Estimating Your Off-Grid Power Needs, by Mrs. Alaska

The European energy lobbying group 2000WATTS.org proposes that 2,000 watts is the amount of power that would be available to humans if each one of the 7.9 billion people on the planet had access to the same amount. Their concern is that our power resources are dwindling.

Whether you agree or disagree with their assumptions, it is interesting to consider how much power our frequently used appliances require.  When I lived in a city, I never thought about this.  I just flipped switches and paid utility bills.  However, with so many parts of the country suffering power outages, I imagine that more people are now wondering, “If the power goes out, what do I do?”  What could I run with a generator of this or that size?  How much fuel would that require?”

Here in remote Alaska, we built our own power supply so we are alert to power hogs and power sippers that we decided to buy or do without.  And since the generator we use as a backup to our solar panels and wind turbine is a Honda 2000 (producing 2,000 watts), we know how much our various appliances and tools require and which ones we can or cannot use simultaneously without tripping a circuit breaker.

A fabulous resource for prudent people adding up their power usage in order to determine an appropriately sized backup generator is Generatorist.  It identifies the power draw of appliances ranging from full house A/C units to a night light, as well as commercial equipment and RV gizmos.  It also lists products you can buy to measure the current draw of each appliance in your home.  We have one, called a Kill A Watt.

Additionally, homeowners will find that many, but not all, machines list their amp, volt, and watt requirements in a plaque on the back or bottom.

FOR OUR HOUSEHOLD

The power hogs in any home are appliances that create heat and move water.

Therefore, at our off-grid home, we do not have any of the following electric appliances:

  • Oven:  2,150 watts
  • Stove: 2,100 watts
  • Dishwasher:    1,500 watts
  • Clothes dryer:  5,400 watts !!!
  • Hair dryer:       1,250 watts
  • Home heater: (highly variable, with furnace and fans or radiators, other)
  • Air Conditoner:  (highly variable, by BTU size, and window or central).

See Generatorist for more examples.

Instead, I hand wash dishes, line dry laundry (I love that fresh scent),  cook on a propane stove/oven with a manual pilot light ignition, heat the main cabin with wood and warm the guest cabin with a propane heater.  We open and close windows and curtains to impact interior temperatures.  And we have an outhouse, not a flushing toilet, so no power draw there.

We also lack many gizmos that I think are rather unnecessary, like electric can openers, bread makers, and televisions.

A few high-wattage power tools are important here because we have found no convenient alternative. Most of these function for short duration, and we ensure that we are not maxxing out our power with other demands at the same time. Otherwise, the circuit breaker turns off all power as a safety precaution.

For example, we occasionally use the following useful electric tools:

  • Circular saw:  1,400 watts
  • Disk sander:   1,250 watts
  • Shop vacuum: 1,100 watts

A very important power tool we use frequently is a 5-ton log splitter, which draws 1,500 watts.  Bryan turns on the generator almost every time he uses this, which is an hour per day ($1/hour of gasoline) about 4 days per week in summer.  This $16 of gasoline saves his shoulders from hand-splitting 11 cords of dry wood to warm our home and heat our hot tub during our long, Alaskan winters.

For the kitchen, I bought my first new appliance in over a decade: a small air fryer.  I love it, but it draws 1,700 watts!  So I make favorites like salmon egg rolls or fried chicken as an occasional treat.  Note that this appliance replaces the need to fly out cans of Crisco for deep frying (at a $.50/lb transportation cost) and then figuring out what to do with the leftover oil. My husband bought a microwave oven as a backup in case our propane oven suddenly died.  I hardly ever use it, but others may routinely use theirs.  This small one draws 1,050 watts.  The powerful meat grinder that we use when we process bear and rabbit meat draws 575 watts.  Other appliances: a blender/food processor (450 watts) and a coffee/spice grinder:  (150 watts).  Many kitchen tasks I do by hand with a mortar and pestle, a nut crusher, a food mill, and kneading bread dough.

Moving water from our well to the house, washing machine, and yard hoses requires 1,500 watts.  So we tend to time water projects for sunny or windy days, or when the generator is on.  Our on-demand water heaters for the sink and shower are powered by propane, with electric ignition.

FOR OTHER HOUSEHOLDS

For a household to figure out how powerful a generator is needed to power its priorities, it is important to know that  “running time” wattages can be magnitudes lower than “surge” or “start-up” requirements.  Some of the following might be priorities for a house impacted by a power outage in a hot climate, thus requiring a powerful generator:

Appliance                                   Running wattage             Surge/start-up wattage

  • Chest freezer                         500                                   1500
  • Central A/C (24,000 BTU)     3,800                                11,400 (!!!!)
  • Electric water heater             4,000
  • Ceiling fan                             60
  • Garage door opener              875                                    2,350

I have not added up all of our routine power uses but they are modest:  two laptop computers, a cell phone, and the freezers in summer.  Is it at or under 2,000 watts?

I think it may be, except when we use the washing machine.  One day we water the gardens for several hours (1,500 watts).  Another day, we briefly cut (3 minutes) and sand (10 minutes) wood (to replace planks in steps or the dock. (1,250 watts and 1,400 watts each).  A third day I cook egg rolls in the air fryer for 8 minutes.  On a sunny or windy day, with little else on,  I run a high-value load of wash (1,250 watts, but with a high surge + moving water from the pump).

Within these parameters, we live a low-cost, low-power life in a lovely setting with low pollution, low stress, gourmet meals, and the satisfaction of tasks well done.

Who needs an electric can opener?