The book is no more than ~15 years old, and may have been reviewed on Boing Boing.
Set far in the future, civilizations on rogue planets in interstellar space (or perhaps orbiting brown dwarfs?) have evolved a form of social organization where people cope with lower energy (lack of bright yellow stars) by having machinery accumulate solar power and resources for decades or centuries, then people wake up, the cities are warmed, etc.
This goes on for tens of thousands or hundreds of thousands of years, while "fast" civilizations rise and collapse around the warm stars.