In India, the choice of solar modules is often between PERC (p-type) and TOPCon (n-type) cells. In the future, heterojunction technology (HJT) will also be available.

The efficiency of a solar cell module is a key factor — namely, how well it can convert sunlight into electrical energy. Currently, TOPCon cells stand out with an efficiency of 21-23 percent, compared to 20 percent efficiency of PERC cells. This means that TOPCon modules generate more electricity under the same sunlight conditions.

The module capacity is measured at 25°C. Each degree increase in the ambient temperature reduces the effect by 0.3-0.5 percent. This reduction in is less in the case of TOPCon, making it a better choice.

PERC modules are more cost-effective in the Indian market, at INR 1–1.5 per watt-peak (Wp).

Although technical criteria favor TOPCon, there is limited availability of these modules with India-made cells (only India-made solar cells are eligible for PM Surya Ghar subsidy).

Another consideration is the availability of unshaded roof space. Between two modules occupying a similar space, the more efficient one usually generates more current. If there is less shadow-free area, TopCon is recommended.

Bifacial solar panels are designed to capture sunlight on both sides, allowing them to utilize both direct sunlight and reflected light from the ground. This can increase the total energy yield. Bifacial modules provide an additional 1-2 percent output compared to monofacial modules.

The roof and the characteristics of the site play an important role in this choice. Bifacial modules work best in environments with high ground reflectivity, such as bright or reflective surfaces.

The effectiveness of bifacial technology may be limited if the ceiling surface does not provide significant reflectivity. In addition, the height of the installation is crucial, as elevated installations can capture more reflected light, leading to greater energy gains. Bifacial panels often require specific mounting systems to optimize the double-sided energy collection.

Analyzing the return on investment (ROI) of bifacial modules is crucial; while the increased energy yield can often offset the slightly higher initial cost, factors such as location, roof reflectivity and efficiency gains will affect the overall outcome.

It appears that most TOPCon module suppliers standardize around n-type bifacial modules. You can therefore get the advantage of bifacial technology as standard.

A TOPCon module today costs around INR 23 per Wp if the facility compulsorily uses India-made modules (‘domestic content requirement’ or DCR), or INR 13.50 per Wp without DCR. Mono-PERC is around INR 2 cheaper.

Under ideal conditions, the TOPCon model can produce 4-4.5 percent more than a PERC module.

The process begins with understanding the two primary types of warranties offered by manufacturers. A product warranty usually covers defects in materials and workmanship and can range from 10 to 12 years. A performance guarantee guarantees that the solar module will maintain a minimum percentage of its rated output over time. According to guidelines from the Ministry of New and Renewable Energy, the guarantee must ensure that the modules deliver at least 90 percent of their rated output for the first 10 years and no less than 80 percent for the subsequent 15 years.

A customer can ensure that the warranty is not subject to any conditions by reading the limitations and exclusions sections.

Generally speaking, a module manufacturer’s warranty does not cover naturally occurring scratches, stains, mechanical wear, mold, rust and discoloration and other conditions that do not affect the performance or mechanical strength of the modules. Discoloration of snail tracks, cell finger and cell collection rail is also not covered.

However, some specific conditions may void the warranty, such as damage caused by improper installation or defective wiring, fire, power failure, natural disasters, vandalism, or accidental breakage.

In addition to a visual inspection for visible cracks, chips or scratches on the glass surface and a check for bubbles or delamination that may indicate defects, it is important to request documentation from the installer, including electroluminescence test results (EL testing) and quality certifications such as IEC standards.

After installation, customers can monitor energy production using the system’s performance monitoring tool, to track production levels, alerting to any sudden drops or inconsistencies.

The solar solution provider must share all the above details and ensure that the factory audit is completed before the modules are purchased.

Start by choosing panels certified to recognized standards, such as International Electrotechnical Commission certification IEC 62804-1, which confirms that they have undergone rigorous testing for performance and durability, particularly for thermal degradation and PID.

Important installation practices include placing the panels in well-ventilated areas and avoiding concentrated light in specific locations. This can help prevent thermal degradation and PID, increasing efficiency.

Consider using PID-resistant techniques. Some manufacturers offer modules specifically designed to minimize PID risks through advanced materials and construction techniques.

Regular maintenance and monitoring is critical to the health of your solar panels. Check regularly for signs of wear or damage, such as discoloration or performance changes, and perform preventive maintenance as needed. Use monitoring tools to track energy production.

Finally, keep the panels clean. Accumulated dirt and debris can impede efficiency and raise panel temperature, reducing efficiency. Regular cleaning helps ensure optimal performance and maximize energy production.

One of the first steps is to determine the electricity consumption and sanctioned load for the site. Electricity usage patterns help determine the capacity requirement of the solar PV system. A shadow study will be needed to identify the shadow-free area of ​​the site. This is done using a software application, which helps to evaluate potential obstacles such as nearby buildings, trees or other structures such as water tanks, understand the roof structure and dimensions and how shadows change during the day and over the seasons.

Another consideration is the orientation and tilt of the panels. Placing the panels to face south maximizes exposure to sunlight, while adjusting the tilt based on geographic location can further optimize energy production. Adequate spacing between panels is critical, as it helps reduce shading from adjacent panels and allows airflow for cooling, which is especially important in ground-mounted systems. Additionally, designing the layout to facilitate easy access for maintenance and cleaning will ensure that the system remains efficient over time.

A minimum distance of 1 meter between the structure and the parapet wall on all sides is recommended. Regular cleaning schedules are important, especially in high dust environments, to maintain optimal panel efficiency.

Evaluating the load bearing capacity of the roof will confirm if it can support the weight of the solar panels and mounting system. Placing inverters in shaded, well-ventilated areas helps maintain optimal operating temperatures.

Once the design is complete to place the modules, mounting structures, components and earth protection, the system is ready for installation.

During construction of columns for elevated modular assembly, drilling in RCC terrace slabs requires extreme care due to varying slab thickness and inconsistent construction quality at different locations. It is necessary to use high-quality chemical anchors to ensure roof stability and waterproofing.

Important considerations include:

● Correct module handling to prevent damage

● Avoid hotspot formation due to shadowing, which can void warranties

● Maintain prescribed inverter clearance (according to manufacturer’s manuals) for optimal ventilation and efficient operation

Strict adherence to these guidelines ensures:

● Optimal system performance

● Reliability and durability

Prioritizing these specifications during construction is critical to ensuring a well-designed and efficiently operating solar energy system.

The design of PV systems prioritizes personnel and system safety, taking into account potential hazards and risks. Site assessments identify high-risk installation and maintenance activities, inform targeted safety protocols and provide safety protection systems.

For solar installations with a lifespan of more than 25 years, it is crucial to minimize maintenance risks. Simple methods such as cable marking, proper torque tightening, and attaching mounting bolts with torque indicators facilitate maintenance.

Torque marking, although small, is important in systems with many bolts. It enables quick inspections, reduces step-related risks and fatigue. This practice improves system reliability, reduces maintenance costs, and improves the safety of maintenance personnel, ultimately extending the life of the system.