WHY DOES SOLAR PANEL EFFICIENCY MATTER?
There are many factors to consider when choosing a solar panel system for your home. Ultimately, you want a setup that’ll maximize the amount of solar output delivered to your home. Carefully weighing the main factors will help you make the right choice. One of these factors is solar panel efficiency.
This property affects the performance of solar panels. It helps determine how efficient they are at doing their job ― that is, collecting sunlight and transforming it into solar power. The more efficient solar panels are, the less panels you’ll need to adequately power your home.
Solar arrays (another name for a solar panel system) are available in different sizes to account for varying roof space and energy needs. Solar panels with a high efficiency rating allow homeowners with small roofs to install a modestly sized array that meets their energy production needs.
Still have questions? Fortunately, we have the answers to common questions about solar panel efficiency, including:
- What is solar panel efficiency?
- What factors affect efficiency?
- How efficient is the average solar panel?
- Why should you account for your roof’s peak amount of sunshine?
- What can you do to improve the efficiency of your solar panels?
- Do solar panels become less efficient over time?
Which solar panels are most efficient?
To get the answers, all you need to do is keep reading.
1. WHAT IS SOLAR PANEL EFFICIENCY?
Let’s break it down.
Solar panel efficiency is a measurement of how much sunlight a solar panel can convert into a usable electric current. For example, when the sun shines on a high efficiency solar panel with a 20% rating, it’ll convert 20% of the sun’s energy to solar power. A solar panel with 20% efficiency will produce more electricity than a solar panel with 15% efficiency, even if they receive the same amount of sunlight.
In terms of efficiency, a higher rating is always better.
2. WHAT FACTORS AFFECT SOLAR PANEL EFFICIENCY?
Solar panel efficiency depends on the production of electricity by solar cells. The amount of electricity production is influenced by each cell’s:
- Composition ― Photovoltaic (PV) cells are composed of silicon, a semiconductor material that absorbs sunlight that strikes the solar panel. In this way, the semiconductor material of the cell receives the energy provided by the sunlight.
- Electrical configuration ― Each PV cell has one or more electric fields that forces electrons to flow in a certain direction, creating a current. Together with the cell’s voltage (which originates from the cell’s built-in electric fields), the current determines the wattage produced by the solar cell.
- Surrounding components ― Since silicon is a reflective material, an antireflective coating is essential for improving the amount of sunlight the cell absorbs. Once they have enclosed each cell in a protective glass cover plate, solar panel manufacturers connect individual cells to produce effective current and voltage levels.
3. HOW EFFICIENT IS THE AVERAGE SOLAR PANEL?
As of May 2022, the most efficient solar panels on the market are approximately 23% efficient. Although 23% efficiency might seem low, keep in mind that most cars run on internal combustion engines that are approximately 30% to 35% efficient, and you have to pay for every gallon of gas.
Solar energy, on the other hand, is virtually free aside from the cost of your solar array ― and it can reduce or even eliminate your electric bills. That’s a pretty substantial benefit given the average efficiency rate.
4. WHY SHOULD YOU ACCOUNT FOR YOUR ROOF’S PEAK AMOUNT OF SUNSHINE?
In general, the less peak sunlight your home receives, the greater the need for solar panels with a high efficiency rating. This is especially true if your roof is on the small side.
Peak sunlight refers to how many hours of sunshine your roof gets each day. The amount of peak sunlight received varies from home to home. Factors that influence peak sunlight include:
- Geographical location within the U.S.
- Direction in which the roof faces
- Interference from trees and structures
You can get a better idea of how much sunlight your roof gets, based on your home’s geographical location, by referring to this resource from the National Renewable Energy Laboratory. And if you still need help calculating your home’s amount of peak sun hours, one of our solar energy specialists would be happy to assist!
5. HOW CAN YOU IMPROVE THE EFFICIENCY OF YOUR SOLAR PANELS?
While it might not make a huge difference right away, there are actions you can take to increase how much sunlight your solar panels convert into usable electricity. These small measures can add up over time and end up making a significant impact in the long run.
Actions that can improve the efficiency of your solar array include the following:
Get them professionally cleaned
As dust accumulates on your panels, it can compromise their efficiency, reducing their output. That said, if you live in an area that receives regular rainfall, or if your panels are installed on a tilted angle, cleaning them might not be necessary.
Remove overarching branches
Solar panels perform at their optimum level when they’re exposed to direct sunlight. You might not be able to cut down an entire tree, but you can remove overarching branches.
Consider a solar battery
A solar battery allows you to store excess solar energy your array generates. You can then use this stored power at night, on days with minimal sunlight and during power outages.
6. DO SOLAR PANELS BECOME LESS EFFICIENT OVER TIME?
Not exactly ― but their performance does degrade as they age. And as this happens, your array will produce a little less solar power. Now, keep in mind that the average solar panel degradation rate is only about 0.5% per year. Some panels will degrade more slowly, while others will degrade faster.
Let’s use an example to illustrate the process. A 6 kW solar power system located on a home in Massachusetts, composed of panels that degrade at 0.5% per year, will:
- Experience a decrease of 30 to 40 kilowatt-hours (that is, the amount of electricity they produce) per year
- Produce approximately 6,890 kilowatt-hours by the time they’re 25 years old
At this slow degradation rate, solar panels could still operate at an impressive 87.5% at the very end of a 25-year lifespan. Premium solar panels could retain an even better operating rate. When you consider that many solar arrays last anywhere from 25 to 50 years, chances are good that the efficiency of your panels will suffer very little depreciation.
7. WHICH SOLAR PANELS ARE MOST EFFICIENT?
The majority of residential solar panels on the market today fall into one of three categories:
- Monocrystalline ― Highest efficiency ratings, at 17% to 22%
- Polycrystalline ― Mid-range efficiency ratings, at 15% to 17%
- Thin film ― Lowest efficiency ratings, at 10% to 13%
Yes, efficiency is an important property when it comes to choosing solar panels. But you shouldn’t make a decision based on efficiency rating alone. Additional factors, like durability, determine whether one of these solar panel types is the best fit for your needs.
STILL UNCERTAIN ABOUT SOLAR PANEL EFFICIENCY? A SOLAR SPECIALIST CAN HELP!
If you still have questions about solar panel efficiency, don’t worry ― one of our solar specialists would love to help! We can help guide you towards the array that’ll offer better efficiency for your home.
When you choose a solar power system from ADT Solar™, you can rest assured you’re in good hands. Leveraging more than 147 years of experience, we help protect customers with home security solutions, keep them connected with smart home solutions and empower them with solar energy for their home.
From the placement of solar panels on your roof, to the quality of the panels themselves, we’ll go the distance to maximize the efficiency of your solar array.
As part of our unwavering dedication to customer service, ADT Solar offers warranties and guarantees that are among the best in the industry. The high quality arrays we install are designed to last for decades. For that reason, we are confident about standing behind our products with the following:
- 25-year labor guarantee
- 25-year power production guarantee
- 25-year Enphase microinverters guarantee