Why does HJT have a clear advantage in BIPV applications?

Today, as photovoltaic technology and architecture become increasingly integrated, building-integrated photovoltaics (BIPV) have emerged as a key driver of green‑building development. BIPV demands that photovoltaic modules serve not only as power‑generating units but also as architectural materials—balancing high‑efficiency energy conversion with the complex requirements of safety, aesthetics, durability, and design integration. In this interdisciplinary field, heterojunction (HJT) cell technology, owing to its distinctive technical attributes, is attracting widespread attention from both industry and academia and is regarded as a highly promising technological pathway.

The core value of HJT lies in its superior high-temperature power-generation efficiency and stability, significant bifacial power‑generation gains, and strong compatibility with a sleek all‑black aesthetic—precisely addressing the three major pain points hindering the widespread adoption of BIPV.

I. High-Temperature Scenarios: Efficiency and Stability Are Key

BIPV rooftops are exposed to high-temperature conditions year-round—often exceeding 40°C in southern regions during summer. Conventional PERC crystalline silicon modules typically exhibit a temperature coefficient of –0.38% to –0.42% per °C; under extreme heat (e.g., 58°C, a 33°C deviation from the standard test condition of 25°C), their power‑generation efficiency can decline by more than 15%. Even in typical summer heat (around 40°C, a 15°C difference), losses amount to approximately 6.75% to 6.3%. In contrast, HJT modules, with an ultra‑low temperature coefficient of –0.20% to –0.25% per °C, experience only 3% to 3.75% efficiency loss under similar high‑temperature conditions, and even under extreme heat, losses remain capped at around 8%. Field measurements confirm that, in southern regions where high temperatures are frequent, HJT‑based BIPV systems deliver 8% to 12% higher annual energy yields compared to conventional crystalline silicon solutions, demonstrating a clear performance advantage.

II. Dual-Sided Power Generation: Architectural Reflections Become a “New Resource”

The core principle of BIPV is to harness the building’s inherent characteristics for power generation, rather than simply adding photovoltaic panels as an afterthought. HJT modules, with no aluminum back‑field shading on the rear side and a transparent conductive oxide (TCO) design, typically achieve a bifaciality factor exceeding 90%—compared to the industry average of 70%–80% for PERC modules—enabling highly efficient capture of reflected light from rooftops. In applications such as white color‑steel‑tile roofs, sunrooms, and skylights, bifacial power generation gains can reach 10%–20%; however, on dark, low‑reflectance roofs, these gains drop to around 5%. Overall, the optimal performance must be assessed in conjunction with the specific characteristics of the building’s surface.

III. Aesthetic Integration: Pure Black Equals Sophistication, with Zero Visual Distraction

One of the biggest hurdles to the widespread adoption of BIPV is the visual clash between photovoltaic modules and architectural aesthetics. HJT modules, with their naturally deep black appearance, high surface uniformity, and fine‑grid design, deliver a visual finish that closely resembles architectural glass, offering a level of simplicity far superior to conventional blue crystalline silicon panels. Although there is currently no unified industry testing standard, in subjective evaluations for curtain‑wall applications, HJT modules demonstrate markedly better grid visibility and color consistency, significantly reducing visual clutter compared to traditional crystalline silicon panels and making them well suited to the demands of high‑end architectural design.

Why is HJT another preferred pathway for BIPV?

Overall, HJT is, in theory, a technological solution well-suited for BIPV applications.

• Low temperature coefficient → Well-suited to the high-temperature conditions of building rooftops, delivering superior efficiency and stability;

• High bifaciality → Enables capture of reflected light from buildings, enhancing power generation efficiency in suitable applications;

• Pure black fine grid lines → High visual integration, perfectly aligning with the aesthetic demands of high-end architecture;

• Economic efficiency → Compared with other thin-film photovoltaic products, HJT offers higher power generation and lower costs.

Overall, in BIPV applications, HJT’s advantages are certainly noteworthy; however, the specific implementation should be determined through a comprehensive assessment that takes into account the project budget, site-specific requirements, and aesthetic considerations.

Industry Insights

At present, HJT‑BIPV is riding a wave of industry momentum. Looking ahead, as the “four‑busbar” encapsulation technology—designed to reduce shading losses and enhance resistance to microcracking and safety—becomes more widespread, and as cost‑reduction efforts across the HJT value chain accelerate, HJT’s share of BIPV applications will continue to grow. It will complement other technological pathways such as TOPCon and flexible perovskite, jointly driving the advancement of building‑integrated photovoltaics.