Grinspoon speculated that life on Titan, if there is any, might be able to produce energy by mixing acetylene, a hydrocarbon abundant in Titan's atmosphere, with hydrogen. The energy could then be harnessed to power metabolism or to heat their surroundings.
"In environments that are energy-rich but liquid-poor, like near the surface of Titan, natural selection may favor organisms that use their metabolic heat to melt their own watering holes," Grinspoon said.
Which reminds me: Why the hell did I set aside Grinspoon's "Lonely Planets"? He had enough smart things to say about exobiology that I was willing to forgive his rote Face on Mars dismissal.