Helping lettuce production increase by 400%! The most suitable photovoltaic module for agriculture is actually this one?

In the summer of 2025, a research team at Western University in Canada completed a groundbreaking experiment in exceptionally hot outdoor conditions—growing organic romaine lettuce under the shade of 13 different Photovoltaic Modules. The results showed that lettuce yields under cadmium telluride thin-film photovoltaic modules increased by over 400% compared to the unshaded control group, and by 200% compared to the national average yield in a typical local year!

This experiment can be said to have overturned people's traditional understanding of the relationship between "photovoltaics and agriculture"—from "photovoltaics competing with crops for land" to "photovoltaics empowering crops," and has brought cadmium telluride, a thin-film photovoltaic technology long overshadowed by crystalline silicon modules, to a wider public awareness.

Part 1: First Look at the Experiment
In the summer of 2025, London, Ontario, Canada, experienced an unusually prolonged heat wave, with 18 consecutive days exceeding 30°C. This posed a fatal threat to the growth of cool-climate romaine lettuce—high temperatures easily caused leaf wilting and premature bolting, severely impacting yield and quality. The experiment conducted by Uzal Jamil's team at Western University in Canada aims to explore the optimal integration of photovoltaic technology and agricultural production under such adverse conditions.

To ensure the scientific rigor of the experiment, the team designed a rigorous plan: the photovoltaic devices were uniformly designed with a front edge height of 2.0 meters and a rear edge height of 2.8 meters, with the modules tilted southward at a 34-degree angle to simulate an actual photovoltaic greenhouse; 13 types of photovoltaic modules (including traditional crystalline silicon and colored thin films) were selected, with a focus on testing the performance of cadmium telluride thin-film modules under different light transmittance levels; potted lettuce was planted under each Photovoltaic System, and a control group of three potted lettuce plants without shading was set up to eliminate the interference of variables. The team also used the average yield per pot of lettuce in Canada in 2022 as a benchmark—a year with mild weather and few high temperatures, a typical year for lettuce cultivation, and the data came from an agricultural census, allowing for accurate extrapolation of the technology's nationwide application.

The trial results exceeded expectations: among the 13 configurations, the cadmium telluride thin-film module performed best. The blue cadmium telluride module with 60% light transmittance increased lettuce yield by over 400% compared to the unshaded control group, and by 200% compared to the average yield in 2022!

The core value of this trial lies in demonstrating that photovoltaic modules can support crop growth through customized design. Uzal Jamil, a communications researcher, stated in a media interview that under extreme high temperatures, the shading effect of the cadmium telluride module effectively reduces field temperatures, preventing lettuce from suffering heat stress. Its customizable light transmittance and spectral characteristics can precisely match the needs of lettuce photosynthesis, achieving the dual benefits of "power generation and increased yield."

Even more exciting is that if this technology is promoted to all lettuce-growing areas in Canada, it could increase annual production by 392,000 tons, generating CAD 62.9 billion (approximately USD 46.6 billion) in economic benefits over 25 years, while reducing CO2 emissions by 6.4 million tons, effectively contributing to agricultural carbon neutrality.

Part 2: Technology Unveiled – The Irreplaceable “Agricultural Gene” of Crystalline Silicon Modules

The core reason why cadmium telluride (CdT) modules have achieved a “comeback” in agricultural scenarios lies in their “customization characteristics,” which perfectly match the needs of modern agriculture’s “differentiated planting.” Behind this lies their unique technological principles and production process advantages.

First, the light transmittance can be flexibly customized. The core contradiction in agricultural photovoltaics has always been the balance between “photovoltaic power generation” and “crop lighting”—photovoltaic modules need to block sunlight to generate electricity, while crops need sunlight for photosynthesis; the two seem contradictory. As a core type of thin-film photovoltaics, CdT modules can adjust the light transmittance between 20% and 80% according to the different light requirements of crops, satisfying the basic needs of photovoltaic power generation while providing suitable lighting conditions for crops.

Secondly, cadmium telluride (CdT) modules offer strong spectral adaptability, enabling targeted promotion of crop growth. By adjusting the formulation and thickness of the thin-film material, CdT modules can achieve customized spectral filtering, retaining the beneficial spectrum for crop growth while filtering harmful ultraviolet and infrared rays. This promotes crop growth and reduces pests and diseases.

Thirdly, they exhibit outstanding low-light power generation performance, adapting well to the complex lighting environments in agriculture. Compared to crystalline silicon modules, CdT modules demonstrate higher power generation efficiency and less degradation under low irradiance conditions (below 200 W/m²). This means that even in cloudy weather, during dawn or dusk, or when sunlight is insufficient, CdT photovoltaic systems can generate stable power to meet the electricity needs of greenhouse irrigation, supplemental lighting, and temperature control equipment.

Notably, CdT modules also exhibit higher oblique light capture efficiency, meaning that during the lower angle of the sun and at dusk, they can absorb more light for power generation. Moreover, this characteristic is better suited to the electricity price curve after my country's power market reform—morning and evening are peak electricity price periods, and the high-efficiency power generation capacity of cadmium telluride modules during these times can significantly improve farmers' electricity generation income.

Furthermore, cadmium telluride modules offer flexible installation, strong resistance to extreme weather, and adaptability to various terrains, reducing soil evaporation rates.

Part 3: Cost Reversal—Less than 1% of Production Capacity, How Can It Catch Up with Crystalline Silicon Modules?

For a long time, thin-film photovoltaic technology suffered from significantly higher production costs than crystalline silicon modules due to small production scale, reliance on imported core equipment, and complex production processes, hindering large-scale adoption. Cadmium telluride modules, as the mainstream type of thin-film photovoltaics, were no exception. However, with leading domestic companies achieving breakthroughs in core technologies and localizing equipment production, this situation is gradually changing.

In recent years, domestic companies have made continuous efforts in cadmium telluride thin-film solar cell technology, constantly breaking through efficiency bottlenecks: Longyan Energy's highest laboratory photoelectric conversion efficiency has reached 20.7%, and the efficiency of its mass-produced modules has exceeded 17.4%, with plans to increase the mass-produced efficiency to 20% within the next three years, gradually narrowing the efficiency gap with crystalline silicon modules; Kaifeng Chenya New Energy has overcome the technical difficulties of vacuum transport deposition, controlling the coating uniformity within 3% and achieving a cadmium telluride utilization rate of over 90%, further reducing material loss and production costs through technological optimization.

Although the laboratory efficiency of cadmium telluride modules is still slightly lower than that of crystalline silicon modules, as demonstrated in the previous experiments, its overall power generation performance is actually more advantageous in agricultural applications.

At the same time, the localization and automation of equipment have also provided solid support for cost reduction in cadmium telluride modules. Previously, the core production equipment for cadmium telluride modules relied entirely on imports, resulting in high equipment procurement costs and inconvenient maintenance and upgrades, directly driving up module production costs. In recent years, domestic enterprises have actively promoted the localization of core equipment, with leading companies achieving 100% localization rates for equipment and raw materials. Fully automated production lines have also significantly improved production efficiency and reduced labor and equipment costs.

Furthermore, larger sizes have further reduced the unit cost of cadmium telluride (CdT) modules. Older generation CdT modules were mostly 1200×600mm, while the new generation of ultra-large modules has jumped to 1215mm×2300mm, increasing the single-cell area by approximately 2.3 times. Single-line annual production capacity reaches 2.9 million square meters. The increase in panel area and single-cell power directly reduces the unit manufacturing cost.

Finally, it's worth mentioning that compared to the "long industrial chain" of crystalline silicon modules, the CdT module production line is only slightly over 1000 meters long. It can realize a complete production process from photovoltaic glass edge grinding and cleaning, compound semiconductor thin film preparation, to module packaging and testing. This highly integrated production model avoids the cost accumulation caused by multiple links in the supply chain.

Part 4: Diverse Value, Beyond Agriculture

In fact, the value of cadmium telluride (CdT) modules extends far beyond agricultural photovoltaics.

With its core advantages such as excellent low-light performance, low temperature coefficient, uniform and aesthetically pleasing appearance, and customizable light transmittance, it is breaking down the boundaries of traditional distributed Power Stations, extending from agricultural scenarios to broader fields such as architecture and transportation, becoming an ideal choice for Building Integrated Photovoltaics (BIPV) and various "PV+" models.

On building roofs, CdT photovoltaic tiles can directly replace traditional roof tiles. Their highly customizable nature allows them to naturally fit various architectural styles. Compared to traditional Photovoltaic Panels, their superior anti-shading performance can adapt to complex roof structures and localized shading environments, effectively avoiding power generation losses and system failures caused by shadows.

Furthermore, it supports personalized customization such as colors and company logos, breaking away from the monotonous layout of traditional photovoltaic arrays and achieving seamless integration with building roofs. The roof of XPeng's new global headquarters building uses CdT modules to form an "X" shape, becoming a model of building-photovoltaic integration.

On building facades, cadmium telluride (CTD) modules can also be used as curtain wall glass, skylights, and residential sunrooms. By precisely adjusting light transmittance, they can balance indoor natural lighting and power generation needs. These BIPV applications not only significantly improve building energy efficiency, but their technologically advanced and customized appearance also gives buildings a unique green identity, becoming a shining example of low-carbon city construction.

In the transportation sector, in "photovoltaic-storage-charging integrated" parking lots/charging stations, CTD BIPV carports combine parking space with power generation facilities. The generated green electricity is prioritized for supplying charging piles within the parking lot, achieving a closed loop for new energy vehicles to use "new energy electricity."

There is also a less common application: automotive sunroofs. CTD sunroofs transform the car roof into an "invisible generator," powering auxiliary systems such as air conditioning and small refrigerators, reducing the burden on the battery.

Furthermore, along highways and elevated roads, cadmium telluride double-sided photovoltaic glass is integrated into sound barriers, transforming them into rows of "vertical power stations" while fulfilling their noise reduction and environmental protection responsibilities. In Hangzhou, after installing such photovoltaic sound barriers on an elevated road, sound insulation improved by 5-6 decibels, achieving both environmental governance and transforming a one-time investment in environmental facilities into assets that sustainably generate green electricity.

From the "yield increase miracle" in agriculture to the "surface revolution" in the construction sector, and then to the "green innovation" in transportation, cadmium telluride thin-film photovoltaic modules, with their unique technological advantages and continuously optimized cost control, have broken the monopoly of crystalline silicon modules in the photovoltaic market, forging a differentiated development path.

In the future, with continued cost breakthroughs, expanding production capacity, and the deepening of the "photovoltaic+" model in various fields, the once "niche" cadmium telluride modules may gradually enter the mainstream market, unlocking green possibilities in more scenarios!