Choices

 

A standby electrical generator is useful during power outages. The range of choices run from a small 1800 watt portable generator that can be used with an extension cord to power a refrigerator or freezer, or a larger 5000 to 9000 watt generator on wheels that plugs into a transfer switch connected to a limited number of household circuits, to a 18000 watt permanently connected generator capable of running the entire home.

Gen set with transfer switch, extension cord and outlet 

The cost of the small gen set used with an extension cord is less than $500.  The larger electric start sets on wheels (5000 - 9000 watts) including the cost of a transfer switch professionally installed will be in the $2000 to $3000 range for lower priced gasoline or propane fueled units. Considerably more ($7000) if you choose a Honda generator. The cost of a professionally installed 18000 watt whole house unit will be in the $11000 to $18000 range.

The right choice depends on many factors in addition to cost. How often to outages occur? How long do they typically last?  What is your tolerance for being without power?  Are you capable to pull start a small gasoline powered generator? Are you willing and capable to roll out a heavy unit and connect it to the transfer switch? How well do you tolerate noise. Are you prepared to obtain gasoline for a portable gen set?

Most outages are short lived. But, as the grid becomes more fragile and poorly maintained, having a high exposure to fallen trees and tree branches, it is likely that outages will increase in frequency and will last longer. Having power for medical devices, hot water and HVAC as well as to preserve food in refrigerators and freezers is important for outages lasting more than just a few hours.

The experience of using a small generator/inverter can be compared to “camping”—pretty much any device that can be powered through an 15 amp extension cord is available, like a refrigerator, a coffee maker, or microwave— one at a time. The larger sets on wheels are more like “glamping” in an RV—many, but not all circuits can be powered at the same time—with rather large quantities of gasoline required—about 5-7 gallons every 8-10 hours-more than what would be stored at home so regular trips to a gas station would be required. Running portable units during storms can be problematic—tent enclosures are available, but they are a bit fragile and potentially flammable. Running portable units inside a garage is dangerous—carbon monoxide and an extreme fire hazard, running beneath a combustible ceiling—they should be a considerable distance away from the home. The whole house unit provides enough power so that the outage creates little or no inconvenience in any type of weather. The larger portable units are quite noisy—inside the home, the noise could be as loud as a vacuum cleaner where the sound of a whole house unit would be about the sound of a dishwasher.

The cost of the whole house unit will vary greatly from one installer to another as well as on how complicated the installation is—the cost of running gas natural gas or propane plumbing and electric wiring can vary considerably. I have experienced a shocking quote range from $11000 to $18000 for the same exact unit installed the same way. Some installers add a substantial profit over the cost of the gen set—others pretty much provide the unit at their cost and are charging the typical electrician and plumber tradesman rates for labor and material.

A whole house generator for a condo, capable of “normal” life, running AC while doing laundry and cooking requires 18000 watts (75 amps) If running the electric dryer while the AC is running is not necessary, a smaller 14000 watt  (58 amps) generator would be sufficient. If you could do without the AC, an 11000 watt (45 amps) unit would be big enough, but generally these lower output units are not as robust and reliable as the 14KW and larger units. Capacity is determined by the amps required. The installed cost of a 14000 watt unit is about $1500 less than an 18000 unit.

It is very difficult to justify the investment required to install a whole house standby generator purely on economics. The out of pocket costs related to power outages except for those with extreme health issues is relatively low—pretty much the cost of food in freezers and refrigerators that is spoiled. And, historically, long periods of outage are rare. Finally, residual value if the condo is sold is probably significantly lower than cost. The investment is better “justified” by the price put on “convenience and comfort” as well as “peace of mind”. Like Fire Insurance—the hoped outcome is that cost is never economically justified by actual loss. Like a sophisticated security system—peace of mind that you will be “protected”. Like a built in swimming pool, it is convenient but more expensive than visiting the YMCA.  Like a Country Club membership for a golfer who plays less than 52 rounds per year or a European vacation-the luxury that you can afford. 

There are many brands that sell portable gen sets.   There are some units are are less noisy but more expensive. The major brands are Champion, Honda, Predator (Harbor Freight) and Generac. The major brands for whole house units are Generac, Kohler and Cummins. The choice of brand depends on the installer who is typically a dealer for a particular brand. Generac is the largest in terms of market share. Kohler has the most experience, making generators for more than 100 years. Kohler engines have hydraulic valve lifters and require less maintenance than most Generac units. Generac units are housed in smaller steel housings, Kohler units are housed in slightly larger aluminum, or composite for coastal high humidity regions where metal is subject to corrosion.