Technology Outline (Process Description)

DEVISE aims to create a comprehensive storage system that can efficiently and rationally utilize all forms of energy. This will be achieved by creating a heterogeneous storage facility for diverse forms of energy and facilitating their conversion from one form to another to optimally cater to different loads.

Thermal Energy Storage: Our primary goal is to develop a thermal energy storage system and seamlessly integrate it with both an electrical and biogas storage system. To evaluate Thermal energy storage system performance, we conducted an experimental analysis using a 4.4 m² solar thermal concentrator coupled with a sensible-type thermal energy storage (TES) unit. Within this system, we employed a thermic fluid called Therminol as the working fluid and storage medium for the TES. Throughout the experiment, we recorded solar intensity levels ranging from 400 to 800 w/m2. During the charging phase of the system, we observed that the storage tank temperature reached a maximum of 185°C. Furthermore, the thermal efficiency of the overall system was determined to be approximately 55-60%. This finding indicates the system’s ability to effectively capture and store thermal energy. The total maximum energy storage capacity of this integrated system amounts to 14 kWh which can be used for space heating and cooking. The thermal energy stored in this way can also be utilised in form of small portable cylinders for the purpose of space heating.

Electrical Energy Storage: This proposes the development of hybrid battery storage containing different types batteries operating based on the conditions and their characteristics/parameters.

System Architecture: DC-DC converters linking PV systems and multiple BESSs to a common DC bus.

Modeling: Nonlinear model development, linearization, and validation.

Control Scheme: Outer voltage controller or secondary controller: Maintains a constant DC bus voltage.

Battery reference current generation: Generates reference currents based on various battery parameters such as SOC, internal resistance, temperature, cost, life cycles, etc.

Inner current controllers: Regulate battery currents or inductor currents to their reference values.

Battery Thermal Characterization: The objective of this work would focus mainly on the heat generation estimation for Li-ion batteries through model development and experimentation.Battery health parameters like Capacity, SoC, DoD are correlated with temperature that can be used for heat generation estimation at different the operating conditions.