While it’s too late for this storm (we’re currently awaiting the full force of hurricane Sandy), I thought the current conditions were appropriate for a post on generators while waiting for trees to fall on the power lines and send our house into darkness…

If you’re thinking about getting a generator, you’ve got some big decisions to make. Let’s start by keeping this simple, then later I’ll review the technical details.

Decision 1: automatic or manual – the $10k question

A typical portable generator

Manual Generators

If you’re only worried about keeping the refrigerator running and having a few lights, you can get by with a portable generator. For under a thousand dollars, you can buy a generator that’s powerful enough to run pretty much all your essential, plug-in appliances and lights.


  • Inexpensive
  • Available on-line or at your local hardware store
  • No installation required
  • Powerful enough to run refrigerator/freezer, lights, and other 110v plug-in devices.


  • Manual operation – you have to take it out, plug things in, and start it up
  • Frequent refilling of gas tank – forget to fill and your house goes dark
  • Requires gasoline storage – gas is very volatile and you’ll need many gallons to run a generator for more than a couple hours
  • Not intended to run long – the cheap engines on low cost portable generators are not very durable.
  • Potentially dangerous – during a nasty storm, people are tempted to stay indoors and run generators in enclosed spaces like the garage. Carbon monoxide and fire hazards can kill.
  • Will not run central air, heat pumps or other devices that are “hard wired”
  • Requires manual maintenance – engines should be run monthly to keep them “healthy” and ensure that they actually work when you need them.
  • Only works if you’re home to turn them on. If you need to run a sump or other critical items in your home, this is not for you!
  • Noisy
  • Poor power quality – lights will flicker. Not good for many electronics.

Overall, portable generators are fine for emergency use for a few lights and the fridge when you’re home to start it up and plug things in. But if you need something more reliable and convenient, you should look at an automatic generator.

Portable generation system with transfer switch

Some people will use portable generators connected to electrical “transfer switch” (more on this later) that’s wired to their main circuit breaker panel. This allows them to use a low-cost generator more conveniently. It still has most of the cons of the manual generator but provides more convenience – you just wheel it out, plug in a giant extension cord to the transfer switch, power it up and flip the switch.


  • Still relatively inexpensive
  • With a suitable generator, allows operation of 240v appliance like central air and well pump
  • Increased convenience since home’s circuits are wired directly to transfer switch


  • Almost all of the cons listed above
  • Requires an electrician to install the transfer switch
  • Transfer switch and electrician adds cost to system – another $1,000-$2,000
  • Still requires manually filling gas tank and storing fuel

The portable generator with a transfer switch is a good compromise and is the route I first took. It allowed me to wire up key circuits (the water well, heating system, some lights, refrigerator, computers so that I’d be able to keep working during an outage. I used an inexpensive 7,000 Watt diesel generator and it always had ample capacity. Note that I did NOT connect the air conditioner, pool pumps and other big power hogs to this as I considered them non-essential and they would have put a much heavier load on the generator.

This all worked fine up to a point. However, I still had to wheel it out of the garage, plug it in, turn it on, and flip the switches. If I wasn’t at home, someone unfamiliar with the unit and its operation would not have been able to get power. In fact, this is what happened in a big storm – we were away from home and power was knocked out for several days. Our house-sitter was stranded in the cold and had to seek refuge elsewhere. Even worse, the many power surges from wires going down ended up frying about $20,000 worth of appliances and heat pumps. We’re just lucky that the pipes didn’t freeze causing more damage!

20 kilo-Watt Whole House Generator

Automatic generators

By “automatic generators”, I’m referring to generators that are permanently mounted and wired into your home’s electrical system. At a minimum, they contain an “automatic transfer switch” that turns on the generator and switches power between the utility and the generator as needed.


  • Automatic operation – turns on when utility power is lost
  • Hard wired into home’s electrical panel – no extension cords required
  • Available in large enough sized to run *everything* in your home
  • Usually propane or natural gas powered – allows much longer runtimes (days or weeks). Also more reliable because propane/NG has less stability/residue problems as gasoline/diesel fuel
  • Reduced manual maintenance – most have electronics that run the generator periodically
  • Increased reliability – these units are designed for longer operation so they are generally more durable and longer lived
  • Can power the entire house – instead of just a few circuits, if you get a large enough generator and an appropriate transfer switch, you can wire the main feed of the house to the generator giving you “normal” operation of all circuits in your home
  • Can be quieter and more attractive than portable units


  • Expensive – fairly extensive electrical work and installation required. Units themselves are also much more expensive as are the required automatic transfer switches. Typical installed cost is $10,000 – $20,000
  • Many units sold in the United States are loud, inefficient and not very durable. You have to do your homework before making a purchase

If you can afford it, this is definitely the way to go. Most people don’t want to be bothered with the manual switching and other limitations of a portable unit. Plus, as my experience proved, when you need it the most, there’s a chance that you won’t be home, leaving you with a fridge of rotten food, maybe frozen pipes and other damage to your home.

This problem is very real. In my area, many people have basements requiring automatic sump pumps. When the power goes out, even a battery backed sump won’t run long and if they don’t have a generator, the basement floods. Water cleanup and repairs can easily lead to tens of thousands of dollars.

For these reasons, after my bad experience with a manual generator, we bit the bullet and installed a whole-house automatic generator.  In our area, we don’t have natural gas, so we had to get a propane tank installed as well.

How does it work? So far so good! Every couple weeks, the unit runs its exercise schedule to keep it “happy” and healthy. The couple of times we’ve lost power this year, the unit turned on within seconds and restored our power.

However it hasn’t all been perfect. I had hoped that as soon as we had a few brown outs, the generator would turn on and disconnect the house from the utilities. Around here, when we have power outages, we also have surges from trees falling on the high voltage lines. This fries electronics. During a recent storm, this happened and we lost a couple of small electronic devices. So there’s no guarantee that our expensive new generator will prevent more problems like this! In order to prevent issues like this in the future, I plan to be more proactive and hit the switch to change to backup power *before* the power goes out. This will disconnect the house from the utilities and should prevent surges from making it to the house. Unfortunately, a large surge could still kill the part of the transfer switch still connected to the utilities, but the damage should be much more isolated.

Next article….

In the next post, I’ll discuss some of the nitty-gritty details you’ll want to think about if you decide to buy a generator.


4 thoughts on “Generators

  1. From my experience over the last 10 years, it is best to have two generators. And before you do anything, work on energy conservation (LEDs, LED TVs, newer fridge). Get a smaller fuel-efficient “inverter-generator” in the 2000-3000 watt range for the base loads (lights, wood stove fan or furnace, TV for news). Run that 24/7 and you’ll still only need around 3 gallons/day. . Then if you have larger loads, like an electric water heater or well pump, get a cheap contractor screamer in the 6000-8000 watt range. Only use that to power the big loads which means you’ll only need it 1-2 hours a day for showers and gathering enough water to drink and wash dishes for the next 24 hours. It will need about a gallon per hour.

    In a major emergency when gas may not be available for weeks, you can run the smaller generator for 1 hour on, 4-6 hours off, and even go an entire 8 hour sleep shift with it off. That will be enough to keep fridges/freezers cold and if you are using a furnace, enough time to keep the house temperature out of the danger zone (to prevent frozen pipes). That will stretch your fuel supply 4-6 times longer.

    While LP lasts a long time, larger whole-house LP/NG generators use a LOT of fuel and so you need to keep a LOT of fuel around. It can be 10 times more expensive to run both in fuel cost and amount of fuel used. If you think you’ll rely on NG (if it is available) remember that a major emergency will likely take away your NG supply, too. Think major California quakes, for instance.

    • That’s great advice for people capable of the DIY approach. The small generators can sip fuel much better than the giant, whole-house units. The most popular brand in particular can cost a couple hundred dollars a day to run.

      I started out with a modest generator and a manual transfer switch for key circuits. The disadvantages I found however had me convert to a Cummins whole-house generator.

      • I was the only one in the household who could run it, even with instructions etc.
      • It required refilling on a regular basis – not great during a blizzard
      • It had to be manually connected and turned on so if we weren’t home, the house was in danger of freezing

      After a couple of long outages, we decided that the expense was worth it for the convenience and safety.

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