How to Choose a Portable Solar Generator

Solar generators have both advantages and disadvantages that we list, so you can determine if a solar generator is right for you.

Advantages of Solar Generators

• They operate without requiring fuel, meaning once you’ve purchased the generator, it can provide free energy.
• There’s no need to add or dispose of oil, which means less mess.
• They operate without emissions, which is better for the environment.
• They don’t produce carbon monoxide, and they can typically be used indoors, offering more flexibility.
• They create very little noise, which can be more pleasant for both you and your neighbors if you're using a solar house generator.
• They need only minimal maintenance, so there’s less effort and a lower cost of ownership over time.
• Because they’re lighter than traditional generators, they’re easier to transport to a job site or campsite.

Disadvantages of Solar Generators

• A portable solar power generator doesn’t offer the output of most fuel-powered generators, so it may not be able to power as many devices simultaneously.
• It also may not be able to provide power to appliances or devices that draw a lot of electricity.
• These generators also take time to charge, requiring several hours of sunlight to reach full capacity.
• Since solar generators rely on the sun, you'll get the best charge quality during sunny days.

The running watts — or rated-watts measurement — indicate the electricity the generator can produce continuously. Tally up the wattage requirements of the devices you want the generator to power. You can often find the requirements of an electrical device on the device itself. Make sure the running wattage of the generator is greater than this total.

The watt-hours (Wh) — or capacity — of the generator help make sure it can power devices for the length of time you need. The measurement tells you how much continuous power the generator can provide for 60 minutes with a full battery charge. It also helps you estimate how much power the generator can deliver before needing to be recharged. For example, in the right conditions, a 600-Wh generator could power a 50-watt light for around 12 hours or two 100-watt devices for around three hours before the battery is exhausted. Keep in mind, these calculations are just estimates, and you may not be able to use the full capacity. For example, the temperature can affect the capacity of the battery. Multiply the total wattage of the devices you need to power by the time you need to run them. You’ll need a generator that offers a watt-hours capacity greater than the result.

The peak power output — or starting watts measurement — of a generator indicates the power the generator can briefly provide before settling into the running output. This measurement will be higher than the running watts. This momentary surge of extra power is needed to start an electric motor on devices like a mini refrigerator or a fan. If you’ll be powering a device that has a motor, determine its starting wattage and make sure the peak power output of the generator can accommodate it.

Recharge time gives you an idea of how long it takes to return an exhausted solar generator battery to a full charge. The manufacturer’s documentation should indicate an estimate of charging time based on the charging speed of the generator and the specific power input from solar panels. Keep in mind it’s likely based on the maximum input of solar power, which you can’t always expect. Cloudy weather will impact charging, and you’ll need direct sunlight for best results, so a generator that charges ten hours with a 200-watt solar panel may require a few days to charge fully. Factor this in with the capacity and power needs. For example, if you’re going to be relying on the solar generator to supply power for lights, a portable TV and mobile devices for several days, make sure the capacity and charge rate will give you the power you need during that time. While many models can supply power while charging, this will increase charging time and you might be using power faster than the battery can recharge, making it a good idea to have a spare battery or even a second generator.

Solar generators use devices known as inverters to transform the direct current (DC) power delivered from solar panels to alternating current (AC) power so you can power or charge your devices. A modified sine inverter is an economical option that works with many types of devices. However, others may not operate as well with this type of inverter or may not function at all. A modified sine wave may cause a hum in audio equipment and may reduce the life of other devices, so make sure anything you connect is suited for it. A pure sine inverter is more expensive but will be a better option for some home devices and sensitive electronics.

Solar generators use either lead-acid or lithium-ion (Li-ion) batteries to store energy. Generators with lead batteries will typically be less expensive than those with lithium-ion batteries, but lithium-ion batteries will likely last longer. Lithium-ion batteries also tend to be lighter, which is something to consider if portability is a top consideration.