As you begin evaluating the solar panel options that are available, you may find yourself feeling overwhelmed. There are lots of different factors to consider while shopping for solar panels, including efficiency, cost, payback period, solar panel reviews comparisons, and solar panel ratings just to name a few.
If you’d like some help with understanding how solar panel efficiency and other factors impact your purchasing decision, keep reading. We’ve put together all of the information that you need to know about these topics to make the correct investment for your needs.
Let’s get started.
How efficiency impacts a solar panel rating
Solar panel efficiency ratings matter because they directly impact how much power you can expect to receive from your residential solar system. Efficiency, in this context, is a measurement of how much power your solar panels generate per the amount of light energy that hits their solar cells.
As of 2021, the average rate of efficiency for solar panels is between 15 and 20%. This is generally the range that you want to shop in if you’re looking for new solar panels. Anything below the range will produce less solar energy, which means you wouldn’t save as much on your monthly electricity bills.
What is solar panel efficiency, exactly?
Solar panel efficiency is a measurement of how much power a solar panel can generate with a given amount of sunlight.
For example, imagine that two different solar panels receive 1,000 watts of sunlight each. Panel A creates 200 watts of energy out of that sunlight, while panel B creates 150. In this scenario, panel A would be the more efficient product.
Solar panel efficiency through the years
The average solar panel efficiency rate is currently between 15 and 20%. However, solar panels haven’t always been this efficient.
The efficiency of solar panels has increased significantly over time. When the first modern solar panel was invented by Bell Labs in 1954, it only had an efficiency rating of 6%.
Now, prototypes are being created that can provide up to 30% efficiency in optimal conditions. And there are consumer-ready high-efficiency models available that can achieve up to 25% more electricity than low-tier residential solar panels.
Factors that impact solar panel efficiency
The biggest factor that goes into determining the efficiency of a solar panel is how it’s made. The parts, design, and manufacturing processes that are used to create the panels will all have a direct impact on how efficiently they’re able to generate energy for your home.
All manufacturers prioritize efficiency. But some balance it against other factors like cost, whereas others only care about maximizing efficiency.
Solar panels need to be maintained well in order to retain as much of their efficiency as possible for as long as possible. Generally, this just means keeping them clear of debris and cleaning dust and dirt off of them every six months or so. As long as you do that, you should be good with efficiency from a maintenance perspective.
Local climate conditions
Climate also has a big impact on solar panel efficiency. Your solar panels need to be exposed to the maximum amount of solar radiation for the maximum amount of time in order to be as efficient as possible.
Certain climates are better suited for this than others. If you live in an area that allows you to optimize the orientation and inclination of your panels, then you should get better efficiency from them.
The efficiency of solar panels decreases as the temperature gets hotter. So you should get more energy from them on days when it’s 80 instead of 100.
This factor ties back into your local climate conditions as well. If you live in a region that experiences heat waves above 80 often, your solar panels will likely be less efficient than they could be.
Why finding high-efficiency solar panels matters
Solar panel efficiency matters because it directly impacts how much usable energy a residential solar system produces. And that influences a few key things.
First, if you buy a solar system with more efficient panels, you need fewer panels to generate the power that your home needs.
Second, the more power your solar system generates, the less energy you need to pull from the utility grid. That means you’ll typically save more on your monthly energy bill if you have high-efficiency solar panels as well.
Cost vs. efficiency
Solar panel efficiency is super important to consider when evaluating which solar panels are right for you. However, you need to balance it against cost while you do your shopping.
It only makes sense to spend more on high-efficiency solar panels if you believe the extra cost of those panels will be made up over time through increased savings on your utility bill.
For example, you might determine that a set of high-efficiency solar panels will save you an extra $50 on your utility bill each month. And maybe these panels cost $5,000 more than a standard residential solar system.
If so, it would take 100 months, or about 8.3 years, for you to break even on the extra amount you paid for high-efficiency solar panels. When you consider that solar panels typically last between 25 and 30 years, this purchase makes sense.
But now let’s imagine that the high-efficiency solar panels you’re looking at will only save you $10 per month. In that case, it would take over 41 years to break even. So it wouldn’t be worth it for you to pay extra for the increased efficiency.
Factors to consider while looking up solar panel reviews comparisons
Reading through solar panel ratings and solar panel review comparisons is a great way to find the right residential solar system for your goals. But to get the most out of this method, you need to have a process that you follow to compare the same factors across each solar panel review.
In this section, we’ll cover the five factors that matter most when reading solar reviews.
Some companies that conduct solar panel reviews will offer a baseline rating of panels. These can be useful to get a quick glimpse at how a particular panel stacks up to the competition.
However, it’s not a good idea to use a single rating as your sole indication of whether a panel is worth considering or not. You still want to look into the factors that went into the overall rating for the panels so that you can get a better idea of whether the option could work for you or not.
For example, your goal with solar panels might be to take your home off of the utility grid. If so, some solar panels that receive a lower overall rating may be a better fit for your needs than those with a higher rating.
Durability is very important as well when evaluating solar panels. Most residential solar systems are projected to last between 25 and 30 years. But the efficiency of solar panels drops by about 1% each year.
If you see lots of reviews for a solar panel that says it’s constantly in need of repairs or it’s losing efficiency at a more rapid rate than normal, you may want to bring your search elsewhere.
Solar panel brand names only matter up to a point. Generally, it’s good to buy from brands that have been in business for some time and have earned a solid reputation in the industry. Purchasing from these types of companies will give you peace of mind that your warranties will be honored and the panels themselves will be durable.
But you don’t necessarily have to buy from the biggest names in the industry. Doing so may cost you more than the benefits that you get out of it are worth.
For example, it could be a smart decision to buy panels from an up-and-coming brand if they’ve received lots of positive reviews for their products. Doing so could save you money without impacting your solar panel efficiency in a meaningful way.
It’s also important to think about power output when evaluating solar panel reviews. Residential solar systems usually produce about [250 watts of power](https://us.sunpower.com/how-many-solar-panels-do-you-need-panel-size-and-output-factors#:~:text=Conventional%20solar%20panels%20usually%20produce,wattage%20requirement%20(see%20question%20No.) per panel per hour of direct sunlight. That translates to about 500 - 550 kWh of power per panel per year.
The average home uses about 12,000 kWh of power in a year. If you use an average amount of energy, then you would need around 20-25 panels to satisfy all of your energy demands for the year.
But that number could grow larger or get smaller depending on the power that each panel is able to produce. Keeping these calculations in mind while you shop will help you make sure you get a solar system that can meet your needs.
Cost is obviously always an important factor to consider when making a large purchase such as buying solar panels. But the ideal way to think about cost when it comes to solar panels isn’t to simply purchase the cheapest panels you can find.
Instead, it’s smart to come up with benchmark numbers for what you need your solar system to achieve in a year in terms of power production. Once you have that figure in mind, you can compare systems that meet this benchmark and use cost as a way to differentiate between them.
Picking the best solar panels for your needs
There are three main types of residential solar systems. By understanding which type you want to add to your home, you’ll make it much easier for yourself to figure out the specific panels that are right for you. That’s why this section will provide an overview of the three major types of solar panels.
Grid-tied systems are connected to the utility grid. They let homeowners swap between using solar and electricity to power their homes based on the availability of solar power at any given time.
Connecting your solar system to the grid will also enable you to take advantage of net metering if it’s available in your area. This is a billing practice that enables you to send excess solar power into the grid and get credits on your electricity bill for doing so.
Grid-Tied Systems with Battery Backup
Grid-tied systems are also often used in combination with a battery backup. Solar batteries are a way for homeowners to store the excess energy that their panels produce and use it later. Adding one to your home energy system could save you even more on your electricity bills.
Off-grid systems are not connected to the utility grid. They give homeowners complete energy independence. However, if you choose an off-grid system, you will likely want to add at least one solar battery to it.
That’s because, with an off-grid system, you don’t get the option of swapping back and forth between electricity and solar energy to power your home. You need solar batteries or generators to ensure that you have access to energy when the sun isn’t shining.
Top solar panel options of 2021
There are tons of solid solar panel options on the market in 2021. Here are some of our favorite brands at the moment and what we like about them:
- LG - excellent reputation
- Panasonic - Fantastic technical specifications
- Trina Solar - Excellent value and great performance metrics
- Canadian Solar - Excellent value
- SunPower - Some of the most efficient solar panels on the market
Highest efficiency solar panels of 2021
For residential solar panels, any efficiency level above about 20% is considered high-efficiency. If that’s what you’re after, these are the 2021 solar panels that you should be looking into, sorted by efficiency level:
- SunPower’s Maxeon 3 - 22.8%
- LG Neon R - 22.0%
- REC Alpha Pure - 21.9%
- Panasonic EverVolt - 21.7%
- Silfab Solar Elite BK - 21.4%
- Trina Solar Vertex S 21.1%
Do you need the most efficient solar panels?
Just because it’s possible to purchase solar panels with the highest levels of efficiency doesn’t necessarily mean doing so is right for you. Every person has their own ideal solar system and the one that’s right for you will vary based on factors like how much you want to spend and how much you think you can save by swapping to solar.
Depending on what you’re looking for, it may or may not make sense to get the most efficient solar panels possible.
To figure out what efficiency is right for you, you need to compare the extra price of the more efficient solar panels against the impact it will have on your monthly energy bill. We’ve outlined how to do that in the cost vs. efficiency section of this article.
Solar panel efficiency in the future
One thing to keep in mind while thinking about all of this is that solar panels are likely to continue getting more and more efficient as we move into the future. And as that happens, the cost of panels that are currently priced for high-efficiency will go down.
That means you may be able to pay less for high-efficiency solar panels if you’re willing to wait a few years to buy. However, you would also forgo a few years of solar savings if you decided to do this.
The bottom line on high-efficiency solar panels
High-efficiency solar panels help homeowners save even more on their monthly utility bills. But they also cost more than solar panels with standard efficiency and the exact benefits that you get out of high-efficiency panels will vary based on factors like your location and the unique features of your home.
So make sure to use our site to do you research before selecting the type of solar panel that’s right for you.