NEWS – Global energy demand is rising, and clean storage technologies are crucial to reducing fossil fuel dependence. Thermochemical energy storage using Strontium bromide hexahydrate (SrBr₂·6H₂O) is emerging as a promising solution, especially for heating homes in cold regions.

HIGHLIGHTS

How It Works

• SrBr₂·6H₂O stores energy via reversible hydration–dehydration reactions at temperatures below 100 °C.
• In summer, it absorbs heat and converts to SrBr₂·H₂O (endothermic).
• In winter, it rehydrates, releasing stored heat (exothermic).
• The monohydrate remains stable for months, allowing storage and transport to remote areas.

Indian Innovation

Researchers at IIT Bombay and NIAS Bengaluru developed a self-contained thermal storage unit comprising:

• A solar collector
• Reactor chamber with SrBr₂·6H₂O
• Air circulation system
• Weatherproof casing insulated with glass wool for Himalayan use

The system has been peer-reviewed in Applied Thermal Engineering and Renewable Energy.

Benefits for the Himalayas

• Suited for isolated households that currently depend on diesel or firewood.
• Tested under six charge–discharge cycles without performance loss; estimated life ~600 cycles.
• Field trials in Leh, Shimla, Manali, Darjeeling, Dehradun showed lowest heating cost (Rs 31/kWh-thermal in Leh), cheaper than diesel-based heating.
• Indian Army considering trials in high-altitude camps.

Challenges

• SrBr₂ is hygroscopic; in humid conditions, salt crumbles, reducing life span.
• Mitigation: mix with silica gel (3:1 ratio) for structural stability.
• Extraction and disposal may cause ecological harm; safe handling and protocols are essential.

Economic Viability

Prof. Sandip Saha (IIT Bombay) highlights that dehydrating salt in sunny plains and transporting it to mountains can be cost-effective. Compared to solar panels with battery storage, direct thermochemical storage avoids battery losses in cold nights, providing consistent heating.