India became home to the world’s first-ever thermal battery plant, that was inaugurated in Andhra Pradesh on Monday. This plant aims to create a new energy storage form that is expected to have commercial applications, while also maintaining a low carbon footprint, and being less dependent on external factors like weather. The thermal battery facility, to be owned by Bharat Energy Storage Technology Private Limited (BEST), will be inaugurated by Andhra Pradesh Chief Minister N Chandrababu Naidu, and could provide energy solutions for electrical grids, transport and telecom services. Before we look at its applications, here is a lowdown on the science behind thermal battery technology.
Thermal battery technology: How it works
Conventional battery technology is based on the system of charging/discharging cycles that are driven by electricity. For example, the Lithium-ion battery, a staple of many electronic devices, consists of electric charges being transferred from electrodes. Energy is derived from this battery, when lithium atoms turn into lithium ions (Li+), and get stored when this reaction reverses. Therefore, Li-ion batteries work on the basis of electrical energy.
Thermal batteries, on the other hand, use thermal energy to operate, i.e., the energy created by temperature differences. Therefore, the energy transfer in thermal batteries helps store heat when heat travels from one part of the battery setup to the other. For that to happen, a thermal battery consists of two parts: a cool zone known as sink, and a hot source called source. Both these sides consist of compounds known as phase-changing materials (PCMs), which can change their state of matter on the basis of a physical/chemical reaction.
When the sink of a thermal battery receives heat, it transforms physically or chemically, thereby storing energy, while the source cools down. During operation, the sink is cooled down, so it releases the stored energy, while the source heats up. Depending on the nature of the battery, the system can derive heat from any source, which makes a thermal battery very versatile. Thermal battery technology was patented in India by Dr Patrick Glynn in 2016.
Thermal battery technology: Integration with power grids
Given the positives from thermal battery technology, its main application lies in the possible integration with power grids, that can help industrial demand, while also supporting public transport systems and telecom grids. In the field of power transmission, thermal batteries will be able to function as long as there is a heat source to drive their operation. This could help solve power issues in remote areas, and also address rising energy requirements from regional or national grids. Power-intensive industries will also be major beneficiaries, and the transformation will mean reduced dependence on fossil fuels for energy. Telecom infrastructure is also a target area, as thermal batteries will help maintain signal strength and network connectivity. This, in turn, could also improve internet penetration and ultra-fast mobile services.
At the initial stage of commercial operations, set for May 2019, BEST plans to create a battery capacity of 1000MW. This is expected to be upgraded to a 10GW capacity by 2025.
Thermal battery technology: E-vehicle manufacturing
Another area that could receive impetus from thermal batteries is that of electric vehicles. Prime Minister Narendra Modi had stated that by 2030, India’s automobile industry will completely rely on manufacturing of e-vehicles. Currently, Tata and Mahindra are the only domestic firms working on such transport systems. With thermal battery technology, car makers could consider going green, and deploy clean energy at minimal maintenance costs. At the same time, e-vehicles could also derive charging power from stations that run on thermal batteries. In AP plant, BEST aims to setup an electric truck that can run up to 800kms on a single charge.