Power generation performance of efficient PERC components with different bracket forms

At present, research on power generation performance of PERC (passivated emitter and rear cell) components mostly depends on theoretical calculation or short-term data measurement, and there is a lack of long-term reliable test data. Based on the Tianchang 100 MW photovoltaic power station of Huadong Engineering Corporation Limited Power China, this paper collected the power generation data of fixed-tilt (the positive-south fixed tilt, the inclination angle is 25°) PERC array B1, single axis (the north-south single-axis tracking, the inclination angle is 5°) PERC array B2, fixed-tilt polysilicon array B3 and single-axis polysilicon array B4 in 2018. The data of DC power generation of the test array inverters in 2018 were screened and processed. By analyzing the average daily power generation per watt of four arrays in 2018 and output power per watt of array B2 and array B4 on September 30 in 2018, the superior power generation performance of PERC module was verified. Then, for the further research on PERC modules (array B1 and B2), the average daily power generation per watt with the corresponding power generation gain and the daily power generation per watt in July with the highest irradiance and in December with the lowest irradiance were analyzed. The results showed that PERC component had better power generation performance than polysilicon component in the whole year whether it's single-axis tracking or fixed-tilt, with an average annual power generation gain of 5.7% and 3.7%, respectively, and PERC component maintained a high output power in case of a sudden decrease in irradiance. From March to September, the average daily power generation per watt of the single-axis PERC component was higher, with the average monthly generation gain of 13.4%, and the maximum generation gain reaching 24.9% in July. But in October to February, the fixed-tilt PERC component performed better, with an average monthly generation gain of 8.1%. In July with the highest irradiance and the largest power generation gain, the generation performance of single-axis PERC was significantly better than that of fixed-tilt PERC in sunny days. By contrast, with the lowest irradiance and the smallest power generation gain, the generation performance of fixed-tilt PERC in sunny days was significantly better in December. Because the irradiation in rainy days is mainly diffuse reflection with little tracking value, the power generation of PERC components under the two bracket forms was similar. The superior power generation performance of PERC module in the long-term operation and the power generation characteristics under different bracket forms will make it play an important role in the photovoltaic power plant. Therefore, the selection of modules and brackets in the initial stage of the photovoltaic power station construction should fully investigate the local irradiance resources and climate characteristics. If a place is rich in irradiation resources and sunny days, the single-axis PERC modules can be used preferentially under the same investment cost. The research results can provide technical support for module selection and bracket selection of the photovoltaic power station construction in future.