Star Trek: 10 Things You Didn't Know About Warp Drive
5. One Crystal To Rule Them All
Dilithium Crystals were the main source of powering the Warp Cores of Starfleet ships, along with many other races in the galaxy. The Klingons, Cardassians and the Breen all sought these rare minerals for their propulsion systems. Much like the fossil fuel crisis that Earth faces today, these were a finite resource, leading to raiding parties and trouble between powers.
By the 2250s, Starfleet was already aware of the dwindling supplies, though it would not become acutely critical until the 31st century. Experiments in spore drive technology were initiated in the hope of replacing the crystals, though they were deemed a failure. Another issue facing them was that through a process known as decrystallisation, they would effectively run out of power. Spock and Scotty managed to devise a way to recharge them during a temporal mission in 2286, which was then implemented through the rest of the fleet by the 24th century.
The discovery of a planet made of dilithium in the Verubian nebula may have served to help Starfleet get back on its feet by the 32nd century, though many more experiments in alternative forms of travel were badly needed to replace this dwindling supply.