That is the topic of my latest Bloomberg column, here is one excerpt:
The first disquieting sign is that solar companies are spending only about 1 percent of their revenue on research and development, well below average for a potentially major industry. You might think that’s because things are going so great, but some major solar users may have already maxed out their technology. According to Sivaram’s estimates, four of the five most significant country users — Italy, Greece, Germany and Spain — have already seen solar energy flatten out in the range of 5 percent to 10 percent of total energy use. The fifth country, Japan, is only at 5 percent.
A common view is that solar power will come into its own once batteries and other storage technologies make steady improvements. Yet Sivaram notes that lithium-ion batteries in particular are not well-designed for storage across days, weeks and months. Also note that about 95 percent of global energy storage capacity is from hydroelectric power, a discouraging sign for the notion that solar energy storage is on a satisfactory track.
Solar energy has great potential for emerging economies, but some very basic preconditions are not in place. India, for instance, would need to end its kerosene and electricity subsidies. Freer trade in solar technologies is found in Tanzania and Rwanda but not always in West Africa.
My column draws heavily on Varun Sivaram’s forthcoming Taming the Sun: Innovations to Harness Solar Energy and Power the Planet, Amazon link here. This book is full of useful information, a pleasure to read, and more generally a model for how to write about science, technology, and policy. It will definitely make my 2018 “best books of the year” list.