Best 15000-Watt Portable Generator Review 2021 – [Our Top Selection]

Hurricanes, storms, vehicle accidents, and several other weather factors can cause interruptions in your electricity supply. But power outages due to these natural disasters and other issues shouldn’t bring your construction works to a painful halt.

Fortunately, there are larger generators on the market, producing up to 15000 watts of power, which can come handy to help construction crews and other people that live off the grid for one reason or the other.

This power is more than enough to run multiple large equipment and appliances, recreational vehicles (RVs), large tools, and others. In each of the generators reviewed below, you’ll find a wide array of outlets & features for ensuring you get the best generator power for your needs.

These sets are also cool for homes with lots of appliance and heavy power demands. And since our aim is to simplify the buying process for you as much as possible and help you choose the best 15000-watt portable generator that you can invest in, we’ve included a buying guide in this review to direct you to your best set.

Top 15000 Watt Portable Generators in 2021 – Our Picks


Generac 5734 GP15000E

15000 watt generators

US-based generator manufacturer, Generac, is a famous brand well-known for releasing some of the largest standby generators for years. If you’ve been searching for a portable generator, there are good chances you’d have come across their name since the company produces a slew of generators with different sizes to fit the specific needs of customers.

Occupying the top spot in this review article is the Generac 5734 generator. It’s a 15kW generator, which supplies you with the power you need.

Generator’s power

This model will put out 15,000 running watts & whopping 22,500 starting watts, delivering unbeatable power in its class. With this high starting watt capacity, the set can power larger tools and appliances.

In addition to this, the 992cc Generac engine was specifically built for generators, featuring pressurized lubrication mechanism for sending oil directly to key parts of the engine. The model comes with an electric start to make using the generator a lot easier.


The Generac GP15000E generator boasts one of the widest outlet selections of all the generator models in this article, making it a versatile option that allows you to use up the 15kW running watts. Checking the control panel, you’ll see the outlets are perfectly laid out in a bid to make sure you don’t face any issues hooking up just about anything to the set.

You can choose from two 120V 20A 5-20R GFCI outlets, two 120V 20A 5-20R outlets, one 125/250V 30A l14-30R twist-lock outlet, two 120V L5-30R 30A twist lock outlets, one 125/250V 14-50R outlet as well as one 12VDC 10A outlet. This array is among the best selections we‘ve come across in a generator, a testament to the very impressive offerings this Generac brings.

Runtime and fuel capacity

The GP15000E gets a large 16-gallon fuel tank, which allows for up to 10hrs of runtime at 50 per cent load, and there are an inbuilt tank fuel gauge and fuel filter to ensure easy maintenance.

Key features

The generator is all about business and doesn’t have a lot of outstanding features. It comes with electric start, wheels & a handle built into the frame, making the unit a lot easier to use.


The Generac GP15000E will most likely be the best choice for you if you’re planning to use high-wattage tools or appliances, where starting watts are essential. The average homeowner may not really require starting watts of 22000W for the majority of back-up power supplies. But if you’re making use of the generator to live off the grid, this model could be an excellent option to get.



Duromax XP15000E

One of the biggest names in the generator industry, Duromax makes an appearance on this list with the XP15000E. The manufacturer is known for building some of the most durable and reliable generator sets, which are used commercially & residentially. So, the XP15000E is a great option when it comes to a high-powered generator, usable both at home and on the job (construction) site.

Generator’s power

The Duromax model‘s 713cc V-twin engine puts out 15,000 starting watts & 12,000 running watts. The engine supplies 23HP (horsepower), with an operating volume of 74dba, and that’s pretty standard for a good number of generators.

It’s built to cater to heavy loads from construction or residential refrigerators, lights, home air conditioning units, in addition to power tools that have high amperage ratings. Considering this, you need not hesitate to rely on the XP15000E for your home backup power, along with complete RV electrical reliance, or for powering your whole job site.


In the outlet selection on the Duromax XP15000E, we’ve got a lot of options to use the full 12,000 running watts. Though covered outlets would be a cool option to see, the number of outlets on the unit compensates for this small drawback.

On the model, you can pick from one 120V 30A twist-lock outlet, one 120/240V 30A twist-lock outlet, four 120V 20A GFCI outlets, and one 120/240V 50A heavy-duty outlet for RV use. Since there are so many various outlets to select from, you won’t face any issues about plugging up just about any equipment or appliance to the generator.

Runtime and fuel capacity

It comes with a 10.8-gallon fuel tank, allowing for up to 8.83hrs of use at 50 per cent load. And this is an excellent runtime because it’ll enable you to enjoy a full day’s worth of power from this unit without the need to worry about refilling it.

Key features

This generator doesn’t offer any extraordinary key features, but it does give you the benefits of surge arrest & a digital multimeter, enabling you to monitor the vitals of your generator. Just like the majority of larger-sized generators, the XP15000E is equipped with wheels and collapsible handles. These aid easy transportation.


When you’re seeking a quality generator producing 15kW to power your large tools and appliances, you can’t go wrong with the Duromax XP15000E. It offers just about everything you need in a generator, designed to get the job done without you having to contend with any issues.


A-iPower SUA15000EC SUA15000E

A-iPower, which is among the lesser-known makers in this write-up, has been building a solid name for itself on the generator market. Let’s introduce you to the A-iPower SUA15000EC SUA15000E!

Generator’s power

The portable generator is powered by a 680cc OHV twin-cylinder engine with 24HP, allowing it to put out 15,000 starting watts & 12,000 running watts. So, the unit is a strong candidate for the best 15000-watt portable generator. It’s built to run several household equipment and appliances at once, which makes it a perfect option for your home back-up power.


When you take a first glance at the generator, you’ll be quite impressed to find covered outlets since this is an option you might be expecting to see on some of the higher-end models. However, finding it on the SUA15000E shows they’re in tune with the features in vogue on the generator market.

Checking under the hard plastic, you’ll see 5 outlets in outlet protectors. These outlets let you plug in multiple equipment or appliances.

There are one 120V 30A l5-30R outlet, two GFCI 120V 20A 5-20R outlets, one 120/240V 50A L14-50R outlet, and one 120V/240V 30A l14-30R outlet.

Runtime and fuel capacity

It packs an 8-gallon fuel tank, which enables you to get up to 7hrs of runtime at 50 per cent load and 5hrs of runtime at 100 per cent load.

Key features

What’s the major standout feature on this machine? That’ll be the outlet protectors that help in blocking out dirt, moisture, and debris from destroying the unit. Also, there’s a four-wheel system to help you move the generator easily.

But the wheels are rather light-duty. For this reason, moving it through a job site could need some lifting. In addition to those features, the generator also features electric start. This is always a plus.


The A-iPower SUA15000EC SUA15000E offers great outlet selection and a number of quality features. This generator’s wheels limit the mobility a lot, particularly in grass & dirt. It’ll be cool for people that intend to keep it strapped down somewhere or move it on a flat and solid surface. However, for users that require to move it around on softer terrain, they could opt for another option on this list of the 7 best 15000-watt portable generators.


CAT RP12000E

Short for Caterpillar, CAT is among the top makers of heavy machinery worldwide and is also among the biggest brands in the world. For these reasons, you can expect nothing but the best from their lineup of 15kW portable generators, such as the CAT RP12000E, currently under review.

Generator’s power

It features a CAT 670CC v-twin OHV engine with an inbuilt idle mode option & a pressurized oil system, which makes sure the engine lasts for years to come and works as efficiently as feasible.

The generator supplies 15,000 starting watts & 12,000 running watts. This is ideal for complete home back-up power solutions or for use on a job site to power all your tools and lights.


The maker has done an excellent job in understanding ways the generator will be used by integrating protective outlet covers to ensure the outlets are protected always from things like debris, dirt, and moisture.

This unit has four 20A household outlets, one 12V DC outlet, one 30A 120/240V L14-30 outlet, two 30A 120V L5-30 outlets, and one 50A 120/240V L4-50 outlet. With these outlet selections, you can plug in just about anything into the generator.

Runtime and fuel capacity

It comes with a 13.2-gallon fuel tank that allows for 11.7hrs of runtime at 50 per cent load. So, it’s great for full day use on your job site or for overnight use when the issue of power outage crops up.

Key Features

The RP12000E features cool standout features, including LED control panel lighting that aids nighttime viewing, covered outlets, and inbuilt never-flat wheels that have a collapsible handle.


The CAT RP12000E has a competitive price point and is a great deal for you. As it’s designed primarily for commercial use, the average homeowner might need to find a high-powered generator set that’s made for the toughest conditions with the same price tag as a standard, non-commercially designed unit. We’d recommend investing in any kind of products from CAT, particular this generator model.


Champion 100111

Champion is yet another big brand in the generator industry, which features on this list with its 100111 generator. The company has built a solid reputation for itself as a leader in the industry for years, producing several different sizes of generators, which handle many different needs of customers.

Generator’s power

This generator draws power from the powerful 717cc V-twin Champion engine, which includes a battery-powered electric start, which can be switched on with just a simple push of a toggle switch. It delivers 12,000 running watts & 15,000 starting watts, ideal for use both commercially and residentially.


This manufacturer is reputed for doing an excellent job of pairing up their outlet selection using the power levels on their generator sets. Typically, you’ll get generators that offer large amounts of wattage capacities and poor outlet selections.

The 100111 further shows Champion is closely following the current market trends as regards which outlets consumers are looking for in their generators.

The Champion 100111 features different outlets, all of which come protected with plastic, snap-in protective covers that are a great addition, particularly on dusty job sites.

The outlet protectors cover a 120/240V 30A locking outlet, a 120/240V 50A outlet, a 120V 30A locking outlet, and four 120V 20A GFCI outlets.

Runtime and fuel capacity

What you get in this unit is around 10hrs runtime from the 5.9-gallon fuel tank, which should help last throughout a day on a single fill-up.

Key features

The most standout features of this Champion generator are the protected outlets, foldable handles, electric start, inbuilt wheels, in addition to a volt guard for protecting appliances from power surges.


Champion generators will always be among the best models you can get for use both residentially and commercially. The units are built tough to work smoothly on construction sites and also ideal for home use. The Champion 100111 is no doubt one of the best 15000-watt portable generators out there.


Dayton 6FYA4

Dayton is also another lesser-known brand, making an entry in this review article with the 6FYAA4. It’s the most expensive generator on this ranking. But does the huge price tag match its power and features? Let’s find out!

Generator’s power

The model is equipped with a 688CC Honda engine, including electric start. The engine puts out 20HP, allowing for 12,000 running watts & 19,600 starting watts. From all indications, this generator was designed for commercial use, especially because the full tube cage & bare-bones control panel aren’t really the coolest things to behold from a residential use viewpoint.


The Dayton 6FYA4’s outlet selection is quite standard for its class, but there are no protective covers, and that’s slightly disappointing if the generator is meant for commercial use. This generator gets one L5-30R 120VAC Locking outlet, two 5-20R 120VAC Duplex GFCI outlets, one 14-50R 120/240VAC outlet, and one L14-30R 120/240VAC Locking outlet.

Runtime and fuel capacity

The machine has a large 13.2-gallon fuel tank, allowing for an 8-hr runtime at 100% load, one of the best full load runtimes on this list. Hence, you can expect a full day use at full load. And that’s quite impressive.

Key Features

The generator has no features that can really be considered outstanding. With the price tag it carries, one would expect more features to be added.


This unit is a good example of a bare-bones generator. Starting at over $6,000, this unit could be regarded as a generator reserved for buyers in the commercial industry that have larger budgets. It’s not the best option for residential use since we’ve other budget-friendly generators with more features.


Northstar 15000

The Northstar 15000 is also one of the best 15000-watt portable generators. With its price in the higher range, let’s see how it’ll compare with some of the other options above.

Generator’s power

The portable generator provides 15,000 starting watts & 13,500 running watts via its Honda GX690 OHV engine, delivering 22HP. The running watts are slightly higher compared with the majority of generators on this ranking, making it perfect for users in need of a bit extra wattage throughout the runtime.

With the Honda engine, you can have peace of mind that you’re using a dependable machine since Honda is famed for its superb engines.


As regards outlet selection, this generator really beats the competition as it features 11 outlets for you to pick from. Though they’re not covered with protective outlets, the offerings are still impressive.

The unit has a control panel, packed with eight 120V household outlets, one 120/240V 50A outlet, one 120V twist lock, and one 120/240V twist lock. The eight household outlets are quite unique, allowing you to plug in up to 8 various small appliances to be run at the same time.

Runtime and fuel capacity

The Northstar 15000 packs an 11-gallon fuel tank, allowing for eight hours of runtime at 50 per cent load. This is slightly less efficient compared with most of the generators above. However, it still offers a full workday’s worth of dependable power.

Key features

Here are some of the cool features to expect on this generator: premium 100$ copper-wound generator head, an ultra-quiet muffler, vibration isolation mounts, in addition to a variable timing digital CDI ignition.


This model is sold at nearly $1,000 more than several of the other similar generators. But we’re not really sold on the additional cost. While the outlet selection and a 4-year warranty are a great upsell, for this amount of money, we’d have expected a bit more features to make the extra cost justifiable.


15000 Watt Generator Buyer’s Guide

Having gone through the 7 best 15000-watt portable generators, you’re now a step closer to getting your perfect option. As earlier promised, in this section, we take a look at a comprehensive buyer’s guide to help you find the best generator to buy.

Type of Generator

First note that 15000kW generators can either be portable or a standby unit, and the major difference is that portable generators can be transported easily as nearly all of them feature wheels and handles.

On the other hand, a standby generator is a one-spot-installation machine, which, once installed, cannot be moved unless you’re relocating it. Furthermore, standby generators are generally extremely powerful and highly responsive. Also, they’re automatic so there’s no need for you to start the generator. But they’re quite costly.

Dual-fuel and single-fuel generator is another category. A dual-fuel generator will offer you the freedom for choosing between the fuels it’s compatible with, either gasoline or propane, propane, or natural gas. But as a result of this addition, the generator is much pricier in comparison with a single-fuel unit.

Noise level

Of course, if you want a backup generator for your home, then you’ll need to be ready to cope with some noise. For this reason, you need to ensure the 15kW generator you opt for runs quietly. These generators come with different noise levels, so you need to take this into account. Since job sites are often noisy with various tools making high decibels, it’s best you go for an ultra-quiet model.

Power output

Why do you need a 15kW generator, and how long do you want it to work? Those are the first questions to consider before you buy the best 15000-watt portable generator. If you require the generator to keep your laptop, PC, mobile phone, Wi-Fi running, then a 15000-watt generator is okay for you.

But if you’ll be running multiple large appliances, such as microwave and electric oven at the same time, then you’ve to check to see if 15kW power will be enough. Consider adding all the wattage of these appliances to determine the value of required wattage. And bear in mind that starting power is nearly double the running power.


What are the generator parts made of, and are the materials durable? You’ve to make sure the generator you choose to buy is designed using high-quality materials, which can resist corrosion and rust and also give the best durability. Make sure the whole construction is something reliable & robust, having a strong protective frame.

Ease of transportation

Most of the best 15000-watt generators are portable. If you require a generator you can make use of in a lot of different locations for various applications, then consider going for a portable option: A generator featuring wheels & handles.

Frequently Asked Questions

Here are some FAQs to help shed light on any grey areas you may have about your best 15000-watt portable generator:

Is there any need to exercise my generator?

Yes, you need to do so. It’s simple required maintenance. Generators need things like scheduled filter and oil changes for making sure that you realize the optimum performance as well as years of reliable service. Consider checking the user’s manual always for information about routine maintenance procedures. Also, you’ll see some portable models, which are designed with inbuilt maintenance reminders on their control panel.

How does the working principle of a generator fuel valve look like?

A generator fuel valve is a small device, set to allow or stop fuel from getting to the engine. Consider to always keep the fuel valve open before you put on your generator and close it directly after switching the generator off.

In a Nutshell

Hurricanes, storms, vehicle accidents, and similar other weather factors can cause power outages. But these outages as a result of natural disasters and other issues shouldn’t disrupt your construction works.

Luckily, we’ve larger generators that put out up to 15000 watts of power that can be quite beneficial for construction crews and other persons living off the grid for one reason or the other.

Here are the 7 best 15000 Watt Portable Generators to help you handle any power outage or blackout situation whether commercially or residentially:

  • Generac 5734 GP15000E
  • Duromax XP15000E
  • A-iPower SUA15000EC SUA15000E
  • CAT RP12000E
  • Champion 100111
  • Dayton 6FYA4
  • Northstar 15000

The power from these machines is more than enough to keep multiple large equipment and appliances, recreational vehicles (RVs), large tools, running at the same time. The sets are also ideal for homes that have lots of appliance and heavy power demands.

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