TERI Energy & Environment Data Diary and Yearbook (TEDDY) is an annual publication brought out by The Energy and Resources Institute (TERI) since 1986. It is the only comprehensive energy and environment yearbook in India which provides updated information on the energy supply sectors (coal and lignite, petroleum and natural gas, power, and renewable energy sources), energy demand sectors (agriculture, industry, transport, residential, and commercial sectors), and environment (local and global). The publication also provides a review of the government policies that have implications for these sectors of the Indian economy. Each edition of TEDDY contains India's commercial energy balances for the last four years that provide comprehensive information on energy flows within different sectors of the economy and how they have been changing over time. These energy balances and conversion factors are a valuable ready reckoner for researchers, scholars, and organizations working on energy and related sectors. After the introductory chapters, for the ease of readers, TEDDY has been divided into sections on energy supply, energy demand, and local and global environment. The thirtieth edition of the publication, TEDDY 2015/16, comes with several interesting features. The Green Focus at the end of each chapter highlights sustainable initiatives and successful practices, which are of current interest in the sectors discussed under the sections on energy supply, energy demand, and local and global environment. The publication also features a section that discusses sustainable development goals and air pollution and health. Interactive graphs, figures, maps, and tables have been used throughout the chapters to explain facts, which make the book an interesting read. In addition, detailed tables at the end of each chapter represent statistical data on each of the above-mentioned sectors. The publication is accompanied by a complimentary CD containing full text. The publication has more than 15,000 readers across the globe and is often cited in international peer reviewed journals and policy documents.