N-type products have obvious advantages in system end over P-Type module.

Thanks to its lower power degradation, higher bifacial ratio, lower operation temperature and better performance at low irradiance, the N-Type modules can generate 5% more power than the P-type ones at the same installed capacity.

Because the N-Type TOPCon module can improve the power generating efficiency by approximately 1% compared to the traditional PERC module, it will achieve higher installed capacity under the same installation area, saving the system BOS costs and improving the rate of return of the power station. For example, for the project in Golmud, Qinghai, China, if the price of the N-Type module is RMB 0.10/W, using the DAS Solar N-Type module can reduce the LCOE (Levelized Cost of Energy) by 2% and raise the IRR (Internal Rate of Return) of the power station by more than 0.5% compared to P-Type module.

N-Type and P-type modules of the same size can generate power of 560 W and 540 W in the front side, respectively, at irradiance of 1000 W/㎡. At the irradiance of 200 W/㎡, the performances of the N-Type and P-Type modules at low irradiance are known as 98.5% and 97%, respectively. Through calculation, we will have the front-side powers of the N-Type and P-Type modules: 560**98.5% = 110.32W, 540**97% = 104.76W. With the equation (110.32-104.76) ÷104.76×100% = 5.3%, we know that the energy gain of the N-Type module is approximately 5.3% higher than that of the P-Type module at the irradiance of 200 W/㎡.

The solar cell is a core component of the PV power-generation system. The theoretical efficiency limits of the N-type TOPCon cell and PERC cell are 28.7% and 24.5%, respectively. Under the standard test conditions: 1000 W/㎡ irradiance, cell temperature 25℃ and AM 1.5 spectrum. At the current level of industrialization, the conversion efficiency of the N-type cell reaches 24.8% and the encapsulated module has an efficiency rating of more than 22%, resulting in a module power of more than 575 watts. Thanks to conversion efficiency of 23.5% and encapsulated module efficiency greater than 21%, the P-type cell can achieve module power of approximately 550 watts. Data shows that the power of the single N-type module is 25 watts greater than that of the P-type module. In terms of power generation, the N-type module can largely improve the power-generation benefits of the PV system.

The module’s rated power is obtained under standard test conditions. Under standard conditions, the cell temperature is 25°C. However, when the module is working outdoors, the temperature of the cell module will be far more than 25°C. Under the nominal working conditions closer to actual conditions, the cell temperature can reach up to 42℃. The temperature coefficients of the N-type and P-type modules are -0.30%/℃ and -0.35%/℃, respectively. The temperature difference of cell module between nominal conditions and actual outdoor working conditions can be up to 17℃. Through calculation, the power-generation losses of the N-type and P-type modules are as follows: 17℃*0.30%/℃ = 5.1% and 17℃*0.35%/℃ = 5.95%. Thus, we know that 5.95% - 5.1% = 0.85%. Under nominal conditions, the energy gain of the N-Type module is approximately 0.85% higher than that of the P-type module.

The major differences between N-Type and P-Type monocrystalline wafers are as follows:

① They are mixed with different elements: Phosphorus for N-Type and boron for P-Type.

② Electric conduction: Electron conduction for N-Type and hole conduction for P-Type.

Structure of PERC cell: Passivation/anti-reflection film - N-Type emitter - P-Type wafer substrate - back passivation layer - anti-reflection film

Structure of the N-Type TOPCon cell: Passivation/anti-reflection film - passivation layer - P-Type emitter - N-Type wafer substrate - ultrathin tunneling layer - N-Type polysilicon thin film - anti-reflection film

Main difference between N-Type TOPCon cell and PERC cell: N-Type silicon wafer + ultrathin tunneling layer

The production line of the N-Type TOPCon cell is highly compatible with the PERC cell. Compared to the PERC cell, an additional set of equipment is provided for the production line of current mainstream TOPCon cell to manufacture ultrathin tunneling layer and N-Type polysilicon thin film. The proven N-Type TOPCon cell technology has a lower investment cost than other N-Type cell technologies.

The power-generation reliability of DAS Solar products and technologies is covered in the PV Encyclopedia. Today we'll talk about the power-attenuation warranty of the N-Type module. For N-Type and P-Type modules in the same size under identical conditions, the N Type has an attenuation rate of 1% the first year and 0.4% each subsequent year. For the P-Type module, the attenuation rate is 2% the first year and 0.45% each year thereafter. Upon calculation, in the thirtieth year, the two sides of the N-Type and P-Type modules can generate power 87.4% and 84.95%, respectively. According to further calculation results, under the same light conditions the energy gain of the N-Type module is approximately 1.73% higher than that of the P-Type module during the power-generation cycle.

The bifacial ratio is the back-side power of the module divided by the front-side power. The N-Type and P-Type modules in the same size can generate power of 560 W and 540 W power in the front side, respectively, at the same irradiance of 1000 W/㎡. For the back-side power, at the same irradiance of 300 W/m2, the calculated back-side powers of the N-type and P-type modules are 52.08 and 40.75 watts, respectively. Thus, we can obtain the back-side energy gains of the N-Type and P-Type modules, which are 9.3% and 7.5%, respectively. Please note that the final calculation results show that the back-side energy gain of the N-Type module is approximately 24% more than that of the P-Type module at the same irradiance.