How Solar Energy Became Cheap: A Model for Low-Carbon Innovation, by Gregory F. Nemet.

• Author: Bistline, John

How Solar Energy Became Cheap: A Model for Low-Carbon Innovation, by Gregory F. Nemet (Routledge, 2019). 260 pages, ISBN13: 978-0367136598.

The precipitous and persistent declines in solar photovoltaic (PV) costs have been one of the most notable developments in the energy landscape. Now one of the cheapest ways to generate electricity, solar's costs have fallen from $300,000/MWh in its first commercial use in 1957 to about $20/MWh today. Almost as remarkable as solar's technological success are the failures to forecast the pace and extent of these developments over the last decade. For instance, prices for solar contracts signed in 2017 are already below optimistic expert forecasts for 2030 in elicitations conducted between 2008 and 2015, which illustrates not only the tendency to overestimate solar costs but also the limits of forecasting (Reed, et al., 2019; Creutzig, et al., 2017; Craig, et al., 2002).

Despite these striking trends, questions about how solar became inexpensive have remained largely unanswered. There has been disagreement about the relative importance of scale economies, learning-by-doing, policy support, and R&D in cost declines. Since solar is only 1-2% of global electricity supply, understanding the drivers of its historical development could shed light on solar's future. These lessons could also help to direct and accelerate the technological progress of other low-carbon options, because addressing climate change requires significant transformations in the energy system.

Gregory F. Nemet's book How Solar Energy Became Cheap: A Model for Low-Carbon Innovation provides a comprehensive assessment of solar's cost declines and synthesizes a wide range of scholarship. The book aims not only to provide an answer to how solar became inexpensive but also to explain why it took so long and how PV could serve as a model for other technologies. The research is based on over 70 personal interviews and quantitative work in peer-reviewed publications by Nemet and others. Familiarity with this literature is not required for readers of the book, but the additional detail complements Nemet's summaries and the well-referenced text points motivated readers to further material.

The book's core argument is that inexpensive solar evolved from a ".. .sequence of disparate activities over the past 70 years that involved strong global links, important local activities, and the participation of multiple governments, firms, and influential...