Need outdoor power for camping or looking for a home emergency backup power? A portable solar generator provides power on the go and can keep key home devices running in a power outage. Here are some tips for how to find the best solar generator for your needs.
Sizing a Solar Generator
As with any generator, you need to make sure the portable solar generator system you purchase will give you the power you need. There are several measurements that’ll help. Researching with these in mind will help you choose the right generator for your needs.
Running Watts
4 Sunpower 100 solar panels and a OXTECO Sirius2500w solar generator powering a projector and lights for a family in a yard.
The running watts — or rated-watts measurement — indicate the electricity the generator can produce continuously. Tally 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.
Watt Hours
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.
Peak Power
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
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.
Good to Know
Temperatures below 32 degrees Fahrenheit may reduce battery capacity, and you may not be able to charge the battery in these conditions. Check the generator’s manual for tips on using the generator in subfreezing temperatures.
Other Considerations
In addition to properly sizing your generator, there are some other factors to consider.
Inverter Type
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.
Battery Type
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. Nowadays, the LipoFe4 battery can offer a longer circle time. It will be a a better choice now.