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Getting the right size generator is always a great confusion for buyers. And it is quite obvious as good generators are expensive and you want to buy a unit that meets the maximum of your work needs. While an outdoor generator that is best for your 1500 sq ft home might not be a good choice for recreation activity use. So it is important to focus on the size of the generator.

Power outage is the most common reason to buy a backup generator. While some regions experience a rare power cut, 1-2 a year, hurricane-hit areas experience frequent electricity cuts. And unfortunately, such power cuts can last for days and in the worst case, for weeks. So it is better to keep a good portable generator at home for such emergencies. But again the question arises, what size generator do I need to run my home?

What Size Generator Do I Need

Before we begin with an in-depth generator buyer guide, it is important to learn about the types of generators. This will help you decide the right model for your need better. Apart from the generator type, there are a lot of factors that help to determine the right size. And as you move ahead with the article, you’ll be able to decide the right generator size to buy.

Types of Generators

Before brainstorming about generator size, you must check what type of generator do you actually need. The model that is good for your RV might not be the best to power the whole house. Below listed are different types of generators.

Whole House Generator

Also known as a standby generator, this is an automatic backup electric system. These units are hardwired to your home and programmed to supply backup power within seconds after the main supply is off.

The automatic transfer switch of a home backup generator senses the power loss and starts the engine to keep the appliances of your home running until the main supply is back again. This uninterrupted supply of power and the ability to run multiple heavy-load appliances simultaneously makes them ideal for powering the whole house.

Inverter Generator

Inverters are best known for their quiet operation and better fuel efficiency. This is because an inverter generator is capable of producing DC(Direct current) power which the inverter ‘inverts’, i.e, convert it to AC back from the DC.

This inversion results in the formation of a pure sine wave which is similar to that you get in the main supply of your home. Such a clean supply of power ensures the long life of appliances as well as needs less fuel. This makes inverters best for RV or to charge/run battery-operated tools/devices.

Portable Generator

Temporary supply of power is best fulfilled by portable generators. These units use gasoline or propane to turn an onboard alternator that produces electricity. Many dual fuel portable generators support the use of both, gas and propane, making them ideal for outdoor use.

There are multiple power outlets on an outdoor portable generator. From running home air conditioners to charging sensitive electric devices, a reliable portable generator is good for home backup and outdoor activities like camping, tailgating, birthday party, and similar events.

Solar Generator

You do not need gasoline, propane, or fossil fuels to generate electricity with a solar generator. Thanks to its solar panels that convert DC power from sunlight and store it into a battery. When you need electricity, simply plug the appliance/electronics into the battery.

Solar generators are classified as portable power stations as they are easy to set up, require no fuel, and are lightweight. They are best for off-grid living, camping, or area that receives maximum sunlight.

What are Starting, Surge, and Running Watts?

Every appliance is rated for its voltage consumption. And voltage consumptions vary according to its watts. A high-watt appliance will definitely consume more power than a low-watt one. And watts matter when you are using a generator to power many appliances at once. So you’ll see many home/outdoor generators that will provide you with 2 pieces of information, surge, or starting watts, and running watts.

Starting watts, also known as peak or surge watt, is the amount of power it takes for an appliance to start. Starting watt is generally higher than running watts. They are mostly used by appliances that feature a motor such as a window air conditioner, sump pump, etc.

The other one is running watts that determine the energy required to run the appliance after the initial kick. An example will help you understand the difference between starting watt and running watt better.

Suppose you own a 10000 BTU air conditioner that requires 2200 starting watts. This surge wattage is to be maintained for the first few seconds before its energy demands fall low. Then, your AC will require a constant supply of 1500 watts, aka, running watts.

Now here, you need to choose the right size generator that meets the required power demand. Many units will meet the running watt requirement but fail to produce enough surge watts. Here, in this case, a portable inverter with 2200 surge watt and 1800-watt running watts is ideal to run a 10000 BTU AC.

When Do You Need The Generator?

While a rare power cut for a few hours is tolerable, the problem arises when you have to sit for hours without electricity. And needless to say, but electricity is a prime requirement in today’s world. The below points will help you understand do you really need a generator and if yes, what size generator is best for your home?

Frequent Power Outage

Not all of us a lucky enough to experience a constant supply of electricity. And if you live in a region with high chances of a hurricane hitting the city then a good backup generator is a must. The chances of power loss after a hurricane, storm and other natural calamities are extremely high. There is no electricity for days, or worse, weeks. And it is a good idea to keep a reliable home backup generator for rough days.

A standby home generator or a large inverter is ideal for frequent power outages. They supply power in Kilowatts and are capable to power more than one heavy-load appliance like a refrigerator, deep freezer, etc at a time. During storms or blizzards, a whole house generator will keep the heater and protect pipes from freezing.

Occasional Power Cuts

If hurricanes, blizzards, or ice storms do not hit your city often then it is pointless investing in an expensive standby home generator. A large portable generator or inverter is ideal for occasional power cuts that last for hours. These models are less expensive than standby generators. However, you need to install a transfer switch and also pull out the generators in time of need. But it’s all worth it if you see the larger picture.

Rare Power Outage

If you’re lucky to experience a power cut once or twice a year then a budget inverter might do the work. A good mid-size inverter runs quietly and provides enough power to run a window AC, space heater, fridge, fan, and other small electronics. The pure sine wave of inverters ensures stable output that prevents your expensive appliances from overload/underload damage.

Need in Emergency

Emergencies are uncalled for but you must remain prepared for tough situations. And inverters or mid-size outdoor generators are best for emergency use. They provide enough power to run essential appliances like a deep freezer, lights, and fan. This will prevent food spoilage plus you can charge essential electronics like phones, tablets, radio, etc to remain updated.

When Do You Need Extra Power From Generator

How Much Generator Power Do You Need?

The best way to determine how much generator power do you need to run home appliances or RV is by calculating the wattage. Check for the rated wattage of the appliances/electronics manually and calculate them. The below list will give you a rough idea about how much power does different appliances consume.

Heavy-Load Appliances

  • Air Conditioner(Window): 600-1500 watts
  • Air Conditioner(Central): 2000-4500 watts
  • Water Heater: 1200-3500 watts
  • Sump Pump: 800-2000 watts
  • Garage Door Opener: 750-1500 watts

Home Appliances

  • Countertop Microwave: 800-1800 watts
  • Refrigerator/Deep Freezer: 600-850 watts
  • Television: 150-300 watts
  • Vacuum Cleaner: 500-1400 watts
  • Coffee Maker: 600-1200 watts
  • Bread Toaster: 800-1500 watts
  • Hair Dryer: 900-1500 watts

Small Electronics

  • Mobile Phone: 2-6 watts
  • Laptop: 20-50 watts
  • Tablet: 10-15 watts
  • Bluetooth Speaker: 75-150 watts
[Note: This is a rough estimate. Again, I would say it is better to calculate the wattage of various appliances manually to pick the best generator size. Also, buy a generator with watts a bit more than calculated as appliances with a motor need surge power for a few seconds for a flawless start.]

The Bottom Line

Buying a new generator is a lot of work and I totally get it. It is because generators are expensive and you do want to see your hard-earned money go in vain. Now you know that there are various factors like usage, watts, surge power, etc, that help in selecting the right size of generator for home, RV, or outdoor use. And now you know exactly what field to focus on and what type of generator will best suit your requirements. Be prepared for emergencies and never sit in darkness for long hours with the best generator.


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