Book excerpt: The electric power industry is undergoing the greatest transformation in its 100-year history. In readable, concise fashion, author Denise Warkentin explains how the electric industry works and what changes are in store. After briefly tracing the history of the industry, she details how different segments are structured and work together. Investor-owned, consumer-owned, and government-owned utilities are explained, as are rural cooperatives and independent power producers. Other issues addressed include deregulation, the emergence of energy marketers, and the impact of ongoing mergers, acquisitions, and consolidations.