This document provides an overview of energy storage systems and technologies. It discusses the relevance and need for energy storage given increasing energy demand and a shift to renewable energy sources. It covers various types of energy storage technologies including mechanical, chemical, thermal, and electrochemical storage. Specific technologies discussed in more detail include pumped hydro storage, compressed air storage, batteries focusing on lithium-ion batteries, and fuel cells. The document also discusses objectives, syllabus, and textbooks for the course.