New operational data from a rooftop photovoltaic (PV) demonstration project in Qinghai Province, China, underscores the superior performance of LONGi’s Back Contact (BC) modules compared to traditional TOPCon technology. The findings reveal a 3.16% advantage in power generation for BC modules, further emphasizing their value in practical residential applications.
Situated in a residential complex in Xining, Qinghai, at an altitude of 2,327 meters with 2,500 annual sunshine hours and a semi-arid continental plateau climate, the test site features a fixed-tilt angle of 10°. The performance comparison was made between LONGi’s HPBC 2.0 Hi-MO 9 BC modules (11.7 kW system, 650 W/module) and conventional TOPCon modules (49.8 kW system, 610 W/module), both having identical module dimensions of 2382 x 1134 mm.
Monthly Generation Performance
Normalized data at the string level indicated that in April 2025, LONGi’s BC modules produced 288.21 kWh/kW, surpassing the TOPCon modules, which generated 279.95 kWh/kW. This results in a 2.95% monthly generation advantage for BC technology.
Source: LONGi
