A concise analysis of the complex issues surrounding the world’s transition to renewable sources of energy. While the voices of partisans are loud, emotional, and often irrational, Usher (Faculty Director/Tamer Center for Social Enterprise, Columbia Business School) is calm and devoted to the facts, reporting on the current market and noting trends. He describes his book as “a primer on the economic fundamentals driving the global transition to renewables,” which is an apt description: He provides a compact source of information for the public, consumers, investors, and policymakers on the inevitable transition and its possible consequences. Putting renewables in perspective, Usher looks back at the transition from wood to coal and from coal-fired electricity to nuclear-powered (which he dismisses as a now diminishing option) and gas-powered electricity. Transitions, he points out, are driven largely by economics, they are often hampered and slow, and they have both positive and negative consequences. Much of the material here is from the author’s courses at Columbia Business School. While nonstudents may find some of the formulas, graphs, and charts daunting, the text is generally straightforward and highly readable, and there is a useful glossary. Usher focuses on two particular sources of renewable energy: wind and solar, both of which, under currently available technologies, are unlimited and globally abundant. China and India, he demonstrates, are taking the lead in the transition; the five largest solar firms are located in these two countries, and China is now the world’s single largest market for electric vehicles. The author also looks at the implications for oil-producing nations such as Saudi Arabia. The chapter on financing, which includes a discussion of the challenges and major hurdles, will be of special interest to investors. In the final chapter, Usher rightly stresses the inevitability of the transition and the need to accelerate the process. Balanced, articulate, and informative.