By Karan Sharma
Every solar project relies a critical set of balance-of-system (BoS) components. Among these, cables, connectors and junction boxes form the electrical backbone of solar installations, ensuring a safe and efficient transfer of electricity generated by solar modules. Renewable Watch presents an overview of the current slandscape and technological advancements in solar cables, connectors and junction boxes in India, as well as the future outlook for the industry…
Current status
India’s broader wires and cables industry has been valued at $9.32 billion in 2024 and is forecasted to grow from $10.01 billion in 2025 to $17.08 billion by 2032, at a CAGR of about 7.94 per cent, as stated in the Confederation of Indian Industry’s WireTech 2025 event. Solar is one of the fastest growing segments within this space, pushing manufacturers to scale production of solar-grade cables, invest in electron-beam (E-beam) cross-linking technology and align with the Bureau of Indian Standards (BIS) and the International Electrotechnical Commission (IEC) norms. Recent policy tightening, particularly through revised Quality Control Orders (QCOs) guidelines issued in March 2025, made BIS compliance mandatory for cables, connectors and junction boxes. The QCOs mandate compliance with IS 17293 for solar cables, aligned with IEC 62930 and EN 5068. Connectors and junction boxes must similarly conform to IS 16781 (IEC 62852) and IS 16911 (IEC 6790) respectively. As per a guest article by Shreegopal Kabra, managing director, RR Kabel, in the May 2025 issue of Renewable Watch, these measures aim to curb substandard imports and raise domestic quality benchmarks.
Solar cables
DC solar cables
Direct current (DC) solar cables essentially connect photovoltaic (PV) modules to inverters and the move to 1,500 V DC architectures has raised technical specifications for insulation, UV resistance and moisture protection. Consequently, domestic production capacity has expanded – manufacturers such as RR Kabel, KEI Industries, Polycab and Havells are scaling up. In May 2025, RR Kabel announced plans to invest around Rs 10.5 billion at its Waghodia facility in Gujarat, to enhance the production capacity by 36,000 metric tonnes per annum (mtpa) in addition to the existing 67,200 mtpa. The phased expansion is scheduled for completion by March 2028. Additionally, the company is investing Rs 4 billion in enhancing the production capacity in two phases at its Silvassa unit, with the first 12,000 mtpa phase expected to be operational by March 2026, followed by an additional 6,000 mtpa expected to be operational by December 2026.
In August 2025, the company also announced plans to invest Rs 12 billion over the next three years to expand its manufacturing capacity, with a particular focus on solar cables. The investments are particularly directed towards producing UV-resistant, halogen-free, e-beam cross-linked cables that align with the requisite international standards.
AC cables
At the inverter output, cables must handle medium voltage (MV)/extra-high voltage (EHV) requirements for grid interconnection. This requires 33 kV, 66 kV and even 132 kV alternating current (AC) cables. To meet this, manufacturers are increasing the production of cross-linked polyethylene (XLPE)-insulated MV and high-voltage (HV) cables. For example, KEI Industries is expanding the production of cables across the 33-220 kV range at its Silvassa and Chopanki units, with ongoing investments throughout 2024-25 and 2025-26. Universal Cables Limited, in February 2025, raised its capex from Rs 2.77 billion to Rs 4.82 billion to expand its Satna and Verna facilities. Around 31,575-32,850 km of new MV/EHV capacity is expected to be operational by March 2026.
Solar connectors and junction boxes
Junction boxes are one of the most critical safety components in a PV module, serving as the interface between solar cells and external DC cables. In this segment as well, domestic manufacturers are scaling up. DhaSh PV Technologies, a key manufacturer of solar junction boxes and connectors, announced plans, in May 2025, to expand its annual production capacity from 40 GW to 63 GW, and produce 1,000 km of solar cables daily. Additionally, the company is focusing on research and development (R&D) of HV connectors and innovative junction box designs, and investing in automation and smart production processes. The company is also planning backward integration through an upcoming gigafactory in Sira, Tumkuru district, Karnataka.
Connector manufacturing is also shifting from imports to domestic production. While MC4-compatible connectors were earlier dominated by international companies such as Stäubli and Amphenol, Indian manufacturers such as Elmex and Connectwell now produce IP68-rated model with weather protection, lower contact resistance and higher current-carrying capacity. These meet both international standards as well as operational demands of utility-scale and rooftop solar projects.
Technological advancements
Cables
On the technological front, solar cable manufacturing has undergone significant advancements. E-beam cross-linking is increasingly replacing chemical cross-linking. This process ensures uniform curing of insulation, superior UV and thermal stability, and higher mechanical strength. Aluminium-core solar cables are being introduced as a cost-effective alternative to copper. Smart cables with embedded thermal and current sensors enable real-time monitoring and predictive diagnostics, which benefit large projects that rely on predictive maintenance. Additionally, insulation materials are advancing with a wider adoption of cross-linked polyolefin and halogen-free formulations, mandated under IS 17293. They provide thermal resistance that can operate at 105 °C and are designed to reduce smoke and toxic emissions during fires. These innovations come at a higher unit cost but extend cable service life, supporting the 25-30-year life cycle of PV modules.
With the rise of floating solar projects, manufacturers such as RR Kabel and Helukabel India are developing waterproof and submersible cables resistant to moisture and humidity. Additionally, the use of solar plus battery energy storage systems has increased the demand for shielded instrumentation and control cables that reduce electromagnetic interference, critical for the safe operation of digital substations and inverter systems.
Connectors
Modern PV connectors are now being produced with IP68 ingress protection, tool-free locking systems that reduce human errors and safety-enhancing features such as anti-arc designs and reverse-polarity protection. Additionally, connectors integrated with smart monitoring for fault detection and predictive maintenance are also being explored. These are equipped with embedded sensors capable of detecting overheating or abnormal current flows. Furthermore, as per a guest article by Anil Gupta, chairman and managing director, KEI Industries Limited, in Renewable Watch’s May 2025 issue, plug-and-play connector systems are becoming increasingly popular, as pre-assembled solutions reduce installation time, improve safety and minimise errors in large deployments.
Junction boxes
With modules producing higher currents, particularly with G12 and G12R wafer formats, junction boxes are being designed to handle them without overheating or compromising safety. Similar to connectors, junction boxes are now also being designed with IP68 ingress protection. Most junction boxes now incorporate advanced polymers such as Xyron 644z that have a thermal index of 125 °C, and UL-94 V0 and 5VA fire resistance standards. Diode technology has also advanced, with double-trench bypass diodes offering better thermal management and higher switching rates, compared to single-trench variants.
Outlook
The continued evolution of solar cables, connectors and junction boxes is critical to India’s solar growth. Enhanced quality enforcement through BIS QCOs, combined with technological advancements and increasing domestic manufacturing investments, has already strengthened the country’s solar supply chain. BoS components such as mounting structures, cables, connectors and junction boxes account for 15-18 per cent of the total costs of utility-scale solar engineering, procurement and construction (EPC) projects, as stated by Richa Varshney, director and business head – renewable energy, Tembo Global Industries Limited, in an interview with Renewable Watch (August 2025 issue). These components, despite their relatively modest upfront cost, have a direct bearing on both project safety and returns. Hence, reliable BoS components are crucial for improving project bankability.
Nevertheless, key challenges persist. In rooftop solar, low-quality and non-compliant imported components are still used due to cost pressures, leading to safety risks and premature failures. In utility-scale projects, developers still face bottlenecks due to limited domestic availability of good quality and QCO-compliant EHV cables, insulation compounds and connectors. Interoperability between connectors and junction boxes from different manufacturers also continues to remain a problem.
Addressing these hurdles will require: first, stricter enforcement of QCOs. Second, targeted financial incentives can further drive the domestic manufacturing of BoS components, reducing market dependence on imports. Third, expanding training programmes for EPC contractors and installers can further ensure correct practices are followed.
Looking ahead, India is poised to not only meet domestic needs but also emerge as a global hub for solar cables, connectors and junction boxes, given the range of developments under way. By ensuring compliance, innovation and coordinated policy support, these BoS components can play a decisive role in further accelerating solar energy uptake in the country.
