Can I Run my Device Directly from Solar Power?

Solar Energy. It's an option that is becoming more and more viable as the years go by. Maybe you have a friend who has a small solar panel on the dashboard of his pickup maintaining the battery, or you've read about people who manage to live off-grid, entirely relying on solar energy. Put simply, solar panels - or solar chargers - are straightforward devices that capture rays from the sun and transform them into usable power. But before jumping into the world of solar, there are a few details about solar panels that you ought to know of:

A Solar Panel Can...

• provide electrical current when placed in direct sunlight
• be connected with other panels in series or parallel
• be designed with a glass surface or flexible material

A Solar Panel Can't...

• store electricity to be used at a later time
• output power during the night
• efficiently provide power when placed under flourescent light bulbs

So, with the knowledge gained in the preceding paragraphs, Can you run (enter favorite device here) directly off solar energy? The simple answer is this: Yes and no.

Well, that's not such a simple answer, so here are a few things you need to know that will help explain how the answer can be both yes and no simultaneously.

Most solar panels are rated for 12 volts DC nominal. Nominal in this example means that is what the panel is rated at, but it will likely put out more (or less) voltage in varying situations. Often, solar panels are called “solar chargers,” meant for maintaining or recharging 12-volt batteries. What’s more, most household appliances require a very different voltage than what a solar panel produces and cannot run things like your kitchen blender or plug-in heater. Household appliances and electronics in our part of the world (good ol’ US of A) require 120 Volts AC*, and a solar panel does not meet those power requirements.
**Additional information on how to power 120 VAC devices can be found in our article: Solar Systems the Right Way**

Can I use solar chargers directly without a battery?

Okay, so what can I power directly off a solar panel? Many off-grid homes and camping equipment accessories are designed to run off 12 VDC. However, powering off a solar panel directly may or may not work due to the voltage ranges a solar panel can operate within. If you measure the live power from the solar panel, you can expect voltage anywhere from 12 to 21 volts! This is perfectly normal for solar panels because the power ranges with the intensity of the UV Rays they receive from the sun. The total amount of energy will never exceed the wattage rating of the panel, but the voltage and amperage can increase and decrease accordingly throughout the day. As voltage goes up, amperage goes down. Total power remains the same. Volts x Amps = Watts. This solar calculator comes in very handy when working with solar.

You can run a device off a solar panel if it can handle the fluctuations in solar energy and the panel meets the device's minimum power (amp/wattage) requirements. If you try using a solar panel on a partly cloudy day, you will quickly see that you have full sun one minute, and the next, you have a cloud blocking the sun. These fluctuations can cause large swings of solar energy - one minute, you may have little to no voltage, and the next minute you have full voltage and/or amperage. Simple devices like pumps and fans are less susceptible to damage and more likely to handle these fluctuations. You will see that some of the foldable panels we carry come with cigarette lighter sockets to plug in a 12v car accessory. These panels are popular among backpackers and offer a solution for people trying to charge GPS devices, e-readers, or cell phones.

However, with most modern technology, devices get picky and will shut down if you try to power directly off a solar panel. One issue we have noticed is with certain cell phones; if the solar input fluctuates (partly cloudy), the cell phone cuts the charger off and will not resume charging until it has been disconnected and reconnected.

Make it work with a Solar Charge Controller and a Battery

So, what’s the use of a solar charger? You can get around these issues by installing a solar charge controller and a small battery between the solar panel and the device. The solar charge controller will stabilize the voltage to normal levels, and the battery will stabilize the amperage fluctuations. This then leaves you with the cleaner power that most devices need. Please keep in mind that the small battery is not there to run the load but stabilize the power. If sunlight conditions diminish greatly, the battery may become discharged, defeating the purpose of stabilizing the load. For this reason, it is also recommended to make sure your panel outputs a little more than you need, so it can recharge the battery if required.

All this explains why we cannot give you a firm yes or no answer regarding powering devices off a solar panel. A lot will depend on the device and the voltage ratings it is designed to operate within. So, yes, it is doable, and no, it is not always the solution or as simple as you might have hoped. However, we like figuring stuff out, and we are always happy to help you solve the problem and see if we can work up a solution that meets your off-grid needs.

Summary

If you are looking to power devices on the go, we recommend checking out our solar section. We have plenty of framed solar panels and some very nice military-grade foldable solar panels, and we have the knowledge to get you where you need to be regarding off-grid solar charging.