While plenty of evidence suggests the progress away from fossil fuels is still too slow, wind and solar energy have sustained growth and are contributing to efforts to decarbonize electricity around the world. According to Bloomberg New Energy Finance, 2018 witnessed global wind and solar installations surpass the one-terawatt threshold. Innovative solutions to climate and air pollution, while increasing the overall supply to electrify automobiles and homes for those without energy access, will be multi-faceted and complex. But whatever suite of technologies or organizational forms decarbonization efforts take, renewable and solar energy will play a leading role in the energy futures. How did the renewable energy industries achieve such rapid and widespread success in recent years? How can this success be sustained to achieve high levels of low carbon electricity?

I was delighted for the opportunity to review two quite excellent explorations of renewable energy transitions that are creating quite a buzz since publication in early 2018. The topic of energy transitions is of increasing interest because of growing attention to strategies for deep decarbonization of the economy. There are many experts offering valuable perspectives on important decisions that will shape future energy pathways. Should resources be invested in deploying technologies that are available today, or should scarce funds be directed at research and development? What are the social and technical obstacles to overcome with energy transitions? I looked forward to thinking about these questions through the ideas and arguments presented in these two books.