Updated January 15, 2022
A good solar panel system can save you a small fortune on your monthly power bill. Besides this, it’s good for the environment. But from time to time, your solar output might decrease, and you’ll need to diagnose the issue. So, how can you tell if your solar panels are working?
To find out whether your solar panels are working, you’ll have to work through a series of checks. Your solar panel output could drop for a number of reasons. The panels might not be getting enough sun, or there could be an issue with your inverter. The goal here is to find out where the problem lies.
Here are seven steps to determining whether or not your solar panels are working.
Table of Contents
Step 1: Check Your Breaker Box
This might sound absurdly obvious, but you could have tripped a circuit breaker. The switches in your breaker box are designed to protect your home’s circuitry and electronics. If there’s a power surge, or if one of your appliances tries to draw too much power, the breaker will trip. If that happens to the circuit connecting your solar system to your home’s power, your panels won’t be providing any power.
So, head to your basement or utility room, open up your breaker box and take a peek. If the breaker has been tripped, reset it. Chances are, that will solve your problem.
Step 2: How’s the Weather?
Another potential issue is the weather. Your solar panels rely on sunshine to produce energy, and their performance drops when it’s cloudy or rainy. This isn’t to say they stop working entirely, but in foul weather, your energy output will only be around 10 to 25 percent of the system’s maximum.
Even if your area is particularly cloudy, solar power can still be a worthwhile investment. San Francisco has one of the highest solar power capacities in the nation, despite being notoriously foggy.
Unfortunately, there’s not much you can do about your local weather. But if your solar panels are consistently underperforming, this could be the cause.
Step 3: Are the Panels Clean?
Modern solar panels will normally remain clean, provided there’s consistent rainfall to wash away dirt and debris. So under most circumstances, you shouldn’t have to worry about this. That said, you might be dealing with tree sap, or you might be in the middle of a draught. Take a look at your solar panels, and see if they’re dirty or clean.
In most cases, all you’ll need to do is hose the panels down, which you can do safely from the ground. But if the dirt is particularly stubborn, don’t go up on your roof and start scrubbing. This could be dangerous, and it’s better to hire a professional.
Step 4: Are the Panels Shaded?
When you installed your solar system, you probably put it in the sunniest possible place. And if it’s a rooftop system, you probably took the time to have tree branches trimmed away. But over time, trees may have grown out, or you may have installed a satellite dish that casts a shadow. This won’t always be apparent at all times of day; as the sun moves around, so will the shadows. Check it multiple times of day to see what’s going on.
If it turns out your panels are getting shaded, it’s time to take remedial action. Remove any obstructions, or trim away any new branches that have grown. This could require diplomacy if the obstruction is on a neighbor’s property.
Step 5: Check Your Inverter
The next thing to check is your solar inverter, which is the big box that your solar panels are wired into. Different inverters have different designs, depending on the manufacturer. However, what you need to be looking for are the status lights. When the inverter is working correctly, the light will be solid green.
If the light is red or orange during daylight, there’s a fault somewhere in the system. This could be because the grid voltage is too high or too low, or because there’s a ground fault. It could also be because you tripped a breaker, but you already checked that.
If the light is flashing red or orange, the inverter is experiencing an error. Look for a display with an error code on it. You might be able to find the code in your inverter’s manual, or on the manufacturer’s website. Otherwise, you’ll need to call customer support.
Step 6: Check Your Solar Output
Assuming your inverter is working correctly, the next step is to see how much power your system is outputting. You can do this directly on some inverter models if the output is shown on a digital display. Otherwise, you’ll have to go online and access the information through your solar provider’s portal. This will usually provide more detailed information than the display alone.
Here’s what you should be looking for:
- Your system’s current output, in kilowatts (kW). Keep in mind that if it’s dark out, this will be zero. You’ll need to check this during the daytime, on a sunny day.
- The total power produced per day, in kilowatt-hours (kWh). Check this after sunset, so you’re getting an accurate total.
- The total energy produced since the system’s installation, in kWh.
If your solar system has an online portal, you might be able to compare your output from month to month, or even from week to week. That way, you can see if your production has dropped off. If your system is brand new, you can compare your output to your solar provider’s estimate, instead.
Step 7: Check Your Electric Meter
If you’ve gotten this far, your solar system itself is functioning properly. But there might still be a problem with your connection to the grid. To find out, you’ll want to check your home’s electric meter.
This meter belongs to your utility company, and it measures how much power you’re drawing from the grid. Assuming your usage stays constant, this amount should drop during daylight hours.
So, get up early in the morning, before it’s light, and see how much power your house is drawing. Then, check again after dawn, and see if that number has changed. If you’re still drawing the same amount of grid power, call your solar provider and ask them to send a technician
Don’t Count on Your Electrical Bill
One common mistake people make is to rely on their electrical bills. In fact, 46 percent of solar owners wait until their bill arrives to find out if there’s a problem. This is a bad idea for a couple of reasons.
To begin with, your power bill won’t show you how much your solar system produced, or how much of that energy went into your house. It only shows the amount of power you’ve fed into the grid, and how much you’ve bought from your utility company. If you’ve started using more power, you’ll be feeding less into the grid, even if your solar system is working just fine.
Another issue with relying on your bill is that you’re not getting the most up-to-date information. If your breaker tripped or your inverter has an error, you could be drawing grid power for an entire month before you realize something is wrong. And if you receive a quarterly power bill, you might end up paying for a full three months of grid power.
Finally, solar output naturally fluctuates with the seasons, as does our energy use. So comparing your bills from month to month is not a reliable measure of your system’s effectiveness. If you’re going to compare bills, compare this month’s bill to the bill from the same month last year.
Conclusion
Finding out if your solar panels are working doesn’t have to be difficult. Yes, some of the solutions could require the help of a professional. But by working through these seven steps, you can quickly and easily find any issues in your solar power system. At that point, you’ll at least understand what’s going on, and what steps you need to take.
