THE CORES
"THE HEARTS OF THE GODDESSES"
the core generators were made purely out of desperation, but their birth came long before the death of the sun. They were, in a way, a great potential merely waiting for the opportunity, a backup should the needs for energy ever shift. No one expected their fruition to be the result of something so drastic.
Invented by Dr. Weilan Gara, the generators operate through a complex geothermal system within the planet's crust. Kepla was the prime planet for the cores, as it is bountiful with magma chambers throughout the lower strata of the crust, leaving the water table and aquifers throughout the land very warm, so geothermal energy was an immense benefit for the freezing planet. Jhone and Yona, with fewer magma chambers, still have their core generators as a major source of energy, but have other sources providing assistance: Jhone has the moonfarm system, and Yona has a small hydrokinetic/hydroelectric system via its many canals and hypocausts.
While the generators are not actually the core of the planets, they are colloquially referred to as such due to how far below the surface it is. The generator is actually a series of layers within the crust that feed off of magma pockets and the heat they produce. There are three main parts to the generator. The first is the magma chamber, which can be a simple pocket of magma or an aquifer/well of water heated by magma-heated rock. Whatever the case, injection wells are drilled into the chamber so that the contents can be brought closer to the turbine layer. The turbine layer, located above the main magma chamber, is moved by the rising steam produced by the magma, which generates the energy and warmth for the planet to survive. A third layer, the mechanical layer, is used for upkeep, engineering, and so on. Some workers use it to get from place to place without having to leave the core.
On Kepla, the geothermal generator has brought a sense of peace back to its people, though fragile and susceptible to malfunctioning at any given notice. Its upkeep has been a struggle lately, even with the empress's adamance that it be taken care of at all times, because of the absence of its creator. In his life, Gara was insistent that he handled the intricacies of the machine, ultimately dooming it when he disappeared. Aside from occasional blackouts and surges, its operation is still adequate enough to keep Kepla alive.
Jhone mainly uses the core to heat farmland. Keeping the land warm prevents it from freezing and killing crops, and combined with Keplan prehistoric genetic alteration of fauna, the solar death has not impeded crop harvest in recent years. When the goddess planets were being colonized, scientists genetically altered significant crops to be hardier, and recent adaptation is already occurring with no photosynthesis at play. Keeping the ground warm has helped this further.
Yona's use of the geothermal core is primarily for the hypocausts just underneath the surface. Steam is filtered from the core to warm floors all over the planet, which alleviates the amount of energy needed to warm many homes. Yona's core occasionally gets overloaded by the energy requirements that a megalopolis demands. Its common for power outages to occur.
The cores serve not only as a resource but as a beacon of hope for Keplans inter-globally. They came at a time of massive panic, in the midst of a seemingly ceaseless war that would wipe everyone out, and brought warmth back to darkness.