How To Choose a Portable Generator


If this is your first time to purchase a portable generator for any reason, there are a number of factors that need to be considered. The following is not necessarily a comprehensive list but should at least narrow down the choices to a manageable few.

1. Will noise be a factor? It may seem a bit odd to place this as the first consideration, but it really is important. If you will be using it only in locations so remote that neighbors couldn’t even hear a shotgun going off, then it’s not a factor. If it will be used only for emergencies such as a major power outage during a hurricane, then the neighbors will most likely have other things to worry about and it’s still probably not a factor.

Conversely, if you’ll be using it as your only power source in a crowded development with neighbors packed on top of each other like sardines in a can, it most certainly is a consideration. Likewise, if you or your significant other just plain hate noise pollution (as I do), noise is a consideration.

2. How much power will be needed? This one can be tricky. For one thing, there’s a huge difference between “needed” and “wanted”. Secondly, first time users need to know that rated wattage on any portable generator out there is much greater than the realistic usage available. Pam and I try not to use much more than one quarter of the rated amount if the time of usage is going to be longer than a few seconds of surge.

3. How critical is the cost of fuel? I’ll limit the discussion of this issue to machines using gasoline as fuel–simply because we have the most experience with those–but the same question applies to generators (portable or not) powered by diesel fuel or propane. In general, the power output of the unit far outweighs the brand name on this point: Figure out the size needed first, after which it does pay to compare fuel consumption figures between makes and models capable of producing the desired output. That is, Brand A’s 5000 watt machine may use less fuel than does Brand B’s 5000 watt machine…but no matter how fuel-stingy Brand A may be, its 5000 watt machine will not be able to get by the gas pump as cheaply as any brand’s 1000 watt model.

We’ve found this power-versus-fuel-cost problem to be most easily handled by having two generators, not one, on hand at all times. The 900 watt unit runs as much as 16 hours per day and is powering the computer I’m using to write this Hub. The 5500 watt machine, which is actually an entirely different brand and cost less than the much smaller workhorse, is used only in brief bursts for brewing coffee, microwave cooking, pumping well water, and other high-wattage tasks.

4. Are sensitive electronics involved? By “sensitive electronics”, think computers. We’ve used “coarser” electrical power to run TV sets and air conditioners and just about everything else, but the personal computer–to be safe, anyway–needs the security of a “smoother” sine wave of AC current. Every good solar installation uses an inverter for just this purpose as well.

...the personal computer....needs the security of a "smoother" pure sine wave of AC current.

…the personal computer….needs the security of a “smoother” pure sine wave of AC current.

An Illustrative Example

There are way too many possible choices when you take all four parameters into consideration. It can be terrifically confusing. What’s worse, if those four factors are not studied with some serious thought, it’s quite possible to wind up spending hundreds or even thousands of dollars for a huge generator you can’t afford to fuel (on the one hand) or perhaps a wimpy thing that will burn out almost immediately from being overloaded (on the other hand).

Let’s take a look at the steps we followed and the results that…uh…resulted.

1. The noise factor. For me even more than for Pam, noise is a huge factor. I detest unnecessary background noise. With that in mind as I began searching the Internet for our “first and most important” portable generator last March (which would be used in our new digs in Cochise County, Arizona, come April), I always looked at the decibel rating. Nothing over 60 db (decibels) was even considered.

2. The power requirement factor. Having “been there before”, we figured we could get by with a small 1000 watt generator for the long-running stuff. Essentially, that amounts to one television set (including the preamp which improves antenna reception), one laptop computer (with the printer turned on only as needed), and one 60 watt incandescent bulb (we refuse to use flourescent lights). Total: Somewhere around 200 watts of “draw” after dark (when the lamp is turned on), around 140 watts during daylight hours.

[Upgrade note, October, 2013: Later on, “upgrading” with multiple TV sets and sometimes two ongoing light bulbs, we doubled that wattage requirement. Our workhorse for the past several years has been a Yamaha EF2000iS pure sine wave portable generator, rated at 1600 watts, of which we seldom use more than 400 watts or so.]

We did discover that we needed a much larger unit to power the well that was already in place. Thankfully, the man who sold us the land also came up with a 5500 watt Troy-Bilt unit (powered by a 305 cc Briggs & Stratton engine). He purchased it initially, and we are reimbursing him as we can. Yes, we believe we bought from the right gentleman! Since we are free to use it any way we choose, we fire that one up whenever we need to brew coffee (675 watt coffee maker) use the microwave (900 watt draw), etc. It is seldom on for more than 20 minutes per day, which is good in two ways: That big beastie sucks down gas pretty fast, but still not a lot with such short running times…and the engine should last just about forever.

3. The fuel factor. For our primary unit, this was absolutely crucial. I was leaving a high paying job as a truck driver during hard economic times with no employment guarantee in Arizona. As it has turned out so far, I still have not succeeded in getting hired for a new “day job” some three months after our arrival in Cochise County. (No donations, please. I am drawing my Social Security and supplementing that with writing articles on the Internet. Our land purchase is secure, and we won’t starve.)

But the point is, it’s not that difficult with a larger generator to end up either drastically limiting your times of power availabilty or paying a whole bunch for gas every month. If you’re not volunteering to subsidize the oil companies, pay attention to this factor. If we ran our 5500 watt Troy-Bilt 14 hours a day, the fuel cost alone (at 07/06/09 prices) would be running nearly $1600 per month!!!! OUCH!!!!

4. The sensitive electronics issue. I knew being able to go online “at will” was important. Although unaware that within a month or two I’d give up entirely on local job hunting and begin writing online full time, there were other needs. Various Internet searches…email…online banking…posting song videos…maintaining my poetic humor website…. Even with the right generator, I’ve already blown up one of my two precious laptops. (Not the fault of the power source; another issue entirely.)

Once all four factors were considered, the decision turned out to be no decision at all.

came down solidly on the side of one little lightweight machine in particular: The Yamaha EF1000iS. Don’t get me wrong. Yamaha does cheat a little: Though rated at 1000 watts in the online advertising, the user’s manual admits its output is really only 900 watts. But that is still enough for our immediate needs, and the lower output means it’s a real fuel sipper.

Checking this out night after night produced the following findings:

    1. Nothing else on the market was nearly as quiet. A similar Honda model came close, but no cigar. The two were comparable at higher rpm speeds, but the Yamaha’s economy switch–which allows it to run at 1/4 load at only 47 db, quieter than normal human speech–beat the pants off the Honda’s 52 db rating for the same load.

    2. Rated run time for the Yamaha was a full 12 hours on a full tank at 1/4 load. Nothing else even came close. That 12 hours is on a fuel tank capacity of only 0.66 gal. (and we do even better than that in practice), which means we’re getting by on roughly $50 to $55 worth of gas per month…not $1600!!

    3. The “i” series for both Yamaha and Honda have internal inverters as part of their technology. To state what this means in the simplest terms, electricity that goes through and inverter comes out “clean” and very safe to use for computers and other sensitive electronics. Either the Honda or the Yamaha appeared perfectly functional in this regard, but the Yamaha had already won the match on the other two points.

Besides, we’d already owned a Yamaha and really appreciated its quality and durability…not to mention that this new one only weighs 27 pounds right out of the box!

Your portable generator needs may, of course, point toward an entirely different machine than either the little Yamaha or the much heftier Troy-Bilt. With that in mind, have some fun. Take a few hours, check out a few different makes and models on the Internet and at your local stores, apply the criteria.

When you’re done, you should be able to impress the dickens out of your spouse with your newfound knowledge regarding the exact generator that is just right for you…right?

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