MIT-WPU Researchers Develop PCM-Based Solar Thermal Battery for Extended Hot Water Supply
Researchers at MIT World Peace University have developed a solar thermal energy storage system that uses a phase change material-based thermal battery to provide hot water for up to 14 hours after sunset.
June 29, 2026. By Mrinmoy Dey
The technology addresses one of the biggest challenges associated with solar energy – its intermittent availability – and has the potential to reduce dependence on electricity and fossil fuels for water heating applications.
Developed by Dr. Anita Nene and Dr. Rohit Ghadge from the Department of Mechanical Engineering, MIT-WPU, the system combines a Scheffler solar concentrator with a thermal storage capsule containing paraffin wax, a phase change material capable of storing and releasing large amounts of heat.
Unlike conventional energy storage systems that rely on electrochemical batteries, the proposed solution stores energy directly as heat. The system incorporates a detachable PCM tube, a water-jacket heat transfer mechanism, and polyurethane insulation to maximise heat retention and energy utilisation.
According to the researchers, the technology achieved complete thermal charging in approximately 18 minutes and complete discharge in approximately 32 minutes during laboratory-scale testing. The system continued supplying hot water after solar input was removed, demonstrating its ability to provide thermal energy beyond daylight hours.
The prototype stores approximately 1.5 to 2 kWh of thermal energy and can maintain water temperatures between 50°C and 60°C for up to 14 hours after charging.
“One of the major limitations of solar energy is that it is available only when the sun is shining. Our objective was to develop a simple, cost-effective, and sustainable thermal storage solution that can store solar energy and make it available whenever required,” said Dr. Anita Nene.
“Thermal energy accounts for a substantial share of overall energy consumption. Technologies that enable efficient storage of solar heat can help reduce dependence on conventional fuels, improve energy security, and support the transition towards cleaner and more sustainable energy systems,” said Dr. Rohit Ghadge.
The researchers conducted Computational Fluid Dynamics (CFD) simulations alongside laboratory-scale validation to evaluate system performance. The technology is currently at Technology Readiness Level (TRL) 7 and is being prepared for pilot deployments in real-world environments.
Potential applications include residential water heating systems, hotels, hospitals, hostels, educational institutions, industrial process heating facilities, community kitchens, agricultural operations, and off-grid rural communities.
An Indian patent application titled “Solar Energy Storage Capsule Using Phase Change Material” has also been filed. The researchers are currently exploring collaborations with industry partners for pilot deployment and commercialisation.
“The next phase of development will focus on field trials, performance optimisation, and scale-up for commercial deployment,” said Dr Nene.
please contact: contact@energetica-india.net.
Bharath Krishna Rao
CEO & Co-founder
India's EV Future Depends on Localised Manufacturing Says Emobi CEO Bharath Rao
Praveen Kakulte
Founder and CEO
O&M of RE Assets Has Evolved into an Intelligence-Led Function: Praveen Kakulte
Raahul Hari Nair
Founder
The Future Belongs to Energy-Intelligent Enterprises, Says CHI'GRIDS' Founder Raahul Hari Nair
Dibakar Roy
Founder and CEO
Automation, AI and Smart Manufacturing Emerge as Biggest Draw at SNEC 2026: Dibakar Roy
Hiren Pravin Shah
Managing Director and CEO
Renewable Expansion Without Storage will put Increasing Stress on the Grid: Hiren Pravin Shah