N-Type vs P-Type Solar Panels: What’s the Difference
Nowadays, solar power is a leading renewable source of energy that helps us build a sustainable future. The demand for solar panels is increasing every other day. Considering the increasing demands, technological advancements to improve performance and efficiency have opened new ventures. Among modern types of solar cells, N-type and P-type solar panels have gained special attention.
Many solar buyers don't pay attention to what N-type and P-type cells are, as they are more concerned about power output, efficiency, and other similar parameters. If you are a homeowner who wants to understand these letters and choose between P-type and N type solar panels, don't miss this read, as it presents everything, from highlighting the difference between both technologies to their applications and more.
What are N-type and P-type Solar Panels?
The letters “N” and “P” show the type of semiconductor material both panels use. Simply put, N-type solar panels are made with N-type solar cells, whereas P-type solar cells combine to form P-type solar panels. Let's get into further specifics of both technologies.
- N-Type Solar Panels: In these panels, silicon is doped with elements having more valence electrons, such as arsenic (As) and phosphorus (P). As a result, the material gets free electrons in excess. Therefore, the negative charge prevails. Electrons are the majority charge carriers in N-type cells and flow from an N-type layer to a metal contact. This is how the electricity is produced. If you want to buy reliable N-type panels, try the Renogy monofacial solar panels (100W N-type solar panel, 175W N-type solar panel, and 200W N-type solar panel) or (bifacial 250W N-type solar panels and bifacial 590W N-type solar panels).
- P-Type Solar Panels: Unlike N type solar panels, P-type solar cells utilize silicon doped with elements having fewer valence electrons, typically boron (B). The doping creates positively charged holes (absence of electrons), which become the majority charge carriers. In a PN junction, the built-in electric field separates photogenerated carriers: holes accumulate in the P-type layer, while electrons move to the N-type layer. As a result, electricity is produced.
Structural Differences Between N-Type and P-Type Solar Panels
Silicon base material, performance characteristics, and charge carrier type create major differences between N-type and P-type solar panels.
N-Type Panels
They use an N-type silicon substrate with a P-type layer (e.g., boron-diffused layer in TOPCon or amorphous silicon layer in HJT) as the emitter. Anti-reflection and passivation layers are deposited on the front, with metal electrodes on both sides. Photo-generated electrons move to the negative (N-type) layer, while holes move to the positive (P-type) layer.
P-Type Panels
They use boron-doped silicon as the base, forming a P-N junction with an N-type layer (e.g., phosphorus-diffused emitter). In the external circuit, electrons flow from the negative (N-type) layer to the positive (P-type) layer.
Efficiency and Performance of N-Type vs P-Type Solar Panels
Since N-type and P-type solar panels possess different electrical and structural properties, they differ significantly in performance, durability, and efficiency. Let's dig deeper into the details.
N-Type Solar Panels
Unlike traditional P-type solar panels, N-type panels generally use solar cells with higher efficiency. If we talk about the theoretical efficiency of N-type solar cells, it reaches up to 28.7%, and the current mass production efficiency has already exceeded 25%. Renogy utilizes high-efficiency 25% N-type cells, significantly increasing the overall power output of solar panels.
P-Type Solar Panels
The conversion efficiency of these panels ranges between 18% and 23%. On the other hand, the theoretical efficiency of P-type solar cells is around 24.5%. With PERC technology nearing its theoretical efficiency limit, advancing P-type cells becomes challenging.
Comparing N-type vs P-type solar panels, you can see that N-type panels are more efficient due to several factors, including technological design advantages, bifaciality, Light-Induced Degradation (LID), temperature coefficient, and material properties.
Temperature Coefficient: Understanding Its Impact!
The temperature coefficient measures the rate at which the output of a solar panel changes with temperature fluctuations. A lower temperature coefficient means the panel can maintain higher power generation in hot environments, thereby reducing energy loss.
N-type solar panels have a lower temperature coefficient (ranging from -0.29%/°C to -0.34%/°C), which allows them to produce approximately 5-8% more energy annually than PERC panels in regions with high temperatures, such as temperate continental climates during summer or tropical deserts.
In contrast, the temperature coefficient of P-type solar panels is higher (ranging from -0.34%/°C to -0.40%/°C). It leads to a more significant performance degradation in high heat and increases long-term operation and maintenance costs.
Let's take an example to understand the effect of temperature on the power output of N-type and P-type solar panels. Suppose an N-type panel with a temperature coefficient of -0.30%/°C and a P-type panel with a temperature coefficient of -0.34%/°C, both operating at 60°C (which is 35°C above the standard test conditions of 25°C). Let's calculate the power loss for both panel types.
N-Type Panels
0.30% x 35 = 10.5% power loss
P-Type Panels
0.34% x 35 = 11.9% power loss
Result
You can see that the N-type panel loses 1.4% less power than a P-type panel in high-temperature conditions, which means it delivers 1.4% more energy output. This performance gap becomes even more significant in consistently hot environments.
Degradation and Long-Term Performance
Though both P-type and N-type solar panels experience performance degradation over time, N-type solar cells are more resistant to this process. The types of degradation panels can undergo include Light-Induced Degradation (LID), Potential-Induced Degradation (PID), Light and Elevated Temperature Induced Degradation (LeTID), and annual efficiency loss.
Generally, P-type solar panels have a first-year degradation of about 3% and an annual degradation rate of around 0.45%. In contrast, N-type solar panels experience degradation of ≤1% in the first year, followed by an annual degradation of ≤0.4%. This improvement in performance over time significantly enhances the lifetime energy yield of the solar panels. It also helps reduce the Levelized Cost of Energy (LCOE).
LID is high, and PID is moderate in P-type solar panels. Though process improvement can mitigate these degradations, the long-term performance is still affected. In contrast, PID and LID are minimal in N-type solar panels. Therefore, these panels show performance retention and long-term stability.
Moreover, N-type solar panels can often generate more electricity due to their higher bifacial factor. A more transparent rear side allows these panels to reflect more light. If we talk about the performance impact, N-type solar panels can produce up to 30% more electricity than typical monofacial solar panels. Furthermore, these panels have enhanced current transmission efficiency due to low resistance losses.
Applications of N-Type and P-Type Solar Panels
N-type and P-type solar panels have been used in a range of applications. Their unique characteristics make them suitable for different use cases. Let's explore the applications of both types of solar panels separately.
N-Type Solar Panel Applications
N-type panels are used in large-scale applications where long-term stability, maximized power output, and higher efficiency are preferred over any other parameter. In addition, high double-sided rates and higher efficiency make N-type solar panels popular for distributed photovoltaics. They can generate more power from a limited-space installation.
Moreover, these panels are the ideal choice for applications where quality and performance are preferred over the initial cost, including RVs, residential projects, and commercial installations.
P-Type Solar Panel Applications
P-type solar panels are generally heavier and larger, which makes them less lightweight and portable. However, their affordability makes them a popular choice for residential and large-scale installations, as well as off-grid systems.
Which Is the Better Option?
If you are looking for panels with higher photovoltaic conversion efficiencies, go with N-type panels. Moreover, N-type panels outperform P-type solar panels in many areas, including high-temperature conditions, high-reflection environments, and limited installation space.
Due to their lower temperature coefficient, N-type panels perform better in hot climates, resulting in reduced power loss and delivering 5-8% more energy in high-temperature regions. Therefore, if you live in hot climates and are looking for solar panels that can perform well in hot environments, install N-type solar panels
Learn more about the Renogy 250 Watt N-Type Bifacial Solar Panel here.
Similarly, the higher bifaciality of N-type solar panels enables them to generate more power in high-reflection environments, such as deserts and snowfields. Moreover, N-type panels perform better than P-type panels in space-constrained environments, such as small cabins and rooftops. They generate more power per square meter, thereby maximizing energy production from a smaller footprint.
If you are looking for panels that are less sensitive to Light-Induced Degradation, N-type panels will alleviate your concerns. When it comes to long-term stability, N type solar panels are better than their P-type counterparts. In addition, N-type solar panels have better decay resistance, a long lifetime, and exhibit greater resistance to metal impurities.
