Generators use fuel sources like gasoline, natural gas, or solar energy to produce electricity, so that you can power a campsite, recharge mobile devices, or run essential appliances at home in the case of an emergency. They range from small portable generators that are ideal for camping to large standby generators that are essentially permanent fixtures outside the home. The first generator was invented back in 1831 by Michael Faraday. Technology has certainly evolved since Faraday joined a magnet, cotton and some wire—now there are many different types of generators, each with their own advantages, disadvantages, and optimal applications.
1. Portable Generators
Small, compact, and easy to carry or cart around, portable generators are typically fueled by gasoline, propane, or solar energy because these fuel sources are readily available. Gas and propane can both be sourced from a gas station, while solar energy comes directly from the sun. Their small size means that these generators are easily stored in a vehicle or kept in a shed or garage until they are needed.
On camping trips, a portable generator can recharge mobile devices, run the camp hot plate, or keep the lights on after the sun goes down. However, these generators sacrifice power production for mobility, so they aren’t able to produce the same amount of energy as larger standby generators. Their reduced size and capacity means that portable generators come at a more affordable price.
Best for: Camping, or to keep in the car for emergencies
Editors’ Choice: The Champion Power Equipment portable generator (available on Amazon) is a dual-fuel machine that runs on either gas or propane, and is equipped with a set of wheels for easy maneuverability.
2. Inverter Generators
Inverter generators can be whole-home generators or portable generators, but they differ in the way that they produce electricity. A standard generator produces electricity in a single-phase and can’t keep the flow of electricity steady. Inverter generators produce electricity in three phases, creating a high-frequency alternating current (AC), which is then inverted to a direct current (DC), and finally inverted once more to a stable AC output.
This process seems complex, but it actually helps create what’s known as clean energy, or energy that remains stable while in use. For this reason, it’s suitable for use in sensitive electronics, like phones and laptops. Due to the stable energy output, inverter generators also operate more quietly.
Best for: Protecting electronic equipment from power surges
Editors’ Choice: This WEN GN400i inverter generator (available on Amazon) provides clean energy and is free of voltage spikes, making it safe for use with laptops, phones, and other sensitive electronic devices.
3. Standby Generators
A standby generator’s high price tag puts it into an entirely different category than that of portable generators. While a small, portable product can be picked up, carried, or packed into a vehicle, a standby generator is a semi-permanent feature of the home—it actually takes up more space than a standard air-conditioning unit. These generators have a large fuel tank and a commercial-grade engine with high fuel efficiency, which allow them to provide power to the whole home in emergency situations.
Great for powering small cabins or backup emergency systems, standby generators are sometimes outfitted with WiFi connectivity that allows the user to monitor the generator’s status via a mobile app. Aside from cost, the main disadvantage of a standby generator is that they require regular maintenance to make sure that they are operational in case of a blackout.
Best for: Turning on automatically in response to a power outage, and providing a home with uninterrupted power
Editors’ Choice: The Generac 7043 standby generator (available at The Home Depot) features WiFi connectivity, and allows users to monitor the status of the generator from anywhere via the mobile app.
4. Gasoline Generators
Generators can run on a variety of different fuels, but the most common fuel for portable and inverter generators is gasoline. Any generator that operates on gasoline falls into this category, which makes broad observations about them difficult. The power, features, and suitable uses of a lightweight, portable generator that runs on gas and those of a gas-fueled, inverter generator are different.
Gas generators have relatively straightforward controls and low prices, which makes them good picks for inexperienced operators and shoppers on a limited budget. On the downside, this kind of generator has high emission rates, and runs on a fuel that is more expensive over the long run than propane, diesel, or natural gas.
Best for: Shoppers who are on a budget, or use their generators infrequently
Editors’ Choice: Fuel the campsite with this Westinghouse WGen7500 gasoline generator (available on Amazon), which runs for up to 11 hours on a 6.6-gallon tank of gasoline.
5. Diesel Generators
Diesel generators, as their name indicates, are fueled by diesel instead of gasoline. Most products in this category are standby generators, though there are some inverter and portable diesel generators out there. Generators that run on diesel can provide a more efficient power output than gasoline standby generators. There are cost benefits to buying a diesel generator too: Because diesel generators are more fuel efficient than gasoline-powered models, you’ll spend less on fuel over the long term.
These generators can work well in freezing temperatures if they are filled with winter diesel fuel. Regular diesel fuel can freeze and gel, preventing the generator from starting. Diesel’s low burning temperature puts less strain on an electric engine than gasoline or propane, allowing diesel generators to have a higher level of durability and long life. However, keep in mind that diesel generators produce harmful emissions that can be toxic if inhaled.
Best for: Those who are looking for long-lasting, easy to maintain generators; those who need a generator for industrial use or as a whole-house standby
Editors’ Choice: Run the campsite for up to 32 hours on a 12-gallon tank of diesel fuel with Generac’s XD5000E diesel generator (available from Generac).
RELATED: The Power Outage Survival Guide
6. Natural Gas Generators
Generators that run on natural gas tend to fall into the standby generator category, though there are some portable generators that also run on natural gas. Compared to diesel and gasoline generators, natural gas generators produce a significantly lower rate of emissions, making them a great choice for whole-home backup power.
Natural gas generators are very durable and can last for years with regular maintenance, though the initial cost of installing these systems is relatively high. Another downside to natural gas generators is that they can be vulnerable to extremely cold climates, so they may not be the best option for residents of Alaska or the northern states bordering Canada.
Best for: Eco-friendly shoppers who are concerned about pollutant emissions levels; whole-house standby generators
Editors’ Choice: The portable Sportsman 805420 generator (available at The Home Depot) runs on gasoline, propane, or natural gas and it can be used for a tailgate party, at the campsite, or as a backup for a home electrical system.
7. Solar Generators
Whole-home solar generators are very expensive to install, though the fuel is renewable and free. These generators are ideal for camping or keeping in the car as an emergency source of electricity.
Solar generators are typically made with built-in solar panels, but some come with detachable solar panels that can be set up or angled to better absorb the sun’s rays. The disadvantages of these generators is that they don’t work when it’s dark outside, and they don’t produce a whole lot of power.
Best for: Eco-conscious shoppers who can afford high upfront costs of whole-home solar generators; portable generator users who don’t need a lot of backup power
Editors’ Choice: The portable Jackery 1000 solar generator (available on Amazon) comes with two large solar panels that produce green electricity for charging tablets, phones, and other mobile devices.
RELATED: Solar Power Systems 101
8. Hydrogen Generators
Relatively new to the market, hydrogen generators are not easy to find. These machines are fueled by hydrogen gas and are designed with internal fuel cells to help manage the system’s fuel efficiency. Some of the advantages of purchasing a hydrogen generator are that they produce a higher power output than other generators, and they’re sturdy and pretty resistant to impact damage.
On the downside, because there are so few hydrogen generators on the market, they aren’t cheap—and it may take some searching to find a product that meets your particular needs. These devices are efficient and durable enough to make them worth seeking out, though, and we’ll hopefully see more and more companies producing hydrogen generators in the coming years.
Best for: Homes or businesses that require an uninterrupted power supply (for security or health applications, for example); remote areas; indoor use
Editors’ Choice: The H2Sys hydrogen generators (available from H2Sys) can be used as a backup generator for the home with an integrated hydrogen tank and fuel cell system for high efficiency.