What you should know to choose solar panels that best suit your needs. If you ask us “ what is the best photovoltaic solar panel for me? ” , without more information, the answer may not be as conclusive as you hoped. And this is because when making a long-term investment such as solar panels, you have multiple options that will depend on factors such as how much energy you need and how much space you have to install your photovoltaic self-consumption .
How to choose the best solar panels
A standard panel, for example, can work just as well as an expensive, high-efficiency panel in certain circumstances. The same thing happens with size; a large panel does not have to always be the best option. You should also pay attention to the characteristics of the equipment (efficiency, power, aesthetics, etc.) and the price, especially if you have a tight budget.
At Cambio Energético we want to contribute so that more families and companies can enjoy the savings that consuming your own clean energy means. That is why we always advise you to inform yourself and ask all the doubts you have . Our team of technicians and engineers will always be ready to resolve any issues that may arise so that you can choose the solar panels that best suit your needs.
In this article we present the key elements that you must take into account when you want to choose the solar panel that you need for your self-consumption installation.
What should I know before choosing solar panels?
There are a couple of things that you will need to know before you start looking for the solar panels that are best for you: the consumption and power that you need, and the characteristics and the space that you have for your installation.
Electrical consumption and contracted power
To find out your annual electricity consumption, you can consult one of your electricity bills.
In the example shown below, in the “Electricity consumption information” section, you will find the last month’s consumption on the left and the graph with the monthly consumption on the right. If you want to know the annual consumption, you can see it below the graph, along with the average daily consumption in the last month and in the last 14 months.
If you have a smart meter, you can register on the digital platform of your marketer and check your consumption directly from there.
Below the electricity consumption information you have another section in which the “Contract data” will appear, where you can check the power you have contracted ; which indicates the number of kWh you can consume simultaneously. This will be very useful when it comes to seeing the power you need in your installation.
Detail of the contracted power in the electricity bill
Space available for solar panels
To calculate the space you have for the photovoltaic installation , you have to take into account not only the meters you have but also the possible obstacles, whether physical (windows, chimneys, air conditioning systems, antennas, etc.) or in form of shadows that can affect the solar panels such as those that can be produced by trees, adjoining buildings, etc…
And why is it important to know the available space? Very easy, because the number of solar panels you can install will depend on it. And this, in turn, will determine the type of solar panel that best suits you. For example, if you have enough space, you may be interested in installing solar panels with less efficiency , which are cheaper at the same time, so you can put a higher number. However, if you have limited space, you may be interested in more efficient solar panels , which produce more energy per square meter, even if they have a higher price.
The type of roof, the inclination and orientation of the same can also influence the number of plates that you need, and if your roof does not have an optimal inclination or orientation, it will be necessary to assess whether or not it is worth putting tilting structures. for solar panels so that they have maximum performance, or if, on the contrary, the loss of performance due to any of these characteristics should be compensated by increasing the installation surface of the panels.
In these more particular cases, our recommendation is that you consult with expert installers who can explain the pros and cons of both options. We at Cambio Energético always explain to customers the different options they may have and why we recommend one or the other based on of the given features.
Taking this information into account, it would now be time to review the characteristics of the solar panel itself.
What features of solar panels should I pay attention to?
Solar panels have a series of characteristics that we must pay attention to in order to know which model suits you. Let’s see the features that can guide you.
Efficiency of solar panels
Solar panel efficiency is the percentage of sunlight that the panel receives and is converted into electrical energy . Currently, we can distinguish between:
- Standard Efficiency Panels . They include most current solar panels and have an efficiency of between 17% and 18%.
- High efficiency panels . Its efficiency can range between 19% and 23%.
The more efficient it is, the more it will produce but also the more expensive it will be. Therefore, you should know that the greatest efficiency is not always the best option, as we explain in this blog post .
And directly related to efficiency, you have the temperature coefficient , that is, the impact of heat on the performance of the solar panel. And high temperatures are not good friends with your solar panels , as they will reduce their performance and affect the conservation of the equipment. The lower this coefficient, the better it will respond to heat.
Solar panel peak power
Peak power (measured in Wp) is the maximum energy that your photovoltaic solar panels can produce at a given time under certain standard conditions (temperature: 25ºC; received irradiance: 1000 W/m²; air mass: 1.5).
You can find solar panels with powers from 50 Wp to more than 500 Wp . The higher the wattage of a panel, the more electricity it can potentially produce for your home or business. But just like efficiency, generally the more power you have, the higher your price .
Also, the higher its power, the larger the solar panel will be . This can mean that fewer panels will fit in a given space, thus nullifying the advantage of having more power by installing more solar panels. In this blog entry we explain it to you with a practical case .
Types of solar cells used
There are different types of solar panels that use different types of solar cells. . We can differentiate between monocrystalline, polycrystalline and amorphous or thin-film silicon cells.
Monocrystalline silicon offers high efficiency and good heat tolerance characteristics. Solar panels based on polycrystalline (or multicrystalline) silicon cells are now the most popular choice in residential installations. They have less efficiency than monocrystalline, but are also cheaper. Amorphous (or thin-film) silicon cells use less silicon and allow the panels to be more flexible and lighter, and therefore easier to install. However, its efficiency is the lowest, as well as its useful life.
|monocrystalline||– High efficiency||– Higher cost|
|polycrystalline||– Lower cost||– Lower efficiency|
|thin film||– Flexible and light||– Very low efficiency – Short life expectancy|
The visual appearance of solar panels is something that can generate different opinions. In recent years, solar panel manufacturers have come a long way in improving the aesthetic appeal of a facility.
There are a number of all-black solar panels that are popular due to their sleeker appearance. However, there is a price to pay for the improved aesthetics and if you don’t mind silver busbars (lines) on the panels, opt for a black frame with a white backing sheet. instead of an all-black panel may provide a reduction. of the initial investment.
Another consideration with an all-black panel other than cost is the marginal decrease in efficiency . As we said, solar panels are more efficient at lower temperatures, so by having a black backing sheet, the panel absorbs more heat, heating up the plate and decreasing efficiency by about 3% . It’s also worth noting that the highest power panels on the market are not completely black, so there is often a need for a compromise between aesthetics, cost and efficiency.
What other things should I take into account to choose my solar panels?
In addition to knowing your energy needs, the space on your roof and the characteristics of the solar panels, it is important to look at other elements such as the guarantee, the manufacturing company and, of course, the price of the product.
The guarantee is a fundamental element since we are talking about components built to last more than 25 years with minimal maintenance. Hence, the longer the guarantee, the better.
The duration of the guarantee is a message from the manufacturer of the solar panel in which they show their confidence in the product . Generally, the longer the warranty, the higher the quality of the panel.
Solar panel manufacturers offer two types of warranties :
- Product warranty: it is the one that covers factory defects that the solar panels may have. In standard efficiency solar panels, this warranty is usually between 10 and 12 years. While in the highest efficiency plates this guarantee is usually extended to 25 years.
- Production guarantee: it is the one that assures you the percentage of performance at which they will work throughout the established time, generally between 20 and 25 years. In the standard plates they can guarantee that your plates will yield 90% in the first 10 years and 80% up to 20 years. High-efficiency panels can guarantee that your solar panels will produce around 90% for up to 25 years.
Although we talk about the guaranteed duration, you should know that solar panels usually last longer thanks to the inherent durability of the product. Because there are no moving parts in the panels, they can keep generating power until the solar cells run out of conductive material completely.
In addition to the guarantee it offers, it is also important to look at the manufacturer itself . . Why? Because it is of little use to us to have a guarantee of 12 or 25 years, if when we need to make use of it, the company no longer exists.
With the boom in photovoltaic energy, many new companies have emerged to try to gain a foothold in the photovoltaic market. But not all these projects have the necessary experience or are consolidated to last the time of the guarantee. For this reason, betting on brands such as SunPower, Canadian Solar, Hyundai or Sharp , among others, with a long history and proven experience, can give you the peace of mind that they will be there when you need them.
Last but not least, the price. This will be determined by variables such as: efficiency; the power; the brand; the quality of the materials; the guarantee; and the certifications that the solar panel may have.
But to make your task easier, let’s say we can classify manufacturers and their panels into three types :
- Economic option: they are the cheapest but with a quality that is not up to other well-known brands. They are the typical options that you find general or non-specialized online sellers. These companies often do not have a strong online presence and it can be difficult to find useful information about their products. So better discard this option.
- Standard option: they are the best known and most widespread brands, . They offer efficiency, cost effectiveness, decent warranties, and competitive prices, while being durable and performing very well in almost all situations.
- Premium option : high quality and high cost. They offer higher efficiency and production, longer warranties and stronger components. But its price is significantly higher: double or more than standard panels!
Do I need to buy the most expensive solar panels?
The answer would be, it depends. Do you have enough space on your roof? Do you have shadows that you will not be able to avoid? If you do not have a lack of space, the most interesting thing is to install standard plates , since they are cheaper and, therefore, you will be able to install a greater number and enjoy greater production.
But if you have space limitations or need to get the maximum power from your roof, you may be interested in going for premium panels , since you will get more production per square meter.
Now you have the tools to guide you when choosing the solar panels that best suit your needs. However, from Cambio Energético we recommend that you inform yourself well (in this blog you will find many entries on solar panels) and that if you have any questions, ask or request a quote.
If you are thinking of installing a self-consumption, in Cambio Energético we always carry out a preliminary study of the needs of our clients in order to guide them on what type of solutions are best suited to the purpose of their installation.