Retail and wholesale businesses with substantial daytime electricity consumption can use rooftop solar to offset grid power purchases during operating hours. Stores with lighting, cooling, ventilation, and other daytime electrical loads can consume solar power as it is generated, reducing their electricity bills.

Ratna Store, a clothing and uniform retailer and wholesaler in Kollam, Kerala, has installed a 20 kW rooftop solar system to reduce its electricity expenses. High power bills were the main reason the business switched to solar.

Wattsun Energy India installed the rooftop system.

Before the installation, Ratna Store consumed about 70 kWh to 100 kWh of electricity per day, or about 2,100 kWh to 3,000 kWh per month.

The solar system is expected to reduce the store’s electricity expenses by approximately ₹16,000 (~$166) to ₹20,000 (~$208)/month, resulting in annual savings of ₹192,000 (~$2,000) to ₹240,000 (~$2,500).

Based on the estimated savings, the project is expected to recover its investment in approximately 3.3 to 4.2 years.

The system uses Reliance heterojunction technology (HJT) solar modules and Sungrow inverters. Wattsun used continuous long-rail mounting structures along with fiber-reinforced polymer (FRP) walkways.

The wide roof span presented alignment and access challenges during installation. Wattsun used the continuous long-rail mounting structures to maintain alignment and distribute loads evenly across the rooftop.

The FRP walkways provide maintenance access across the rooftop while adding relatively little structural load. Their non-conductive and corrosion-resistant properties also make them suitable for rooftop electrical installations. The design lets cables run beneath the system and gives maintenance personnel dedicated access without stressing the solar modules.

“By pairing custom long-rail mounting with lightweight, non-conductive FRP walkways, our engineering team delivered a seamless 20 kW installation that prioritizes long-term structural safety, effortless maintenance, and maximum solar yield,” said Terance Alex, Founder & CEO at Wattsun Energy India.

Wattsun had recently installed a 20 kW rooftop solar system at Vintage View, a residential apartment complex in Thiruvananthapuram, Kerala, to reduce its electricity bills.

To raise awareness about the benefits of solar projects, Mercom India has been hosting a pan-India C&I Clean Energy Meet series, bringing renewable energy developers and commercial and industrial power consumers together to discuss clean energy adoption. The next event in the series will be held in Visakhapatnam on September 24, 2026.