How dye-sensitized solar cells, which are lightweight, bendable, and manufactured cheaply, can capture light indoors to charge small gadgets like headphones (Christopher Mims/Wall Street Journal)

Christopher Mims / Wall Street Journal:
How dye-sensitized solar cells, which are lightweight, bendable, and manufactured cheaply, can capture light indoors to charge small gadgets like headphones  —  Indoor solar power technology is finally becoming available; Some devices no longer need batteries at all