Is Your Home Too Shaded for Solar Power? What You Need to Know.

 

Solar panels have been around long enough for homeowners to realize that the benefits often outweigh the cons. However, before asking yourself if they will generate enough electricity and who you should buy the system from, it’s important to figure out if solar panels for your home even make sense.

One quick way is to step outside and check for any signs of roof shading. Regardless of the source, it’s important to check for roof shading because it can have a tremendous impact on your solar panel output efficiency.

In other words, the number you get when you use a solar ROI calculator may not be entirely accurate unless you account for the decreased efficiency whenever your panels are shaded.

However, it’s not the end of the world if you have a shaded roof. There are solutions you can employ to optimize your solar panel output or avoid shading altogether.

Do Solar Panels Operate in the Shade?

If your solar panels are covered with shade, the good news is that they will still work and put out a decent amount of electricity. However, the output will be much less due to the decreased solar exposure.

Unfortunately, there isn’t an exact figure for how much less electricity you will get. The general rule of thumb is that solar panels will produce about half the amount as they would with direct sunlight.

 

What Causes Solar Panel Shade?

Solar panel shading, whether in the city or for off-grid solar systems, can come from a multitude of sources.

Trees are the most common reason your solar panel system will have any shading issues. Most homes situated in green spaces will have ever-expanding rows and clusters of trees and foliage that cover up solar panel installations.

Fortunately, in many cases, homeowners do not have to cut down age-old and environmentally-friendly trees. Oftentimes, all that’s required is routinely removing or trimming a few branches.

Clouds are another reason for solar shading and one that’s entirely out of your control as a homeowner. Despite the fact that clouds block sunshine, it’s one source of shading that you won’t have to worry about.

That’s because clouds still allow some sunlight through, and solar panels can still generate power with indirect sunlight. In fact, cloudy days that lead to rain can help your panels operate even more efficiently when it clears up.

This is due to the rain washing away dirt and debris that collects over time.

Roof structures can also cause your solar panels to be shaded. Depending on the time of the day and the angle of the sun, varying structures like your chimney can block sunlight to portions of your solar array. The roof structure is an important factor to consider before installation.

Generally, installing solar panels on South-facing roofs is ideal. Sun movement throughout the day will not only cause shading from structures like a chimney or dormer but also will provide less sunlight to East or West facing panels.

Fortunately, as long as you work with an experienced solar installer, they will be able to take all this into consideration and place the panels in areas where they will receive the least amount of shading.

Solar Panel Efficiency

As briefly mentioned earlier, shaded solar panels will produce significantly less power compared to when they receive direct sunlight—about half as much.

Fortunately, in addition to trimming a few branches, you can focus on aspects of your installation’s design to help avoid reduced output—specifically the type of solar panels and the inverters used.

Every single solar panel system available will use some kind of inverter to convert DC into usable AC. Choosing the right solar inverter is crucial in minimizing efficiency loss.

String inverters are the most basic and most commonly found inverter on the market. If your system uses a string inverter, then that means all or most of your panels are connected to a single inverter.

That translates to your entire system having a maximum capacity or power output of the weakest panel. For example, if a tree casts shade over one panel, the entire system will only be as efficient as the shaded panel.

Microinverters are used when you want a system that has one inverter per panel. They essentially look and operate like a long string of Christmas tree lights.

For example, if one panel gets shaded, the rest of your panels will still operate at peak efficiency due to having an individual inverter assigned.

Lastly, there are power optimizers. These can be seen as a cross between micro and string inverters. Power optimizers will condition the DC electricity from each panel and send it to the string inverter. This conditioning is why your solar system can operate as if it uses individual microinverters.

If you live in a cloudier location or have a bunch of trees you don’t want to cut down; it’s best to consider installing a solar power system that uses microinverters or power optimizers.

It is a slightly more expensive option but well worth the near-constant peak electricity production.

Harvesting Solar Power Energy in the Shade

There are many variables to consider when it comes to installing your first solar panel system. Shade is one of those variables, and it’s a genuine cause for concern.

However, the output variations and the random dips in efficiency can be easily minimized with the right layout and inverter. Many solar installers can create customized layouts to help avoid shade as much as possible.

Before committing to the first installer you come across, consider shopping around and asking how each installer plans to avoid potential shading problems for your solar panels.