The Windup Girl by Paolo Bacigalupi is an excellent novel set in a future in which "carbon fuel sources have become depleted, and manually wound springs are use

The Windup Girl by Paolo Bacigalupi is an excellent novel set in a future in which "carbon fuel sources have become depleted, and manually wound springs are used as energy storage devices [0]." There are also genetically-engineered animals that are particularly strong and good at converting food calories into kinetic energy (for winding storage springs or other uses) and treadle-powered desktop computers [1], like sewing machines before electricity. [0] https://en.wikipedia.org/wiki/The_Windup_Girl https://en.wikipedia.org/wiki/The_Windup_Girl [1] https://en.wikipedia.org/wiki/Treadle https://en.wikipedia.org/wiki/Treadle