The use of combined heat and power (CHP) plants and renewable energy sources reduces the amount of greenhouse gases released into the atmosphere and helps to alleviate the consequent climate change. The policies of many governments suggest that the proportion of electrical energy produced by these sources will increase dramatically over the next two decades. Unlike traditional generating units, these new types of power plant are usually 'embedded' in the distribution system or 'dispersed' around the network. As a result, conventional design and operating practices are no longer applicable; for example, power protection principles have to be revised and complex economic questions need to be resolved.

In a provocative study on comparative empire, noted historians identify periods of transition across history that reveal how and why empires emerge. Loren J. Samons on Athens and Arthur Eckstein on Rome examine classical Western empires. Nicholas Canny discusses the British experience, Paul Bushkovitch analyzes the case of imperial Russia, and Pamela Kyle Crossley studies Qing China’s beginnings. Frank Ninkovich tackles the actions of the United States at the turn of the twentieth century, which many view as imperial behavior.

What were the critical characteristics that distinguished the imperial period of the state from its pre-imperial period? When did the state develop those characteristics sufficiently to be called an empire? The authors indicate the domestic political, social, economic, or military institutions that made empire formation possible and address how intentional the transition to empire was. They investigate the actions that drove imperial consolidation and consider the international environment in which the empire formed. Kimberly Kagan provides a concluding essay that probes the historical cases for insights into policymaking and the nature of imperial power.

A companion to Embedded Generation (IET, 2000), this book is a timely publication for an evolving industry. Renewable energy, ancillary services and deregulation of the power industry are changing electricity delivery networks. Microgrids, smartgrids and active distribution networks require a sound understanding of the basic concepts, generation technologies, impacts, operation, control and management, economic viability and market participation involved in grid integration. Practicing engineers in utilities and industry, researchers and students will appreciate this lucid description of the technologies that will enable future electricity systems.