There are many reasons to get a generator for your home or camping and there are a large variety of types so it can get a bit confusing when you’re trying to make your purchase.
The first thing is what is your need.Your need can be found by adding up the power requirements of all of the things that you need to run simultaneously and then matching that to the normal running output of the generator. You will often see generators rated at a Surge and Normal rating such as 4000 surge / 3500 run. For practical purposes you don’t consider the surge rating for anything other than its ability to output a few seconds of extra power that can be used to jump start large electric motors in your refrigerator, hvac and AC units. The regular run time is what is needed for continued running of those devices. You should also make allowances that generator run times are normally at 50% capacity meaning not running at maximum power at all times. If the appliances you need to run require 3500 watts you might be better off choosing a generator that is in the 5,000 to 7,500 range rather than one that is rated at 4,000 watts because you are going to put less stress on your engine overtime. Remember though the larger the engine the more fuel it will use. So the first thing you need to do is add up all your power needs and decide which you can live without or which you can alternate and then decide on the size generator you need.
Standby Generators To Power Your Entire Home
Need is different than want and you have to keep that in mind. You may want to completely power your home as you normally have it but only a very large standby generator that has a large supply of natural gas or propane is going to be up to doing this. If you are in an area that has utility shutdown you could find that your natural gas is also effected. This normally does not happen but it has happened even in large cities like Philadelphia during the winter where no or limited gas is available. If you live remotely or have a large propane tank then this is an option but standby generators do use a lot of propane.
Standby Generators normally require a professional to install them. Companies that sell these generators may have installers that can perform the electrical hookup to your circuit breaker that cuts your home off from the grid when the generator is operating or you might need to hire an electrician to make the connection. Your Electric Company will probably want to be notified and they might have special requirements and inspections. Your building official might require a permit and inspection.
Second option is a very large portable generator.
They come in the 7500watt and up range. They are expensive and most only run on gasoline. This means you will need to have a large supply of gasoline to feed your generator. For an extended period of days that might be a couple hundred of gallons you will need to store. Diesel Generators are harder to come by but military surplus is an option.
Normally even a large portable generator won’t be able to meet your entire home’s needs and you will have to select which circuits in your home are the most important. This will probably be your HVAC System, Water Heater, General Lighting and maybe a stove. This will depend on the size of your generator and what it can safely support without overload.
Third is Medium Sized Portable Generators
Medium Sized Generators would be in the 3500 to 7500 watt range and can do things like power a single refrigerator, general lighting and a furnace. You might also be able to power a window AC unit and some other items in your home. This is not to say that you will be able to run all of these things at the same time and it is very likely that you will only have a few things that are very important running in an emergency situation. Most Gas Furnaces can run off of a 3500 watt generator but that would most likely mean nothing else in the home will be running. In the middle of winter that is the most important thing. So with a medium sized generator you are making many more choices.
Fourth and Finally are Small Portable Generators
A small portable generator is great for camping or a remote cabin. They are also the choice of contractors that build new homes when the site does not have electric yet. They are sized between 1000 and 3500 watts and can power a variety of tools and small appliances. They are good for powering a Television or Computer for a few hours however you should run them through a UPS Power supply that will produce pure sinewave electricity. Power that is generated by any generator is dirty square wave power and can hurt electronics.
An option with small generators is to get an Inverter Generator that uses much less horse power to generate the electricity because the generator uses high power magnets and other technology. Because a smaller engine is being used the noise will be reduced substantially. Additional engineering goes into the engine’s housing and muffler but the muffler is not the primary reason this type of generator is so much more quiet. The difference between a Inverter and Standard Generator might be the difference of being able to stand right next to the inverter generator and have a conversation vs having to walk 15 feet or more from a standard generator. It is the same as with your lawn mower.
Final Note
Although these four types do not describe all of the options out there they do cover the major points that are necessary to understand when buying a Generator.
The first thing you need to know is the need that you have. Standby Generators and even large portable generators can not run indefinitely and are only rated to run for about 12hours at a time. What fuel source do you have? Will you be using natural gas or propane? All of the generators above can be purchased to run off propane. There are dual fuel options out there and there are diesel options out there if that is the best fuel source for your situation.
The main thing in your selection is that for the best price / performance you need to match your need to your generator and then stay within what is normally available on the market. This might mean that you have to change your needs and understand that an emergency backup generator is not the same as a power company’s generator.
If you live remotely and you will need off grid power for an extended time then you should look into alternative energy options like Solar, Wind and even small streams can be outfitted for hydro.
If you are doing this you will also want to look into energy saving options and alternatives. Such as heating your home with wood, powering your appliances like your Stove, Water Heater, Refrigerator with propane and finding other ways to reduce your consumption of electricity.