How to Find the Best Generator for Your Needs

If you’re in the US and have lived through a power outage caused by a snowstorm, hurricane, or other weather event, now’s the time to consider getting a back-up generator. But which is the best generator to survive a blackout? 

We’ve previously written on both the best fuel-efficient portable generators, and the best solar-powered generators we could find too, but it’s helpful to know what size you need before taking the plunge and buying one.

First things first, though: ask yourself the following question. 

Do you even need a generator? 

In short, yes, you probably do need a generator. The need is arguably greater if you live somewhere relatively rural and might face prolonged power outages. But, even if you live in an urban area, you might do well to have a generator if the electrical grid is notoriously unreliable or vulnerable to outages. 

Most people living in America experience 1-5 blackouts every year. Some of these are short power outages lasting just a few minutes or up to an hour. These may even be planned as rolling blackouts to help the electrical grid meet power demands at peak times. In other cases, though, a blackout could last for days or even weeks.

Blackouts, as mentioned, may be planned by electricity companies, but many blackouts are the result of accidents, including people driving into electricity poles or animals causing damage to infrastructure. Storms, heavy snow, and other weather events can also cause power outages, and extreme weather is now more likely than ever before in your life, thanks to climate change. Depending on where you live, this might mean more wildfires, snowstorms, hurricanes, flooding, wind storms – all of which can cause disruptions to the energy grid.

Where I live, in a relatively rural place in the Pacific Northwest, my main worry in terms of power is a blackout caused by a major earthquake, windstorm, or snowstorm. A whole area of a nearby town experienced a power outage recently after a bird strike on power lines! And last winter, thousands of folks on a nearby island were without power for more than a week after heavy snow and winds, while I experienced a few hours-long power outages thanks to fallen trees and downed power lines.

Having recently moved from the city, away from the mainland, these outages really brought home the idea that I needed to be prepared for potentially days or weeks without power from the grid. That led me to add a portable solar panel to my earthquake preparedness kit. I’m also seriously considering buying a back-up generator, despite hoping I’ll never have to use it.

So, generators aren’t just for survivalists living off grid, nor for RVers, or other nomadic folks. But is now a good time to buy a generator?

Yes! Seriously. If you think you’ll need one in the next few years, now is the time to buy. The price of these things is only going to go up as demand increases and raw materials become scarcer. Also, the price of generators will likely increase in the last quarter of 2019, thanks to tariffs imposed by the Trump administration. Why? Because while many generators are made in the USA, the parts for those generators still typically come from China. Also, it’s worth noting that the price of generators spikes in December and January, meaning this summer is the best time to buy a generator.

The worst time to buy a generator? During a blackout. If you and hundreds of other people rush to the store when the power goes out, chances are slim that you’ll find a suitable generator for a good price. Plan ahead, save some money, and stay safe and warm at home during the next storm.

What kind of generator should you buy?

There are two main types of generator: portable and standby. Portable generators are best for use in an emergency and are great for anyone who wants to take a generator on the road, camping, or who might need to move it around a property. Standby generators are built-in, meaning they are permanent systems wired into your home. 

Standby generators – pros and cons

Standby generators can easily be switched on to compensate for a loss of power during a blackout. They just replace the electricity you’d usually draw from the grid. In general, a standby generator should be able to produce enough power to meet the normal demands of your home. They can also connect to an existing natural gas line in your home or can run on propane or diesel.

Standby generators automatically switch on during a power outage. If blackouts are common where you live, a standby generator is probably your best bet. This kind of generator is a great fit if you have concerns about food spoilage or other issues related to the power going out while you’re away from home, at work, school, or while on vacation.

The disadvantages of standby generators are their relative expense compared to a portable generator ($2,500-$5,000 vs. $200-$800 on average), and the requirement for professional installation and maintenance. 

Portable generators – pros and cons

Portable generators are typically much more user-friendly and, unsurprisingly, are portable. Most models come with wheels for convenience. They don’t require professional installation, are far less expensive (usually) than standby generators, and offer flexibility, making them a good fit for travelers and anyone who thinks they might move on a somewhat frequent basis.

As for disadvantages, portable generators can be loud! (So, you’ll want to figure out where to put yours to minimize noise disruption.) Portable generators are also usually less powerful, meeting the power needs of just a few select items rather than a whole house.

You will also have to manually refuel your portable generator as most can’t be hooked up to a natural gas line. This can also make them more expensive to run (Watt for Watt) compared to standby generators running off natural gas. 

You also need to factor in storing large amounts of propane or diesel/gasoline if you have a portable generator. If you don’t use and refuel the generator regularly, you might need to add fuel stabilizer to your gasoline. Propane is safer and easier to store than gasoline and burns more cleanly, but it is less efficient. However, diesel prices can fluctuate significantly, and diesel produces more air pollutants and is harder to store safely.

In short, if you’re adding a generator to your emergency kit, go portable. If you’re plagued by blackouts and want a one-time intervention that you then don’t have to think much about, go for a standby generator. I’ve reviewed the best portable generators here and the best standby generators to survive a blackout here.

UPS and portable power stations vs. generators

One other option I should mention is backup battery power. Known as an uninterruptible power supply or UPS, this type of power source doesn’t burn gas, meaning it can be installed inside your home to provide power if the electrical grid cuts out. 

A full home system typically costs between $15,000 and $30,000 and require professional installation, but they are far more environmentally friendly, and far less hazardous to health than a generator. The main downside, aside from the price, is that a UPS can only provide as much energy as the battery holds, meaning it may not be sufficient for an extended power outage.

You can also get what’s called a portable power station, which is basically a large capacity battery pack that you charge in advance for use during a power outage. You charge this via a regular electrical outlet or using a solar panel in some cases. 

One huge advantage of a portable power station is the noise, or lack thereof. These things are super quiet, making them ideal for apartments. And, given you don’t need to fill them up with propane or diesel, it’s also safe to run one of these in an apartment! These also present no risk of carbon monoxide poisoning and don’t need any cord pulling or such to start.

Downsides are, again, the cost. These ‘generators’, especially solar generators, are new to the market and cost a decent bit more than most portable gasoline generators (although the best one I’ve found is comparable in price to its nearest gasoline powered rival). Costs range from around $750 to $3,000 for a portable power station. I’ve reviewed the best portable power stations here, and this is what I’ve ultimately decided to go for as part of my emergency preparedness kit, coupled with a solar panel.

Other considerations when buying and installing a generator 

Now that’s out of the way, what else do you need to think about when buying a generator? The most obvious consideration is budget, followed by space and placement, and energy source. 

Portable generators should typically be located at least 15 feet away from any structure, on a dry, level surface, in a well-ventilated area. Some smaller generators have now been designed to be able to be closer to structures, but it’s essential to check before buying and installing any generator.

All generators should be kept dry, but not covered in such a way to prevent air flow. Generators create carbon monoxide, which is odorless and potentially fatal. They are also a potential electrocution hazard.

A well-ventilated shed, barn, garage or other outbuilding is usually ideal for most generators as it is sheltered, will allow air pollutants to dissipate, and can help keep the impact of noise to a minimum. Speaking of noise, some generators use advanced engine and muffler technology to keep noise to a minimum. Inverter generators and insulation can make a big difference to noise levels, turning an obnoxiously loud large generator into something you can barely hear from a few feet away.

If you have to refuel a generator, let it cool down fully first. This helps to prevent accidental fires. Also, keep your fuel in a safe place away from sources of ignition. As for hooking up your portable generator to appliances, only use extension cords designed to be heavy duty. Cords should use 12-gauge wire at least, with 10-gauge or thicker preferable. And don’t try to draw more wattage than the generator can handle.

If you opt for a standby generator and need to make any changes to home wiring or natural gas hook-ups, get a professional. Do it right, do it once.

Most higher-end generators have a push button battery-powered electrical starter. Some older and cheaper models have a pull cord to get the generator going. Anyone who has ever seen a horror movie will see the benefit of a button starter. Batteries can fail too, though, so make sure you pick a model with a backup pull cord.

As for maintenance, some generators need to be started up and run for a few minutes every six weeks or so to keep them in good working order. Others are fine to just sit there year after year without being run. Clearly, if you’re buying a generator in case of the ‘big one’, and hope to never need to use it, the need to run the thing every month or two is pretty inconvenient. However, if blackouts are common and you’d use your generator every few weeks anyway, this isn’t much of a downside.

A few other things to consider when buying a fuel-based generator include:

Low oil shut-off – some generators will automatically shut down if oil falls below a safe threshold, to help prevent damage to the machine. This has long been standard on standby generators and is increasingly a feature of portable generators.

Fuel gauge – this makes it super easy to see how much fuel remains, which is handy during a longer period without power.

CARB compliance / emissions testing – The California Air Resources Board (CARB) is an environmental protection organization that focuses on the emissions from small engines, such as those in generators. Machines that are CARB compliant meet more stringent air quality standards and tend to be more fuel efficient.

Inverter generators

Most generators now feature inverter technology, with just a handful of cheaper models lacking this innovation. Generators that use an inverter are more energy efficient, have lower maintenance costs, and tend to last longer than those without. Why? Because the technology allows the generator to reduce the revolutions per minute (RPM) when demands for electricity are lower. This means less wear and tear on the engine, as well as quieter operation and greater energy efficiency overall.

There’s also another major advantage to inverter generators, but to explain what this is you first need to know a bit about how an inverter works. 

Inverter generators use pulse width modulation (PWM) to produce a continuous stream of energy (i.e. a pure sine wave). If you upgraded your microwave oven recently, it’s likely your new model uses inverter technology to cook your food more evenly. In a generator, inverter technology helps to avoid the usual fluctuations in the AC sine wave that occur with changing power demands. This fluctuation is called harmonic distortion (HD) and can damage sensitive electronic equipment. 

So, if you plan on using your portable generator to power a computer, television, or other expensive electronic gear, you want to look for an inverter generator. Or, failing that, make sure you only use extension cords with surge protection and unplug any electronic devices to avoid damage when mains power is restored.

What size generator do you need?

The last big question to consider when buying a generator is the size of machine you’ll need. This will differ for standby and portable generators and depending on your personal circumstances and needs.

Standby generator sizing

To work out the minimum wattage for your standby generator, calculate the total running Watts and add the highest additional starting Watts you’ll need to draw to power all your chosen appliances at the same time. This will help prevent the generator being overworked by a bunch of appliances all trying to start up at the same time, when energy demands are highest.

Most appliances will list the Wattage on their electrical cord or on the item itself, or you can usually find this online or in your user manual. As a guide, here are some common power requirements for household appliances:

• Sump pump: 750-1,500 W
• Portable room heater: 1,500 W
• Window air conditioner: 1,000 W 
• Refrigerator and freezer: 600 W
• Lights: 60-600 W
• Computer: 60-300 W (laptop or desktop)

If you’re getting a generator for emergency purposes only, consider only powering essential items such as heating, cooking, and communications equipment. If your generator is intended to power everything in your home, you’ll want to do a full inventory and add in things like your television, blender, slow cooker, refrigerator, computer, kettle, and so on. 

In general, if you have a 1-2 bedroom, 1 bathroom home with a 3-Ton air conditioning system, a 10,000 Watt (10 kW) generator should have you covered. For a 3-4 bedroom home, a 15 kW generator may be preferable. And, if you have a larger home with more than 5 bedrooms and a 5-Ton AC, consider getting a 20 kW generator. If you don’t have to factor in AC, you can easily get away with a much smaller generator, with a 7,000-10,000 W generator meeting the needs of even a larger house. You might also consider getting a 7,000 W generator for most of your home’s needs, and using a separate, smaller generator to power the A/C or heating as needed.

Ideally, while doing these calculations, you’d also look at ways to use less energy overall. This would allow you to save on your electricity bill and save money by buying a smaller generator, not to mention the environmental benefits of using less carbon-based fuel during blackouts. Indeed, there’s a certain painful irony in that the effects of climate change, i.e. blackouts, are leading more people to rely on gas-guzzling generators which themselves contribute to climate change.

Portable generator sizing

If you’re looking to get a portable generator to see you through the occasional blackout, you won’t need anything like the 20 kW capacity of a large standby generator. Instead, a small generator providing 3-4 kW can easily power a medium-sized refrigerator, TV, some lighting, a computer, and a few other appliances. 

Even if you want to run a window air conditioner, freezer, and other appliances, a 5-6 kW portable generator will have you covered. One of my top picks for a generator, the Honda EU7000iS, provides 7 kW of energy which will easily handle most medium to large homes, assuming you don’t run central AC.

Summary

Now that you’ve got a better sense of the size of generator you’ll need, consider exactly what you’ll be plugging into it. Some small generators only have 12 Volt plugs, while others can power 240 V appliances. Make sure you pick a generator you can plug everything into that you need. Also, if you plan on using a transfer switch to plug your generator into your home wiring system, make sure the generator has a four-slotted plug supplying 120 V and 240 V. 

A transfer switch needs to be installed by a professional. This switch is an addition to your home’s main service panel that allows you to hook up your generator directly. The transfer switch then let’s your generator power only the items connected to the designated circuit, without the need to hook up each appliance individually using extension cords.