How Efficient are Solar Panels?

SolarCalendarMarch 8, 2019

We all know that solar panels are growing in popularity, but how efficient are they?

In this article, we’ll try and find out how efficient solar panels are and what factors make them more or less efficient.

How Efficient are Solar Panels?

Solar energy is the most abundant form of energy found on Earth. But how efficient are the solar panels that we use to power residential homes?

Most figures say that solar panels are roughly between 15% and 18% efficient, meaning that 15% to 18% of the sunlight they absorb is converted into electricity while the rest hits the solar panel and warms the surface like it would anything else.

That being said, there are a variety of factors that can change the specific efficiency of your solar panel system.

Factors That Affect Solar Panel Efficiency

There are many different factors that will affect how efficient your panels are. Some of them are external (meaning they have to do with factors outside of your solar energy system) and others are internal (dealing specifically with your solar energy system.)

Here are just a few of the internal factors which will affect your panels 

Solar panel age - Solar energy technology generally, and solar panels specifically, have a long history that reaches back to 1839. Needless to say, there have been countless innovations in the industry that have helped make solar panels more efficient. These innovations have grown exponentially in recent years to the point where clean solar energy is a viable option for many more people than it used to be. Not only are new solar panels going to be more efficient than old ones due to these technological innovations, but they’re also more efficient than used ones because solar panels lose a little bit of efficiency every year they’re used. Your panels will likely still work great as they get older, but they won’t be quite as efficient as when they were new.

Type of solar panels - There are two types of solar panels. There are thermal panels and photovoltaic (PV) panels. Thermal panels are used to heat hot water. Thermal panels directly capture the heat of the sun and operate most efficiently in warmer climates. PV panels simply separate electrons with the energy from sunlight. This electricity is then used to power your home. PV panels are the most common type used for residential solar.

Solar panel materials - There are three materials that solar panels can be made of. There’s monocrystalline silicon, polycrystalline silicon, and multi-junction solar cells. That being said, multi-junction cells are mostly only used on space satellites. Of the other two types of materials, monocrystalline silicon is the more common and more efficient material.

These aren’t all of the factors which may affect your solar panels’ ability to provide your home with clean energy, but these are the factors that directly affect the panels’ efficiency.

Other Factors That Affect Solar Efficiency

Now let’s talk about some of the other factors that can affect the efficiency of your solar energy system. These factors don’t affect the efficiency of the panels themselves, but rather how well your solar energy system will produce power for you to use in your home.

Solar plans - Your solar plan will help determine efficiency in a roundabout way. Rather than increasing or decreasing the efficiency of your solar panels, your solar plan will help determine how cost-effective your solar panels are. You’ll want to find the best deal for you and your specific situation.

Solar energy system design - Design is an important element to solar energy system efficiency. If your solar panels are not set up correctly, it is possible that they will not produce enough electricity to meet your usage needs. This is why we have specialists at Vivint Solar who make sure that your house can accommodate the number of panels you need for the level of usage you require.

Average sun exposure - Some homes receive a lot more sun exposure than other homes. This may be due to a large tree in the yard. It might be because the house is next to a taller building which blocks the sun. It could simply be a weather issue. Some places just aren’t very sunny. It could even be the direction your house is facing or the shape of your roof. Whatever the reason, a change in sun exposure is going to equal a change in solar panel production. These changes can vary greatly from house to house, even if those houses are in the same neighborhood.

Upgrades around the house - Making your home more efficient is another workaround that will help your solar panels get you the energy you need. For example, if you have an electric water heater a lot of electricity goes to heating the water that we use. In some cases upgrading to a heat pump based electric water heater can save energy. Appliances such as dishwashers, washing machines, clothes dryers, and air conditioners all use electricity as well. Each of these appliances should be updated every once in a while. That doesn’t mean you have to get a new one every year, but if you can afford to upgrade them, go ahead and do it. Aside from updates to your appliances, there are plenty of other updates you can make around the house to get the most out of your solar energy system. Look for different ways to make your home more energy efficient to help your house use the energy from your solar panels more efficiently.

These factors will help you determine how efficiently your solar panels can produce the energy you need for your home.

Long-term Factors That Affect Solar Panel Efficiency

The efficiency of your solar panels can also be affected by the way you treat them over the course of their lifespan. Here are some of the long-term factors that can affect their efficiency.

Clean your solar panels - Dirty panels are inefficient panels. Your solar panels can stand to be cleaned every once in a while. Leaves, broken branches, and any garbage that the wind picks up can shade part of your solar panels, causing them to become less efficient. Clean them once a year to prevent this problem from getting worse. Be careful in going up on the roof. In some cases you may be able to spray them from the ground.

Perform regular maintenance - There is routine maintenance that should happen to make sure that your solar panels are working as well as they should be. Make sure you know what type of maintenance is expected of you, and do it diligently so you can have efficient solar panels year-round.

Vivint Solar Is Here To Provide You With Clean Energy

If you’re interested in using clean solar energy, Vivint Solar is the company for you. We have helped thousands of customers convert their rooftops into efficient, energy-producing solar energy systems.

Contact us today to set an appointment with one of our Vivint Solar reps to help you learn whether or not solar energy is the right step for you!

How to Go Solar

Vivint Solar makes renewable energy a simple and affordable alternative. We take care of everything from solar system design, to paperwork and permitting, to installation and maintenance.

Get a free estimate