Ask the Builder: Know energy needs before buying generator
DEAR TIM: I’ve had it with power outages here at my home, and I’ve decided to get an electric generator. I’ve got several complicating issues. For starters, my budget is tight. Second, I want this generator to be multi-purpose and want to take it on family picnics and camping trips. The generator needs to be quiet. What are my options? Can I satisfy all of my wishes and have clean power that won’t hurt my sensitive electronic devices? – Kathleen K., Boulder, Colorado
DEAR KATHLEEN: I’ve got great news for you. You can get a new portable generator that will satisfy all your requirements! What’s more, if you lug in multiple bags of groceries on a routine basis, I believe you’ll be able to carry one of the generators a short distance with only moderate effort on your part.
As with many things, advancements in technology and micro computers have allowed manufacturers to produce small generators that produce stable and clean alternating current using an inverter inside the machine. Most new portable generators have an onboard computer that converts the direct current from the generator to a very stable alternating current that will not harm your sensitive electronics and appliances.
I know this for a fact because in the past two weeks I tested two different portable generators using an oscilloscope to measure the quality of the electricity being produced by the generators. Guess what? Both machines created a more perfect sine wave on the scope than the electricity coming into my home from my local utility.
Here’s the scoop on the portable generators. Size does matter. The bigger the generator, and all its combined parts, the more power it can produce. If you want portability, meaning a generator you can carry like a five-gallon pail of drywall compound, then you sacrifice total power output.
The generators I tested weigh about the same as a pail of drywall compound and produce 2,000 watts of power. That may seem like a lot of power, but it’s not when you think about the giant standby generator I have next to my garage. This generator comes on automatically if the power fails at my house and will produce 17,000 watts. You can buy generators that produce far more power than that if you desire. My standby generator weighs hundreds and hundreds of pounds.
Since your budget is tight, you’ll probably be able to get one of the 2,000-watt machines. Even though its power output is not the highest, you still can power many things with it. For example, here’s the running wattage of some common tools or appliances:
Cellphone battery charger: 25 watts
Furnace fan blower: 700 watts
Electric crock pot: 240 watts
Video game device: 40 watts
Refrigerator: 550 watts
Water well pump: 575 watts
What I love about the new portable generators is how they automatically adjust the gasoline motor speed to the power being requested by the devices you have connected. If the generator senses little need for power, then the motor runs at a lower speed, using less fuel and making less noise.
The new generators are also very quiet, even when running at full speed. When you take them on a camping trip or a picnic, you won’t have to scream to be heard in a conversation.
The issue with small generators is what’s called startup power. Certain appliances and tools have a very high starting wattage. You may have seen this in your home on occasion when a refrigerator, washing machine or air conditioner turns on. The lights in your house may momentarily dim when the electric motors in these things draw lots of power to start spinning.
A portable generator putting out only 2,000 watts can’t handle the start-up demand of many things, so you’ll have to check into that to see what you can and can’t power when your house power goes off.
You’ll discover you can use a portable generator in the event of a power outage, but you’ll be busy. You’ll only be able to power a few things at a time, so you’ll be switching out extension cords.
The portable generators have smaller fuel tanks, so if you have an extended power outage you’ll be refueling on a more frequent basis. Follow all safety guidelines when refueling a generator and NEVER operate a portable generator indoors, in a garage, near an open window, or in any other way that could result in exhaust fumes being trapped. The carbon monoxide produced by the gasoline engines can and will kill you.
Tim Carter’s columns are archived at www.AsktheBuilder.com. Need an answer? Just click the Ask Tim link on any page of the website.