CSIR-NAL and Supreme Solar partner to revolutionise solar water heating. Here’s how…

Bengaluru:  In a significant stride towards self-reliance in renewable energy technology, CSIR-National Aerospace Laboratories (CSIR-NAL) have signed a Transfer of Technology (ToT) agreement with M/s. Supreme Solar Pvt. Ltd. for the application of its groundbreaking NALSUN-NGTM coating technology.

This eco-friendly, sprayable coating, designed for high-efficiency flat plate solar water heaters, marks a crucial step in reducing India’s dependency on imported solar components while advancing sustainability goals.

A breakthrough in solar absorber coatings

NALSUN-NGTM is an advanced graphene oxide-based solar absorber coating that sets a new benchmark in solar thermal applications. Unlike conventional coatings, it uses water as a solvent, eliminating volatile organic compounds (VOCs) and hazardous chemicals.

Fully compliant with RoHS and REACH regulations, the technology is a testament to CSIR-NAL’s commitment to developing scalable, cost-effective, and environmentally sustainable solutions.

Developed by Dr. N. Selvakumar, Principal Scientist, G. Srinivas, STO, and Dr. Harish Barshilia, Chief Scientist at CSIR-NAL, this innovative coating replaces expensive and complex physical vapour deposition processes.

It also surpasses sprayable alternatives that often contain flammable and harmful VOCs, offering a safer, sustainable, and scalable solution for the solar industry.

Transforming solar water heating efficiency

The integration of NALSUN-NGTM coating on aluminium and copper fins in flat plate solar water heaters enhances sunlight-to-heat conversion efficiency up to an impressive 70 percent.

This efficiency translates into substantial energy savings, reducing household electricity consumption by 1,000–2,000 kWh per year and lowering CO2 emissions by 1–2 tons annually.

This innovation directly supports global climate action initiatives and aligns with the United Nations’ Sustainable Development Goals (SDG 7 – Affordable and Clean Energy and SDG 13 – Climate Action).

CSIR-NAL Director Dr. Abhay Pashilkar emphasized the transformative impact of this innovation, particularly in remote villages where access to conventional energy sources is limited.

By replacing traditional electric or gas-powered water heating systems, these solar heaters offer a cost-effective and sustainable alternative.

Boosting India’s manufacturing and clean energy goals

This initiative is a crucial step towards reducing India’s reliance on imported solar components. The country currently imports 5–6 lakh evacuated tube collectors per month, a dependency that NALSUN-NGTM technology aims to curtail.

By fostering local production under the ‘Make in India’ and ‘Atmanirbhar Bharat’ initiatives, the partnership between CSIR-NAL and Supreme Solar strengthens the domestic solar manufacturing ecosystem and supports the National Solar Mission.

Following the technology transfer on February 14, 2024, Supreme Solar Pvt. Ltd. has established a dedicated production facility with technical assistance from CSIR-NAL.

The newly developed 4-metre-long spray pyrolysis plant – the first of its kind in India – enables roll-to-roll application of the graphene oxide-based waterborne coating.

Full-scale production commenced in December 2024, with an initial output capacity of 10 flat plate collectors per day. The company’s Managing Director, Narasimha Pai, has announced plans to expand production to meet rising domestic and international demand.

Future prospects: Beyond solar water heating

Beyond flat plate solar water heaters, the versatility of NALSUN-NGTM extends to applications such as solar desalination, solar drying, and industrial process heat.

With its exceptional durability and a service life exceeding 20 years, the coating represents a long-term investment in sustainable energy solutions.

CSIR-NAL’s partnership with Supreme Solar Pvt. Ltd. exemplifies India’s ability to drive innovation, promote green energy, and reduce carbon footprints. By bridging the gap between research and industry, this collaboration sets the stage for a cleaner, self-reliant, and energy-efficient future.