Solar energy is booming, and solar panel manufacturing is at the heart of this revolution.
As demand for clean energy soars worldwide, manufacturers face increasing pressure to make panels more efficient, durable, and cost-effective. However, achieving this balance is easier said than done.
In this article, we’ll explore how solar panels are made and the biggest challenges faced within the solar energy supply chain.
We’ll also cover recent improvements and opportunities to overcome these challenges, including laser technology.
Table of Contents
In our previous article about solar cell manufacturing, we covered how the key component of solar panels is made from either crystalline silicon (monocrystalline or polysilicon), amorphous silicon or cadmium telluride for thin-film solar panels.
Here, we’ll consider the manufacturing process of solar cells as complete and move on directly to solar panel production:
First, the solar cells are connected together in a solar module manufacturing facility. During this step, a thin metal stringing machine ensures the cells are correctly aligned and solders them to form PV modules (also called solar modules).
Depending on the required current output and voltage, these modules may have different configurations and a variable number of interconnected cells.
The quantity of busbars (metal strips carrying the electric current) applied onto the cells can also vary to meet different efficiency and wear resistance requirements.
Afterward, a layer of ethylene-vinyl acetate (EVA) film encapsulates the solar cells for environmental protection and photovoltaic stability.
Following this encapsulation, a tempered glass cover and a back sheet are added to the solar module to enclose the cells and wiring and prevent the intrusion of water or unwanted materials.
After modules are assembled and thoroughly tested for optimal efficiency, solar panel manufacturers fit them with an aluminum frame and a strong silicon adhesive to seal and protect the edges.
A junction box is then installed on the module’s backside, where circuit ribbons are connected to bypass diodes.
Bypass diodes ensure that the solar power generation output flows efficiently in one direction. Diodes act like one-way electricity valves to prevent reverse flows, which can cause energy loss, equipment damage, and safety hazards.
In solar panels, diodes are also used to bypass malfunctioning or shaded cells (e.g., by clouds or debris) that can create resistance in the current path and cause the “hot spot effect”.
These hot spots are caused by the electrical current coming from the functional cells. Instead of generating a current, shaded cells dissipate energy from non-shaded cells as heat, causing hotter-than-normal areas to appear on the solar panel.
If the current isn’t redirected around the shaded cells, hot spots can reduce panel efficiency and even lead to permanent damage. For this reason, solar panels can’t work without bypass diodes.
Ultimately, the solar energy generated is conveyed through the junction box’s cables to an inverter, where the generated direct current (DC) is converted into alternating current (AC) electricity before being sent to the outer electrical grid.
Although the production costs of solar photovoltaics have already dropped 90% over the past decade, efficiency improvements remain crucial to ensure further cost reductions and competitiveness in the clean energy market.
Producing higher-efficiency solar panels is more expensive. For this reason, solar panel manufacturers must adapt to the need for affordable solar energy despite the cost of high-performing raw materials like perovskite and silicon used to make multi-junction solar cells.
To help overcome this challenge, the solar industry currently focuses on improved solar technologies, such as TOPCon solar cells and Heterojunction (HJT) solar cells.
These innovative solar PV components have shown up to 25% per-square-meter efficiency gains and integrate relatively well into existing production lines.
Further research is ongoing to lower the production cost of these improved solar technologies.
Over time, the degradation of key materials and components impacts performance. Solar panels must also resist tough environments, from scorching deserts to freezing winters.
These reasons have pushed solar companies to develop more durable and resilient designs such as multi-junction cells, which combine crystalline silicon and perovskite.
While remaining economical, this hybrid technology delivers higher energy outputs, making a solar panel more efficient for the first 10 to 15 years of its 30 to 40-year lifespan.
Self-cleaning nano-coatings are also being developed to maintain optimal efficiency even in the most dust-prone areas, as shown in this video:
The solar photovoltaic supply chain is complex. Multiple factors, including international trade restrictions and tariffs, technical challenges and shortages of key materials (e.g., polysilicon and silver), often cause delays among solar companies.
Because key components in the solar photovoltaics supply chain are produced in concentrated areas of the world (e.g., China), international trade has been critical to enable solar panel manufacturing at scale.
However, the International Energy Agency reported that the number of import duties and taxes increased tenfold in the last decade. Such an expansion of trade restrictions has a risk of slowing down the global implementation of solar technology and other renewable energies.
On the technical side, the steps preceding the assembly of cells into solar modules (silicon ingots slicing, wafer texturing, doping and coating) require extreme precision and accuracy for optimal efficiency and durability.
Maintaining such standards through an increased manufacturing capacity requires innovative approaches, such as AI and automation.
AI-driven quality control can improve production by spotting solar panel defects early in the manufacturing process, as achieved by Vikram Solar’s Tamil Nadu facility.
Industrial automation can also increase productivity and repeatability in various applications, including welding, cleaning, texturing and marking.
Lastly, the highly concentrated production of critical minerals used in solar PV manufacturing faces a rapidly increasing worldwide demand. An imbalance between supply and demand can eventually lead to shortages and tremendous cost increases.
On the other hand, copper paste is increasingly used to replace silver contacts in solar panels because of its affordability, similar conductivity and significantly higher abundance.
3D printing of conductive components is also an emerging trend that could reduce reliance on silver while lowering costs.
Solar panels produce clean energy, but their manufacturing process can be resource intensive. For example, importing raw materials has an inherent carbon footprint, and manufacturing silicon semiconductors requires enormous amounts of water.
Reducing waste, energy consumption and water use is crucial for sustainable production.
Reports have shown that recycling solar PV panels could meet a significant part of the industry’s demand for materials (e.g., silicon, silver, copper, aluminum and glass).
Recovering semiconductor materials from used panels, for example, can improve sustainability and reduce the manufacturing facilities’ carbon footprint.
The public’s rising concern for the potential presence of PFAS in solar modules, among other considerations, also pressures the solar industry to adopt more sustainable practices.
For example, using green solvents or solvent-free material treatment processes (e.g., laser cleaning and texturing) is becoming increasingly popular.
The advantages of automated laser technology are numerous, from reducing waste and material consumption to improving cycle times and repeatability.
Manufacturing solar panels using one or multiple laser processes is a way to:
Laserax currently supports the solar industry in two key applications:
Laser edge deletion: A highly precise, non-contact solution that can remove edge coatings from thin-film solar panels efficiently.
Thin-film cleaning for recycling: An advanced and green cleaning process that makes the recovery of valuable solar PV materials extremely easier.
Would you like to discuss your application with an expert?
Dr. Annick Anctil is an Associate Professor at the Michigan State University’s College of Engineering, where she leads research on anticipatory sustainability assessment. She uses proactive sustainability assessment to reduce the environmental and cost impact of new technologies. The core of her research is evaluating the environmental impact of photovoltaics and battery technologies, particularly the effect of mining and recycling materials for energy applications.
Solar cell manufacturing has evolved significantly in recent years. As solar energy is predicted to experience extraordinary growth, the near future will likely be marked by even more technological innovations. In this article, we’ll cover the steps of the solar cell manufacturing process. We’ll also highlight challenges and advancements to make solar photovoltaic cells more efficient and sustainable.
