 (2,800 watts running, 3,000 watts surge). Both of these models can be run in parallel (2x EU2000 or 2x EU3000) which doubles the running power output to 3,200 and 5,600 watts respectively. There are other brands with similar features that get decent reviews as well. But Honda seems to get the best reviews.
The EU2000 runs about $1,000 and the EU3000 is about $2,000.
Even efficient generators can use a lot of gasoline if the power is out for a long time so you may want to have 15 or 20 gallons on hand. Any more than that gets to be a real hassle.
Gasoline doesn't store very well long term, especially ethanol blends, so you'll want to rotate your inventory seasonally. If your primary concern is having standby power during hurricane season then I recommend filling your portable tanks when the first hurricane of the season is about 7 days out and is tracking toward your area. That's far enough ahead of time that most people aren't yet making their (usually) mad-rush last minute preparations. Then after hurricane seasons ends, rotate out any unused gasoline by filling your own car's gas tank.
I recommend using ethanol-free "E0" gasoline. Not only is E0 better for your generator, it also lasts longer while stored because it contains no water-absorbing alcohol. There are usually a couple of gas stations in most areas that sell E0 fuel.
When empty, leave the lid open, turn upside down, and let the tank completely dry out for a few hours. This will encourage any trace vapors to escape. Gasoline vapor is heavier than air, so flipping the tank upside-down tank helps vapors escape.
There's lots of portable gasoline tank designs. In my opinion, the NATO-style 20L Jerry cans are the best storage containers.
Even newer are the so-called "solar generators". I just can't say enough bad things about how this technology is marketed. Why bad? Because their marketing heavily implies they are designed for use in place of regular gas powered generators, such as for use during weather-related outages. Problem is, they don't provide much power per charge. And recharging takes a very long time. Unless you understand the same Volts, Amps, and Wattages needed to properly size a regular generator, then you may not understand why these solar generators are so woefully inadequate for emergency power needs.
These solar generators are simply a big battery connected to a voltage inverter* that you can recharge using a separate solar panel. Some models use a lead-acid battery, the same type of battery in your car, and others use more compact lithium batteries. But the idea is exactly the same. Batteries are far less energy dense than gasoline and therefore provide far less power.
* A voltage inverter converts battery power to 120 VAC "wall plug" power.
For example, the Goal Zero Yeti 1250 provides less electricity per charge than 1/4 gallon of gasoline in a regular inverter generator. That's less than one quart of gasoline! Stated another way, a five gallon can of gasoline will produce a minimum of 25 times more electricity in an inverter generator than a fully charged Yeti 1250.
After being discharged, the Yeti will require 25+ hours of full and direct sunlight on the solar panels to recharge. Direct means you must adjust the panels every hour or so to be pointing squarely toward the sun. In real practice, that charging time can easily hit 50+ hours. And since we have only about 8 hours of strong useable sunlight per day (and that's assuming no cloud cover), then it'll take 3 days, minimum, to recharge using a solar array. Not very convenient to be sure.
How long will the Yeti 1250 run on a charge? You could power a small one-room window AC for maybe two hours. Then you're facing that 25+ hour solar recharge. Or you could power an energy efficient refrigerator for 8 to 10 hours or so, max, before needing to recharge.
The Yeti might be fine for a day or two of camping where electricity needs are modest. You can let it charge during the day and use it a few hours in the evening. Another good use might be for low powered yet critical medical devices, such as a CPAP or similar device.
But please understand, portable battery-based solar "generators" like the Yeti are absolutely no substitute for a traditionally fueled generator, especially for a homeowner needing to power a refrigerator and other small appliances for what could be an extended weather-related outage.