To achieve the goal of carbon neutrality by the middle of the century, renewable and sustainable energy will play a key role. In this course, the main renewable and sustainable energy systems such as solar, wind, hydropower, biomass, nuclear energy, fuel cell will be introduced. As the energy storage systems are needed to smooth the intermittent manner of renewable energy systems, the different battery energy storage systems will be covered in the course. The system designs, operations and principal theories will be introduced in this course. For students who will work or further study in the energy related areas after graduation, this course will especially be helpful. For those students not working in energy areas, it is still helpful as the usage of clean energy will inevitably be part of our future life.