This second edition of the course Solar Energy teaches you to design a complete photovoltaic system. It introduces you to the technology that converts solar energy into electricity, heat and solar fuels with a main focus on electricity generation. Photovoltaic (PV) devices are presented as advanced semiconductor devices that deliver electricity directly from sunlight. The emphasis is on understanding the working principle of a solar cell, fabrication of solar cells, PV module construction and the design of a PV system. You will understand the principles of the photovoltaic conversion (the conversion of light into electricity). We will explain the advantages, limitations and challenges of different solar cell technologies, such as crystalline silicon solar cell technology, thin film solar cell technologies and the latest novel solar cell concepts as studied on lab-scale. The course will treat the specifications of solar modules and show you how to design a complete solar system for any particular application. The suitable semiconductor materials, device physics, and fabrication technologies for solar cells are presented.