The pace of PV cell technology iteration is accelerating: n-type TOPCon has become the dominant choice for new capacity, HJT (heterojunction) production is expanding steadily, and pilot lines for perovskite/crystalline-silicon tandems are coming online one after another. Behind every new efficiency record lies a fresh set of challenges for PV testing.

Higher Parameters Test Measurement Ranges

The open-circuit voltage and power of new high-efficiency modules keep climbing, and larger formats compound the demands on the voltage/current ranges and sampling speed of test equipment. With 1500 V now standard for utility-scale plants, instruments need sufficient headroom and faster transient response to faithfully reproduce the I-V characteristics of high-power modules.

Bifacial Generation Changes Test Methods

Both TOPCon and HJT are bifacial technologies, with bifaciality factors reaching 80% and beyond. Measuring bifacial module performance in accordance with IEC 60904-1-2 — and properly accounting for rear-side gain in field tests — has become a shared concern for laboratories and O&M teams alike.

New Failure Modes Call for New Detection Methods

• Micro-cracks and broken fingers: thinner wafers make cells more fragile, so EL inspection demands higher resolution and lower dark-current noise;
• PID and LeTID: potential-induced and light-and-elevated-temperature-induced degradation show new signatures in n-type cells, requiring combined electrical and imaging analysis;
• Perovskite stability: tandem cells are sensitive to light, temperature and humidity, demanding tighter environmental control and data logging during testing.

Digitalization Is the Common Direction

However cell technology evolves, the digitalization and cloud integration of test data is a certainty. Connecting test instruments to plant asset management platforms turns every field measurement into a retrievable, comparable historical curve — the data foundation for lifecycle plant management.

"Cell technology changes; the mission of testing does not — measuring the true performance of every watt with trustworthy data," commented Longlight Energy's R&D Director. "Our next-generation products will keep evolving around wider ranges, AI imaging analysis and cloud collaboration, in step with the industry's technology rhythm."