As rooftop solar installations under the PM Surya Ghar: Muft Bijli Yojana reach 1 million nationwide, concerns have arisen about the lack of quality checks for the components and the absence of standardization.

Several new installers with little or no experience have entered the rooftop solar market to cash in on the increasing consumer demand. Industry insiders say the quality of the installations is being compromised in a rush to meet targets in some states.

According to Mercom India Research’s Q4 & Annual 2024 India Rooftop Solar Market Report, the country installed 3.2 GW of rooftop solar capacity in 2024, an 86% increase from 2023.

In Kerala, which transitioned from its state program to the PM Surya Ghar program, some mandatory quality tests have been ignored. For example, a power quality testing report was mandated under Kerala’s Soura subsidy program for a net metering connection. These tests have been disregarded as REC, the nodal agency overseeing PM Surya Ghar, does not insist on the power quality test report.

Reputed rooftop solar installers also highlighted the lack of standardization when it comes to the various components in rooftop solar installations. They referred to the lack of uniformity in frame structure, module, and cell size in installations, which could cause issues for consumers in the long run.

Another worrying trend is the increase in module capacity and size without a parallel module frame size increase.

Tinsu Mathew, Managing Director of El Sol Power Solutions, explained that earlier, the industry standard used to be a 40mm module frame, but some are going for 35mm and 30mm frames. The module size used to be 1.6m X 1m for a 250 W module, but it has gradually increased to 2m X 1m and up to 2.1m X 1m.

“In such cases, the center part of the module needs extra support with at least three purlins. Otherwise, there could be a bend in the module, leading to issues in the future. Some installers are not considering this. The module frame size used for the earlier module size is still being used,” he said.

Module manufacturing plants with smaller capacities also face technical limitations that lead to a drop in module quality. “Even in fully automated module manufacturing plants, some tasks are always manually executed. Smaller plants may have a technology limitation or may not even choose Tier I bill of materials. Top-end manufacturers avoid such problems,” Mathew said.

Improper module back-frame pasting and cell alignment, as well as the absence of cell color sorting, are some of the other issues that could impact module performance. There are also instances of increased light-induced degradation leading to a drop in module performance.

Such modules are being sold at cheaper prices.

The problem also lies in a lack of awareness among customers about rooftop solar systems. “Engineering, procurement and construction contractors push for a less expensive rooftop solar system to stay competitive. They push for smaller brands, but customers may not be aware of the difference,” Mathew said.

Sreeja, Manager of Operations at Wattsun Energy, said some modules show quality issues within a year because of cell alignment and segmentation issues. The problem also lies with a shortage of Tier 1 modules.

Multiple checks like I-V curve tests should also be done, indicating whether a panel is operating at peak efficiency.

While there is a rising trend towards bifacial modules, a lack of technical knowledge about mounting structures leads to many installations failing to optimize bifacial performance. Purlins can cast shadows on the rear of bifacial modules, significantly reducing energy gain from reflected sunlight.

Quality issues are also being seen in inverters. Due to a lack of expertise, some installers use single-phase inverters instead of three-phase in 5 kW systems without proper earthing.

Some installers also replace double maximum power point tracking (MPPT) inverters with single MPPT ones or use new inverter brands that offer a better warranty and discount to lower the project cost.

Industry experts caution that the lack of oversight over new installers and brands for components entering the market could derail rooftop solar initiatives. They say that even companies registered under the Approved List of Models and Manufacturers are also known to compromise on quality in solar modules.

They suggest that the Ministry of New and Renewable Energy should publish standards for various components of rooftop solar systems, including module frames, mounting structures, and system weight.

Distribution companies need to be made aware of these issues and trained about the technical and engineering aspects of rooftop solar systems so that quality is maintained in the installations. They should also conduct all the required tests before the systems are installed.

The strong consumer demand for the PM Surya Ghar: Muft Bijli Yojana and installation figures indicate initial success. However, If consumers start to experience performance issues, confidence in residential rooftop solar may decline. Government agencies must proactively set balanced quality standards without slowing down installations for the continued long-term success of the program,” said Raj Prabhu, CEO of Mercom Capital Group.