Types of Solar Panel: Which Is Your First Choice?

Solar panels are devices that capture sunlight and convert it into electricity. They are usually mounted on roofs and can power everything from small appliances to entire homes. Solar panels come in a variety of shapes, sizes, and types, so it's essential to do your research before making your purchase. In this article, we'll break down the different types of solar panels so that you can make an informed decision about which one is right for you.

Why Solar?

Most homes have easy access to electricity from the grid. So why worry about solar panels? In October 2020, the International Energy Agency released a statement that solar energy was the most cost-effective source of electricity. You can take advantage of that and produce your own energy on your rooftop. No longer does it matter whether you want to make an environmental choice; it’s more so about saving money on your electricity bill.

There is also another advantage: Having your own supply of energy makes you less dependent on the energy grid. With energy use predicted to increase in the coming decades, many experts say that the reliability of the existing power grid will decrease. More brownouts and blackouts will be the rule. Having solar panels makes you independent and less vulnerable.

What are Solar Panels and How do They Work?

The process of converting sunlight into electricity is called the photovoltaic effect. Solar panels are made up of many individual solar cells, and each solar cell is able to convert a small amount of sunlight into electricity. When multiple solar cells are combined, they can create enough power to run electrical devices like a refrigerator, a washing machine, or even entire homes.

types of solar panel - Growatt

Solar Panel Size and Power

There are two main sizes for residential solar panels; the larger size 72-cell panels (approx. 3.25 x 5.5 feet) and the smaller size 60-cell panels (approx. 3.25 x 6.4 feet). While larger panels are often more economical, they tend to be harder to fit if the space for installation is tight.

In order to determine how powerful a panel is, look at its declared output, aka wattage. A higher number of watts (W) signifies a higher capacity to produce energy. You will find significant differences between panels. Some will be able to produce, e.g. 350W, and another type of panel will be rated at 385W. Higher wattage on the same size of the solar panel indicates a higher efficiency product that will be able to produce more electricity on the same surface. Where space is limited, panel efficiency becomes a relevant factor when choosing the panels for installation at your home.

Solar Panel Materials

At the heart of each solar panel are the solar cells, which are usually made out of silicon. It is the most common semiconductor material used in solar cells, representing approximately 95% of all modules sold today. It's also second only to oxygen as an abundance on Earth and is well known for its use in computer chips. Crystalline silicon cells are made up of atoms connected, forming a lattice that efficiently converts light into electricity. Silicon is an extremely durable material, which in turn has led to an expected lifespan for solar panels of between 30-40 years.

Other Materials Used in Solar Modules

Most residential solar panels will come with frames that are made from aluminum. The metal has unique qualities that make it ideal for use on solar modules. Aluminum is highly durable even when exposed to the elements, providing for the panel’s longevity. It is also lightweight, sturdy, and flexible, enabling easy handling and installation, and great for bearing heavy loads.

The solar cells are encased by layers of glass, protecting them from the elements while ensuring sunlight can reach them. There is, of course, the need for transparency, and glass also checks the durability box; that’s why it has found industry-wide application in the manufacturing of solar panels.

Types of Solar Panels

There are three main types of solar panels: monocrystalline, polycrystalline, and others such as thin-film. Monocrystalline solar panels are made from a single crystal of silicon and generally are more efficient than other types of solar panels. They are also more expensive. Polycrystalline solar panels are made from multiple silicon crystals and are less efficient than monocrystalline solar panels. However, they are also less costly.

Thin-film solar panels are made from a thin layer of semiconductor material deposited on a substrate. They are the least efficient type of solar panel but also the most flexible, making them ideal for use in various smaller applications.

Monocrystalline Solar Panels - The Most Prevalent

Monocrystalline solar panels are an excellent choice for those who want their electricity to be clean and renewable. They are the most commonly used residential solar panel to date because they have high power capacity and efficiency. Monos can reach 20%+ efficiencies, making them THE most efficient panel on today's market!

The high-quality silicon cells generate more power than other types, and a higher wattage panel means more energy per square foot on your roof! So, if space is tight, you will often land with this type of panel. Also, Monos can blend right into any dark color shingle. Their black color gives them a modern appeal, consistent with the design of many modern homes. Why are they black? A dark surface absorbs light better than lighter colors, especially in low-light conditions.

The prices of Monos tend to be higher. This is mainly a result of the more intensive production process.

Monocrystalline Solar Panels - Growatt

Polycrystalline Solar Panels - A Cheaper Option

Polycrystalline solar panels are made from multiple crystals of silicon. Instead of using a single crystal, manufacturers melt the silicon pieces together to form solar cells.

Polycrystalline solar panels are the less expensive option, but they have lower efficiencies than Monos. Their efficiency is usually around 15-18%. Generally, each panel contains more crystals, limiting the room for electrons to move around. This results in lower energy production per square inch of surface area. This means you will need more space or taller modules to produce the same amount of electricity if considering this technology. Polys have a blue hue as compared to the black of the Monos.

What are Thin Film Solar Panels?

Thin film solar panels are often less efficient than monocrystalline or polycrystalline. While efficiencies can vary based on which materials are used in the cells, they usually lean more toward an efficiency rating of around 7% and up to 18%. If you want to produce equal amounts of electricity with your system, you need comparably more panels. They are also less durable than Monos or polys, making them an unlikely choice for a rooftop panel.

Thin film solar panels are more recent, but they've already captured an impressive market share. They're made with cells with light-absorbing layers 350 times smaller than average silicon ones, making them a very flexible energy source; they come in many different sizes, shapes, and colors.

Monocrystalline vs. Polycrystalline - Pros and Cons

Monocrystalline and polycrystalline solar panels both have their benefits and drawbacks. Monocrystalline panels are more expensive to produce but are also more efficient and take up less space. Polycrystalline panels are less costly but are not as efficient and take up more space. When deciding which type of solar panel is right for you, consider your budget, the size of your property, and how much sun exposure you get.

Solar Panel Applications

Many fantastic, innovative products are based on solar cell technology. For example, charge your phone with booklet-size fold-up panels while away on a camping trip. Or how about a portable power station?

Another great application is the solar generator, such as the Growatt 2000W solar generator. Not solely dependent on solar, it can be hooked up to a car or an electrical outlet. It includes a battery, making it an extremely versatile powering device. It has extendable 200W monocrystalline solar panels, making it the environmental alternative to a gas-powered generator.

How to Choose the Right Type of Solar Panels for Your Needs

Monocrystalline solar panels are usually darker in color, while polycrystalline solar panels are typically bluer. If you are limited by the amount of space available on your roof, then investing in more efficient monocrystalline solar panels is preferable. However, if you have a lot of roof space or are installing ground-mounted solar, then polycrystalline panels may be more economical.

When you have plenty of space available, the lower price of polycrystalline panels is not a problem. However, installing more panels is not an option when you have limited space, so monocrystalline panels will maximize electricity production in the available area.

Monocrystalline vs Polycrystalline - Growatt

How Long will Solar Panels Last?

The product’s lifespan is usually not affected by which type of silicon structure was used in the production; both polys and Monos generally have excellent lifespans that can reach up to 40 years for high-quality panels. A good indicator of a panel’s quality is the warranty. 25-year warranties have become commonplace, with some manufacturers offering 30 years of coverage.

Although solar panels are designed to have a long lifespan, the loss of production capacity over time is inevitable. Most often, panels lose about 0.5% of their productivity each year. But that is more of an average number. It is worth looking up the so-called degradation rate of your panel to get a better idea of the expected productivity down the road.

The most important thing is to choose a high-quality panel that will continue producing electricity at an acceptable level for many years. There are several ways to ensure you get a good quality panel, such as looking for certifications, reviews, and warranties. With proper care and maintenance, your solar panels should last for decades, providing you with clean, renewable energy.

About Solar Panel Efficiency

Solar panel efficiency measures how much power a solar panel can produce relative to its size. The higher the efficiency, the more power a panel can produce in a given area. However, Solar panels with high efficiency typically come at a higher price tag. You will have to decide whether the increased cost is worth it for your needs. Another consideration is that panels with high efficiency take up less space, so if you have limited room, going with a lower-efficiency panel may not be an option. Of course, there are other factors that affect the efficiency of solar panels, see how to improve the efficiency of solar panels.

The bottom line is that each panel comes with a wattage rating, which is measured using an industry-standard called STC (Standard Test Conditions). Most recently, 60-cell panels range from about 340 – 390 W, while the larger 72-cell panels range from about 410 – 480 W. The more efficient a panel is, the higher its wattage rating will be.

The Temperature Coefficient Explained

Monocrystalline solar panels are often seen as the best type of solar panel. They are more efficient and have a longer lifespan than polycrystalline solar panels. However, polycrystalline solar panels may be a viable option if you live in a cooler climate. Why?

Solar panels are affected by temperature. They heat up and lose some of their productive capacity. The temperature coefficient measures this effect. In general, the temperature coefficient of polys is higher than that of Monos, which means they heat up more quickly and lose productivity. This is especially true in hot climates. When you live in a moderate or cold climate, the coefficient is less of a concern for the panel’s performance.

Technology keeps improving, though, with more solar panels of both types with similarly low-temperature coefficients hitting the market.

Conclusion

Solar panels come in two main types: polycrystalline and monocrystalline. Polycrystalline panels are less expensive, but monocrystalline panels are more efficient and have a longer lifespan. You will need to decide which type of panel fits your needs and budget. Another thing to consider is the temperature coefficient, which affects how well a solar panel performs in different climates. Technology keeps improving, so it's worth checking out the latest options on the market before making your decision.

Panel type

Polycrystalline

Monocrystalline

Efficiency

Less efficient

More efficient

Lifespan

25 years plus

30 years plus

Cost

Lower cost

Higher cost

Look

Blue

Black

Temp. coefficient

Higher

Lower