Kort Crystals

These roughly human-forearm-sized crystals are capable of storing electrical energy for several months or years at a time, functioning essentially as batteries that power most of the high-tech systems in Kort. They are, coincidentally, made from a specific type of quartz found only near the gnomish city. The engineers and arcanists in the city fit each crystal with metal terminals, then use machines or their own magical ability to pump lightning into the crystal. After a short cooling period of a few hours, the crystals can be stored in any container and hold their charge for up to a year each.
The discovery of the crystals and the process to charge them happened in 1269 2A, though it did not become widespread or mass produced for at least two decades, as the crafters and artificers initially rejected the new technology. The major taking off point for the crystals was around a year after the Tribrenen became the official rulers of the city, just before 1300 2A. They recognized the potential for innovation and advancement the crystals presented, and they directed some of the city's funds to go to the discovering firm as a loan to build a large production facility that would help lead to breakthroughs in the city.
In current times, the batteries are mass produced and power a great many systems and machines in Kort. However, they are not so commonplace that the city's commoners own them for their personal households. Many Korters have seen the crystal batteries, and a large portion of the city have probably handled one at some time, but they are not things that the common person interacts with daily, other than using the machines they power.
Once plugged in to a machine, the electrical charge in each battery holds for up to two years - allowing advanced production to anticipate needs three years in the future (accounting for up to a year of storage before use). Once this charge ends, the crystal can still conduct some amount of electricity, though it is no longer reliable enough for the city's machines. Most are sent to reprocessing plants where they are ground to a fine powder and enchanted as part of high-tech jewelry or fashion. In this ground up state, the crystals can hold enchantments indefinitely - or at least, none have expired in the 170-plus years since this recycling practice started.

Utility

A recent discovery of arcane power has led to the creation of much smaller Kort Crystals that can enchant or power weapons for the defense of Kort. The typical crushed and powdered crystals that can hold enchantments indefinitely can be molded into smaller, finger-sized batteries to run electric current along a sword blade or cause a rifle to shoot beams of energy instead of bullets. Because they are made of the crushed crystals which have enchantments placed into them, these weapon batteries do not have to be replaced, and many are housed or forged right into the design of the weapons themselves. Because Kort does not maintain a standing army, there are not many of these weapons available, except to the small force of Watch members who keep the peace and repel occasional invasions or roaming beasts.