Solar panels are essential for your solar power system, without them you can convert the energy from the sun to electricity. In today’s post, I am going to give you my opinion on how you can select the best solar panels for homes.
You can use these recommendations to select solar panels for your own home or your customer’s home.
Factors to consider when selecting the best solar panels for homes
When you are about to select the best solar panels for homes you need to consider these 5 factors, the type of the solar panels, the price point, the warranty period, the durability, and the efficiency.
Depending on your location, the type of your home (if it is a static home or mobile home), the weather conditions, and your financial situation you can find the best combination between these factors that suits what you need.
Factor #1: Types of solar panels
For residential installations, there are mainly three types of solar panels in the market, monocrystalline, polycrystalline, and thin-film solar panels.
Monocrystalline solar panels
A monocrystalline solar panel is a solar panel comprising monocrystalline solar cells. These cells are made from a cylindrical silicon ingot grown from a single crystal of silicon of high purity in the same way as a semiconductor.
They are the most efficient solar panels compared to the other two types, hence they are more expensive.
Polycrystalline Solar Panels
Polycrystalline Solar Panels are also made by using silicon. These are multiple pieces of silicon that are melted, treated, and molded into uniform rectangles.
These panels are less efficient than the monocrystalline solar panel, hence are cheaper, they have an efficiency between 15% to 18%.
Thin-film solar Panels
These are also called Amorphous solar panels. They are the least expensive, and also the least efficient.
Thin-film solar panels are made from a photovoltaic substance that is applied to a substrate like glass.
These are mostly used in mobile homes as they are flexible and you can even fold them.
Factor #2: Price point
Another thing to consider when selecting the best solar panels for homes is the price, this is the tricky one, the higher the efficiency of the panels, the higher the price, also the price can depend on things like the reputation of the solar panel manufacturer, and the durability and the warranty offered.
Since this factor consider how affordable is the solar panel to you, my recommendation is to compare solar panels using the rest of the factors, rank them from number one to five then pick the one you can afford according to your financial situation, if financing is not the problem go for the best one.
Factor #3: Warranty period
Most of the best manufacturers offer a considerable large warranty period, the industry standard is 10 years.
From my experience, most solar panel investments have a return of investment period of between 4 years to 8 years, which means the solar panels will pay back your money ( in utility bills savings) while they are still under warranty.
In the table below I compare some of the best solar panels manufacturers and the warranty period they offer.
|Solar Panel Manufacturer||Warranty Period|
|LG Solar||25 years|
|Mission Solar||25 years|
|LA Solar Group||25 years|
As you can see on the table above all big solar panel manufacturers offer 25 years of warranty, in this factor you can not go wrong.
Factor #4: Solar panel efficiency
Solar panel’s efficiency is it is the measure of how much energy it receives from the sun is converted to electrical energy.
This is important, especially in areas where there is not enough sun or if you have a small roof, you need a solar panel that will give you higher electrical energy per square meter.
Here is the table of some of the most efficient solar panels in the market.
|Solar Panel Manufacturer||Solar Panel Efficiency|
My recommendation is that pick any solar panel with efficiency higher than 20%, in this category the best solar panel is Sunpower A-Series residential solar panels.
Factor #5: Temperature coefficient
The temperature coefficient is how much or how little the solar panel productivity is decreasing when the external temperature rises.
This is the part most people get wrong, the solar panel is most efficient at the lower temperatures, and when the temperature increases the productivity will go down.
In this table, I am going to show the top 5 residential solar panels according to their temperature coefficient.
|Solar Panel Manufacturer||Temperature Coefficient|
Here the most important point to remember is that the lower the temperature coefficient, the better the solar panel.
Most of the time these coefficients are calculated at the laboratory temperature that is 25°C or 77°F.
How to calculate your solar panel efficiency considering the temperature coefficient.
As stated above the temperature coefficients are calculated at 25°C or 77°F, that means for every degree above 25°C or 77°F the efficiency of the solar panel will decrease by the temperature coefficient.
For example, let’s say you buy a solar panel that has a temperature coefficient of -0.3 at 25°C and an efficiency of 20%.
If you are going to install that solar panel in an area where the average temperature is 30°C, your solar panel will have an efficiency of 18.5%.
How it is calculated?
Find the difference in temperature between the laboratory temperature and the average temperature in the area of installation ( the first information is on the datasheet and the second you can even google it or find it on your local meteorological station).
In this case, is 30°C-25°C= 5°C.
Multiply the answer is the first step to the temperature coefficient.
In this case, it is 5*(-0.3)=-1.5.
Add the answer is the second step to the efficiency of the solar panel
in this case, it would be -1.5+20=18.5%.
That is a considerable drop in the solar panel efficiency, imagine if you are going to install the panel in an area with 40°C, that will impact a lot the energy production.
Those are the factors you need to consider when selecting the best solar panels for homes, now let us see what you can do to pick the best one based on the climate.
You can get this information from the datasheet, for Sunpower A-series residential solar panels you can download the datasheet here and find where it says power data, you should be able to find the efficiency and temperature coefficient
How to select the best solar panels for homes based on the climate
When it comes to selecting the best solar panels for homes, the climate plays an important role, in this case, we are going to consider two scenarios, the warm climate and in wet climate.
Shady and wet climate
If you are going to install solar panels in a shady and/or wet climate my recommendation is to go with high efficient solar panels.
The reason for this is that in this type of climate there is less solar energy so you need your solar panel to be the most efficient one.
Warm and Dry climate
If you are going to install your solar panels in a warm and dry climate, my recommendation would be to pick the solar panels with the lowest temperature coefficient and the panel with the longest warranty period.
The reason for this is that as we saw, as the temperature increases the solar panel becomes less efficient, so the lower the temperature coefficient is the better suited for the project.
Also, I will recommend considering the warranty period if you are going to install solar panels in this climate, as solar panels tend to deteriorate faster in this climate, I will recommend the warrant of at least 25 years.
Most asked questions about solar panels
Q1: How often do solar panels need to be serviced?
Solar panels do not need to be frequently serviced, if you are in an area where there is dust, you can clean them once in a while, if not the rain will do the cleaning for you.
Also, you need to make sure there are no trees near your solar panels, the shadow from the frees will decrease the efficiency of your solar panels.
Do not remove the whole tree for the environment, you can just cut the branch that is bringing shadow to the solar panels.
Q2: Can I clean solar panels myself?
Yes, you can, but solar panels have electricity that can be dangerous, so take precautions, and if you are not sure call a professional.
Q3: How to get most of my solar power?
For this, I have three tips for you.
Stay on grid
No matter how your system was sized, there are some seasons you will generate more power than you use, and there are some seasons you will generate less.
The main advantage of staying on the utility grid is that when you have an excess of electricity you can sell it to your utility company and in case the electricity produced is less than what you need you can still use the power from your utility company.
All you need to do is to have a bi-directional electric meter and it will calculate the electricity you are sending or receiving from the utility company, if you’re sending the electricity you will be getting a paycheck each month from your utility company ( that is very cool).
If you are the one who is receiving the electricity you will have to pay your utility company but this will not be the full check it will be the fraction of it ( most of your energy will be from solar panels). I have seen customers who save up to 90% of their usual electric bill.
Make sure your solar panels are clean
Dirtiness and shadows to your solar panels will decrease their efficiency to produce electricity, make sure they are clean and there is no shadow on them.
Listen to your installer
If you did not install the solar panels yourself, you need to listen to the people who did it, they have done this many times, they installed solar panels in your area, they know what works and what does not, just listen to their recommendations.
That is it, we have covered how to select the best solar panels for homes, we discussed factors you should consider in the selection process, and how to pick them depending on the climate.
If there is something we did not cover or you have further questions please leave a comment below and we will make sure we answer that question.