How to Test Solar Panels Without the Sun: A Step-By-Step Guide

By Kami Turky

Last Updated:

Sometimes, the sun just doesn’t show up when you need it most—like when you’re trying to test your solar panels. 

That’s why I’ve put together this guide on how to test solar panels without the sun. 

I’ve experimented with a bunch of ways to fake sunlight and make sure we can still check if everything’s working right, even when it’s cloudy or you’re stuck indoors. 

In this guide, I’m going to break down the best tricks and tools for testing your solar panels using artificial light. 

You’ll get reliable results, no matter the weather!

Key Takeaways

  • To test solar panels without direct sunlight, you can use fluorescent, incandescent, or LED lights.
  • Fluorescent lights provide steady, broad light but lack the full intensity of sunlight.
  • Incandescent lights are closer to mimicking natural sunlight and are more effective for testing.
  • LED lights are energy-efficient but their focused light is less ideal for simulating sunlight.
  • While artificial lights can show if your panels are working, they won’t match the power and brightness of real sunlight, making them only suitable for quick checks.

What Light Sources Can Be Used to Test Solar Panels?

To test solar panels without direct sunlight, several types of artificial light sources can be utilized, including:

  • Fluorescent Lights: These lights are pretty good for testing because they give off a steady and broad light. However, they don’t quite match the intensity or full range of sunlight.
  • Incandescent Lights: These are a bit closer to mimicking natural sunlight. They emit a spectrum of light that’s more effective for testing solar panels compared to other artificial sources.
  • LED Lights: LEDs are great for saving energy and they come in various types of light spectrums. But their light is more focused and narrow, so they’re not the best choice if you’re trying to imitate sunlight for solar tests.

It’s worth noting, though, that while these lights can show you if your panels are working, they don’t pack the same punch as the sun. 

They just don’t have enough photons to generate more than a small blip on your voltmeter. 

So, these tests are good for a quick check, but they won’t tell you how your panels will perform under sunny skies.

What Equipment Do You Need to Test Solar Panels Without the Sun?

To test solar panels without direct sunlight, you’ll need a few basic tools to get the job done right. 

Let’s start with the light source—you can use a fluorescent, incandescent, or LED light

Choose whichever one you have on hand, or whichever best fits the intensity you’re trying to replicate.

Next up, make sure your light source is hooked up to a reliable power supply. 

This is important because you want the light to stay consistent during your tests. 

A steady light means you’ll get more accurate results, helping you see just how well your solar panels are working under these artificial conditions.

Lastly, you’ll need a multimeter or voltmeter to check how much electricity your panels are producing. 

This is where the magic happens: you’ll connect this tool to your panels, turn on your light, and watch the meter do its thing. 

It’s a simple way to see if your panels are converting that artificial light into power, just like they would with sunlight.

How Do You Perform a Basic Test on Solar Panels Without the Sun?

To test your solar panels without sunlight, you can follow these few easy steps:

1. Connect the Solar Panels: First things first, hook up your solar panels to a multimeter or voltmeter that will tell you if your panels are generating any electricity.

2. Set Up the Light Source: Next, grab a large incandescent lamp and plug it into a power source. I prefer this type of light is great because it’s pretty close to how sunlight works, making it ideal for our test.

3. Illuminate the Solar Panel: Now, turn on your lamp and aim it straight at the solar panel. Make sure the whole panel is bathed in light, just like it would be under the sun.

4. Check the Voltmeter: Take a look at the voltmeter. You’ll probably see a small number since we’re not using real sunlight, but any positive number means your panel is working. It’s converting the light from your lamp into electric power.

What Should You Do If the Solar Panel Shows No Output?

If your multimeter reads ‘0’ while testing your solar panel, don’t worry just yet—there are a few things you can check. 

First off, there’s a chance that your solar panel might not be working right. 

But it could also be that the artificial light you’re using isn’t strong enough to mimic the sun well.

So, what’s next? 

Dive into some troubleshooting. 

Make sure all the connections are tight and correctly set up. 

Sometimes, just double-checking these can solve the problem. 

If that doesn’t work, try switching up your light source or crank up the brightness if you can.

Still no luck? 

It might be time to call in the experts. 

You can reach out to us at Solar Mentors. 

We’re here to help diagnose the issue and get your solar panels back in action.

Related article: How To Increase Solar Panel Output?


How Do You Test a Solar Panel to See If It’s Working?

To test a solar panel, connect the solar panel to a multimeter and expose it to a light source. Check for a positive voltage reading to confirm it’s working.

How to Use a Solar Panel Without Sunlight?

To use a solar panel without sunlight, use an artificial light source like a fluorescent, incandescent, or LED light to generate electricity for basic functionality testing.

How Do You Check If All Solar Panels Are Working?

To check if all solar panels are working, test each solar panel individually with a multimeter and an artificial light source. Ensure each panel shows a positive voltage reading.

Will Solar Panels Work Without Direct Sunlight?

Solar panels will work without direct sunlight or artificial light, but their efficiency and power output will be much lower.


As promised, we’ve gone through all the steps on how to test your solar panels even when the sun decides to hide. 

We’ve looked at which lights work best and how to get your gear ready, so now you can make sure your panels are always doing great. 

Here’s a special tip: keep a log of every test you do. 

It’s super helpful for keeping an eye on how things are going over time, and it might even help you spot small issues before they turn into big headaches. 

If you still need any help or have questions, don’t hesitate to reach out. 

Whether it’s picking the right lights or figuring out how to log your tests, I’m here to help.

Kami Turky

Kami is a solar engineer with nearly a decade of experience in researching, testing, and reviewing various solar products.He has also provided technical consultation to several organizations on the best ways to incorporate solar energy into their operations.When he’s not busy helping others find the best solar solutions, Kami enjoys spending time outdoors, hiking, camping, and exploring the natural wonders of his home state.

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