Whether you are planing for a winter ice storm or summer hurricane there are a number of considerations that you need to take into account when planing your backup electric power supply.
The first thing you will need to do is size the generator necessary to provide electric for your primary services. You will want to decide which items in your home are a necessity and will allow you to stay in your home if it is undamaged by the storm or other event.
In the winter months you will need to have heat so power for your furnace is a necessity. If you have electric baseboard heaters you may want to use portable kerosene heaters during the emergency as the load on your generator will be high for this type of heating service.
In the summer months air conditioning may be a necessity depending on the health of the people in your home and your ability to be evacuated to proper care facilities.
Water will also be a necessity and if your local water treatment plant is out of operation then you will need to power a well pump to provide your own water.
Lighting is not a heavy user of electricity as long as you are not lighting up your whole house.
Computers if you are in a business may also be necessary as would be other appliances. It is not normal to power an electric stove, oven or other devices that can use a lot of electric.
Once you have compiled a list of the necessary items that need to be powered during a blackout you can calculate the load necessary to run them. Some items may require 240 voltage while most will run off of 110 volts.
Watts divided by volts gives your amperage. Amperage can be thought of as horse power available in either 110 or 220 volts. Each device will have its own wattage rating … for instance a common house hold light bulb uses 100 watts of 110 volts and will require .9 amps of electricity.
If your generator was able to put out 20 amps at 110 volts then you could run 22 light bulbs.
Fuel Type Considerations
If items in your home run off of Natural Gas or Propane then you can add these fuel sources to your choices of fuel types available for your generator. If you do not have access to a dependable supply of natural gas or a propane storage tank then adding them for electric backup will probably be cost prohibitive.
The main difference between using natural gas and propane for electric generation is that Natural Gas is provided through street lines and propane is stored in a tank on your property. Although the supply of Natural Gas to your home will likely be available in most situations your utility may be ordered to shut down service. On the other hand storing a large propane tank in your yard can be dangerous. Special considerations must be made if you are in an area prone to flooding to anchor the tank and if you are in an area prone to tornadoes the same will be true.
Availability of gasoline and diesel fuels during an event will also be limited.
If electricity is not available in your area then it will not be available at your service station to run the pumps. You will need to travel a distance outside of the power failure area to purchase fuel or store fuel on your site. Although it is not the most difficult thing to store gasoline or diesel on site it can be dangerous to store large amounts of it to power your home for long periods of time.
Local codes will most likely prohibit you from storing fuel in the ground as a service station can for added safety so you will need to store your fuel in an out building or shed.
Another consideration is the fact that your vehicle will hold approximately 10 gallons of fuel so if you have a truck that runs on diesel or a second car you will have access to safe storage and transportation of fuel without the need for tanks or a large number of small containers. You will however need to reserve fuel for your vehicle to allow you to get to the service station to purchase more.
Duty Cycle or Run Time
Gasoline Generators will likely have the shortest duty cycle because they are not designed to run continuously. They also have a relatively small storage tank for fuel. Some larger models may be available with overhead valves and cooling systems but usually are not suggested for running longer then 8 to 12 hours at a time.
Diesel Generators can be run longer then the average gasoline generator however this will depend on the size and cooling system available. Diesel will also run longer because it is more efficient and some systems are designed to run continuously for days.
Natural Gas and Propane Generators are often designed for long run times and as long as you have fuel supply they can run for an extended period.
It is important to note that on site power generation of any type is not normally considered to be a permanent resource.
Another option is Solar Power and Wind. These sources of electric generation are not considered to be useful for emergency power generation but if they are installed on your home they can provide most of your power needs.