Solar Panel Manufacturing: Materials, Technology and Sustainability

The global demand for solar panels has been steadily rising year after year as renewable energy sources gain prominence in the quest for sustainable power generation. This article provides an in-depth exploration of the solar panel manufacturing process, encompassing the materials and technology employed, the pursuit of efficiency and performance, stringent quality control and testing procedures, and the vital sustainability aspects associated with solar panel production.

Global Demand and Supply of Solar Panels 

Around 12% of global electricity supplies came from wind and solar power in 2022, rising to 39 percent when combined with other renewables and nuclear. In 2022, solar added a record of 245 TWh of generation in 2022, while wind added a record 312 TWh – together accounting for 80 percent of the world’s increased need for electricity that year. 

The Graph shows the total manufacturing capacity for Solar panels by region and the demand for certain components that are used for manufacturing solar panels for 2021, China is leading the chart in every aspect followed by APAC (Asia and Pacific) and Europe. China’s share in all the manufacturing stages of solar panels exceeds 80%, this is more than double China’s share of global PV demand. The total value of global PV-related trade – including polysilicon, wafers, cells, and modules – exceed USD 40 billion in 2021, an increase of over 70% from 2020.

Solar Panel Components

A solar panel is a complex device comprised of several critical components, each playing an indispensable role in its functionality, resilience, and effectiveness. Understanding these components is crucial to appreciating the intricate process of solar panel manufacturing:

1. Solar Cells: These are the heart of a solar panel, responsible for converting sunlight into electricity through the photovoltaic effect. Solar cells can be categorized into various types, including monocrystalline, polycrystalline, and thin film, each with its unique advantages and manufacturing methods.
2. EVA Film: Ethylene-vinyl acetate (EVA) film serves as a protective encapsulant for the solar cells. It shields them from external environmental factors, such as moisture, dust, and temperature fluctuations, while allowing light to penetrate.
3. Polymer Backsheet: The polymer backsheet is positioned on the rear side of the solar panel, acting as an additional protective layer. It ensures the longevity and durability of the panel by guarding against moisture ingress and mechanical damage.
4. Toughened Glass: Positioned as the front cover of the solar panel, toughened glass not only safeguards the delicate solar cells but also permits the passage of sunlight. Its optical properties are crucial for optimizing energy absorption.
5. Aluminium Frame: The aluminium frame serves a dual purpose – it provides structural support to the panel and facilitates ease of installation. Ensuring the frame’s integrity is essential for the panel’s long-term performance.
6. Junction Box & Connectors: The junction box serves as the electrical interface between the solar panel and external systems, including wiring and inverters. It houses diodes and connectors that enable the efficient transfer of generated electricity.
7. Silicone Sealant: Silicone sealant plays a critical role in maintaining the panel’s integrity. It is used to create a watertight seal between the various components, preventing moisture ingress and potential damage.
8. Copper Ribbon: Copper ribbon is employed to interconnect individual solar cells within the panel. Ensuring reliable connections is essential for maximizing energy output.
9. Packaging Material: The final packaging material is employed for safe transportation and storage, protecting the panels from potential damage during transit.

Solar Panel Manufacturing Process:

The manufacturing of solar panels is a meticulously orchestrated process that seamlessly blends automation with manual craftsmanship to meet the exacting standards of performance, quality, and reliability. Below is a comprehensive breakdown of the key manufacturing steps involved:

• Cell Stringing: Solar cells are placed on a conveyor belt, connected, and cut to form strings with precise electrical configurations.

• Lamination: Panels undergo an EL test and are then laminated with toughened glass and EVA film for durability and weather resistance.

• Trimming & Inspection: Panels are trimmed to uniform dimensions and visually inspected for quality.

• Frame Integration: Metal frames are custom-built, aligned, and securely attached to panels.

• Junction Box Installation: Junction boxes are added to the panels’ backs for a weatherproof connection.

• Cleaning: Panels are cleaned to remove production residues.

• Testing: Rigorous tests ensure panels meet safety and performance standards, with reports provided for reference.

Sustainability and Environmental Impact:

While solar panels are celebrated as a green energy solution, it is important to acknowledge that their manufacturing process does carry environmental implications. Addressing sustainability aspects is crucial for mitigating the environmental footprint associated with solar panel production:

1. Mining for Materials: Extraction of silicon, metals like silver and copper, and other materials can generate emissions and pollution, emphasizing the need for sustainable mining practices.
2. Facility Impact: Solar panel manufacturing facilities may disrupt habitats, rely on energy from polluting sources, stress water resources, and require strict pollution control measures.
3. Manufacturing Process: Different panel types have varying carbon footprints, driving the industry to reduce energy consumption and emissions during production.
4. Transportation: Global production and transportation of panels contribute to significant carbon emissions, prompting efforts to measure and mitigate these impacts.

A Larger Issue: Solar Panel Recycling:

One of the emerging challenges within the solar panel industry is the recycling of end-of-life panels. As the Solar Energy Industries Association (SEIA) aims for solar energy to account for a substantial portion of energy generation, the issue of recycling becomes increasingly pressing. Currently, there is no comprehensive system for recycling old solar panels, and recycling options remain limited. The materials within solar panels, including precious metals, offer the potential for resource conservation and reduced environmental impact through recycling.

How Much Better is Solar for the Environment?

Despite the environmental considerations surrounding solar panel manufacturing, it is important to emphasize that solar panels remain an environmentally superior option compared to conventional non-renewable energy sources. Studies consistently reveal that the carbon footprint of solar panel production pales in comparison to that of coal, natural gas, and other fossil fuels. Furthermore, solar energy generation produces zero emissions once panels are in operation, making it a crucial tool in the fight against climate change.

Conclusion:

Solar panel manufacturing is a sophisticated and multi-faceted process that balances automation for precision with manual work for quality control. While addressing the environmental footprint associated with production is vital, solar panels represent a critical solution for reducing carbon emissions and advancing sustainability. As the industry continues to evolve, it must adapt to minimize its ecological impact and work towards comprehensive recycling solutions to address the growing number of solar panels in circulation. The transition to renewable energy sources like solar power is a pivotal step in the global effort to combat climate change and create a sustainable future.