Tuesday, October 13, 2015

Bugging In: Power Up

In many emergency situations, the lights will go out. Even though it is a critical part of our daily lives, the electrical grid is surprisingly fragile. Most times, the repairs are quick and everything is back on line in short order, but sometimes the system can be down for a week or even longer. In these kinds of situations, you're on your own until things get fixed.

Short-duration power losses are simple to prep for. Flashlights and candles, along with blankets and maybe a small backup generator will cover the bill. Longer durations involve larger and more complex setups, with special considerations to keep in mind

How Much Juice?
In order to determine how much power you'll need to run everything in your home, you need to do a bit of math.
  1. Generators are sized in watts, sometimes listed as kVA. 
  2. Watts are defined as volts x amps
  3. The vast majority of your household voltage is 120 volts. 
  4. Looking at your main breaker will give you the amperage rating of the electrical system in your house. 
  5. There will be a number stamped right on the device; that's the amperage rating. In my house, it happens to be 100 amps.
  6. Taking 120 volts x 100 amps, we get 12000 watts, or 12 kVA (kilo-volt-amps).  
  7. As with smaller generators, you don't want to exceed 80% of your rating for an extended time. So, to run my entire house, I need about 15,000 watts.
There are two common ways to get those watts, both with advantages and disadvantages:

Solar Panels
Solar power is fairly low-maintenance, and with very low operating costs once the system is in place. However, a solar array large enough to produce 15,000 watts isn't cheap, and requires a fairly large area for all the panels. In addition, while solar works great in Arizona or Florida, here in Utah, snow greatly reduces the output of solar panels when you need them the most.
  • Initial cost higher than generators
  • Requires more space. 
  • Does not work well during overcast days or in inclement weather. 
  • Initial costs may be able to be offset by utility or government subsidies
  • Has almost no ongoing maintenance requirements or costs.
  • Can sometimes be used to sell power back to utilities. 

Large Backup Generators 
Generators are another option. They cost less than solar to install, and are often less complicated. They have a compact footprint, able to fit into almost any yard. Properly maintained, they'll provide ready, consistent power... until the fuel runs out.

While gasoline is the fuel of choice for smaller generators, propane is popular for large gensets. It can be stored in far larger quantities, and requires no special consideration for long-term storage. It is also delivered by a vendor, so when you need a refill, all that is required is a telephone call. In rural areas, it is common to run entire houses on propane, so your home may already have half of what you need to install a genset.
  • Require fuel.
  • Require regular maintenance and upkeep.
  • Risk of fire or asphyxiation if improperly used. 
  • Lower initial cost.
  • Smaller footprint.
  • Provide power no matter the weather or season. 

While neither option is cheap, they are head and shoulders above any other alternative power source. The power source you choose will depend on your needs and situation, but if you're going to be bugging in for a long haul, you need to have something in place.


No comments:

Post a Comment

The Fine Print

This work is licensed under a Creative Commons Attribution- Noncommercial- No Derivative Works 3.0 License.

Creative Commons License

Erin Palette is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.