Babu Chalamala

Presentations:

Tutorial on Grid Energy Storage Technology and Applications

This 4 or 8 hour tutorial covers the basics of electrical energy storage (primarily for the grid), including the factors driving the need for electrical energy storage; the various energy storage applications; various present and potential future battery energy storage technologies (BESS), e.g., Li-based, advanced lead-acid, flow batteries, sodium-based batteries, metal-air batteries, and zinc-based rechargeable batteries; commissioning of energy storage systems; engineering of energy storage systems, interconnection with the grid (e.g., IEEE 1547); energy management systems, commissioning, system safety and reliability, and finally, code compliance. 

Energy Storage and the Future Electric Grid

Low cost grid energy storage technology is key to make the electric grid resilient and flexible to accommodate variable generation and demand. The presentation will give an overview of the electric grid infrastructure and the importance of the energy storage for the future grid. This will be followed by a discussion of the limited role energy storage plays in the grid infrastructure and discuss the impediments for large-scale deployment of energy storage technologies. For example, grid scale applications of batteries need technologies that have low cost, and manufacturing processes that are readily scalable for high volume production. I will provide an overview of various battery technologies and discuss recent advances in materials and technologies that offer the promise of low cost, long cycle energy storage systems. Also, the process of transforming batteries into energy storage systems requires a significant level of systems integration including packaging, thermal management systems, power electronics and power conversion systems, and control electronics. In addition, the scale and complexity of large grid scale storage systems impose a complex set of requirements on the safety and reliability. I will review the fundamental safety aspects of grid energy storage and how this safety is connected to electrochemistry of materials, cell level interactions, packaging and thermal management at the cell and system level, and the overall engineering and control architecture of large scale energy storage systems. Finally, I will present some recent examples of large-scale grid storage implementations around the world and discuss scenarios for a future distributed grid architecture with ubiquitous energy storage.

Advances in Battery Technologies for Electric Vehicles and Grid Storage

Rechargeable batteries have been critical for the rapid growth and success of portable electronics and communications devices. As we look into the future, energy storage technology has the potential to transform nearly every aspect of how we use electrical energy, especially in electrification of transportation, large scale integration of renewable resources, and for modernizing the electric grid. At the core of this future is the need for low cost energy storage systems with high energy density, safety and reliability across a range of sizes and scales from single cell batteries for portable electronics, to 100 kWh systems for electric vehicles, and even larger MWh to GWh systems for applications in the electric grid.

Current energy storage technologies based on a variety of rechargeable battery chemistries do not adequately meet the needs for such a transformative future. Current technology has many limitations including limited battery life, slow charge and discharge cycles, and concerns about safety. The shortcomings are closely tied to materials utilization and control. Batteries rely on electrochemical processes for storing energy. Unlike electronic devices which depend on control of electronic processes in semiconductors, batteries depend on electrochemical conversion processes that rely on chemical transformation of materials through oxidation and reduction processes. These reactive processes lead to chemical and structural transformation of materials with many side reactions limiting the long term life, reliability and safety of batteries. Development of energy storage technologies with long life, faster operation, improved reliability and safety require understanding and control of the dynamics that govern electrochemical phenomena. I will give an overview of rechargeable battery technologies discussing advances in Li-ion batteries, lead acid batteries, and emerging technologies such as flow batteries, sodium and zinc based batteries, along with systems engineering aspects in engineering energy storage systems for major applications. I will also discuss recent developments and what the future holds for new battery technologies.

The requirements for energy storage devices and systems for different applications vary considerably. For example, consumer electronics require high volumetric energy density and light weight, while the cycle and calendar life are not as critical. Batteries for wearable electronics adds additional constraints because of the miniature nature of these devices and form factors. Energy storage systems for electric vehicles also need high energy density, along with longer cycle life, fast charging and discharging capabilities, and satisfy stringent safety requirements. For grid energy storage applications, the need is for low cost, long life storage technologies that are scalable for applications in the electricity grid infrastructure. I will give examples across the application spectrum and projected technology roadmaps.