Do you need to monitor your solar panels?
It’s easy to think, “Solar panels work when the sun’s up and stop when the sun goes down, easy peasy. What’s there to monitor?” Even taking a glance at your solar production, it looks pretty self explanatory. Well, I am not here to say that it’s hard but there are more factors than you may think that go into the performance and energy generation of your solar system. By understanding what is affecting their production, you will be further equipped to understand how they are performing and how to care for them to make sure you are getting the most out of their ability day to day and throughout their effective useful life or how they are analyzed.
Solar Panel Equipment
Efficiency
Do all panels have the same efficiency?
The first on this list is of course the equipment themselves.
Even to an Energy Engineer, looking from rooftop to rooftop, generally speaking, solar panels all look the same. It’s difficult to tell when they were manufactured or which manufacturer they came from. Though solar panels havent changed much in how they look over the years or even where they come from, there is a difference in efficiency between types and manufacturers. Over the years, manufacturing processes and technologies in the materials have greatly increased in how efficient the panels are in producing energy from the amount of sunlight they receive.
This forbes article, though a couple of years old now is still relevant, talks about how solar panels will continue to improve. So don’t be fooled, not all solar panels are the same.
If you are in the market to purchase panels, talk with a trusted Energy Engineer or Solar expert to get more information of what type of panels are right for you. Or send me an email with your question, I would love to help.
Age & Effective Useful Life
Do Solar Panels move?
Okay, so you already have solar panels, maybe you already have them for a few years, or you’re an engineer who’s been asked to look at an existing system. Just like any other piece of technology, age affects their efficiency as well. But they are just sitting there and have no moving parts, what could possibly be wearing out?
Two things actually.
To the naked eye nothing in moving; however, a bit of chemistry is happening between those silicon sandwiches. When sunrays, filled with photons, shoot down to hit the panels, electrons are excited between a positively charged phosphorous layer and a negatively charged boron layer of silicon. These excited electrons create a chain reaction to neighboring electrons, and this my friends, is electricity! One great resource to learn more about how stuff works is How Stuff Works, check it out. Over time these materials wear out and don’t move as efficiently compared to their more younger years…I think we, as people, can relate a bit too well.
Additionally, heat has a great impact on the panels degradation over time. Not only is there heat from the sun hitting the panels, there is heat generated from the exited electrons. Heat is somewhat of a catch-22 because though heat comes from the sun, it is required to excite the electrons, and though the excited electrons create heat, they are creating the electricity. However, it should be noted that heat from the location affect the panels well. Panels that are put in the desert will degrade faster than panels in a cooler climate. Technology advancements have reduce heat degradation through more heat resistant materials or even adding cooling coils to the underside of the panels to improve efficiency.
Other System Equipment
Inverters and Wires
The solar panels aren’t the only equipment in determining the efficiency of the production. You have the wires connecting the panels and the inverter. Some simple things that affect production are the secure connections and string/wire configuration. Loose connections will of course decrease efficiency. Longer wires from the panels, to the inverter, to the meter will decrease efficiency. Finally, the inverter efficiency as well. The inverter converts the panel electricity from AC to DC and this conversion has some energy loss. This is why if the solar panels are being upgraded, it is often recommended to upgrade the inverter as well.
A solar specialist will help determine the best set up for your solar system.
External Factors
Uncontrollable...somewhat
Beside the system configuration, selection, and inevitable degradation, there are additional external factors that effect energy production as well.
The obvious one is weather, if there is no sun, there is no energy production. But within that same idea, sunlight presence, there are other things that affect how much sun the solar panels receive.
Shade cover, trees and neighboring buildings are important when determining where to put panels. Cloudy days are bound to happen but a common conundrum is deciding whether a solar system is worth cutting down a tree. You’ll be asking yourself, “Is going green, worth cutting down green?”.
The angle of the sun’s rays against the panels. The most production is created from perpendicular rays against the panel. If you live in the United States, the equator is to the South. Therefore, a south facing panel in the United States will produce more energy than west or east facing panels. A Solar Panel Designer will determine whether it is good enough to put the panels against the roof or set them at an optimal angle based on your location. Particularly on a flat roof, it may be more advantageous to angle the panels to get the most sun throughout the day.
You may also notice that your system produces more energy in the summer than winter. This is because the summer has longer days and the sun is higher in the sky.
Controllable...bird poop eclipse?
Lastly, cleaning and maintaining the solar system. Dust, leaves, and bird droppings all affect panel efficiency. It is recommended that the panels are cleaned at least once a year; however, it may be more depending on how polluted your area is. Remember when we talked about excited electrons? Well, to an itty bitty electron a dust particle can create a shadow, nevermind a leaf or the aftermath of a bird’s dinner, that’s basically a solar eclipse for that electron.
A simple water and soap solution with a sponge and towel can do wonders for your panels. Rain, can wash some of the dirt away; however, even rain carries dirt along with it. Would a car guy call his car clean after being out in the rain? I know my husband wouldn’t leave his 1963 Ford Falcon in the rain, that’s why we bought a house with a garage. That’s not to say you need to treat your panels the same as a vintage car, but over time the dirt builds up and the cleaner you keep the panels the more you get out of them.
By monitoring your panel efficiency, you can determine how they are performing. If it’s been a year or more since you’ve last cleaned them, compare their performance before and after a good scrubbing, you may see anywhere from 5 to 25% difference in efficiency depending on how dirty they are. Monitoring your panels can help you determine when something may be wrong as well. If there was a dramatic change in production you will know to call a technician to see if a connection has been lost or a panel stopped working.
Let me know in the comments, did I miss anything else that affect solar production? Do you have any maintenance questions? Have you had to decide whether cutting down a tree was worth putting in a solar system?