Nauvis has been sitting on free energy all along. Geothermal steam fissures now spawn across the map, always clustered near ore fields, waiting to be tapped. With Space Age, they follow you to Gleba, Fulgora and Aquilo.

Features

Geothermal fissure infinite geothermal steam sources that spawn near ore patches. Not every deposit gets them: finding a rich field is a small jackpot, and richness scales with distance from spawn like oil.

Geothermal pump an early-game extractor (cheap tech, right after steam power) that sits on a geothermal fissure and outputs 165°C steam. Pipe it straight into steam engines: fuel-free, grid-independent, and far cleaner than coal boilers.
Perfect for powering mining outposts on-site.

Geothermal pressurizer the mid-game upgrade: boosts geothermal steam to 500°C
and unlocks steam turbines before nuclear. One pressurizer feeds 4 turbines (23 MW) but draws 5.8 MW itself. Plan an independent power supply, or face the brownout death spiral.

Coal distillation no oil field in sight? Distill coal with geothermal steam into synthetic crude oil (the classic 1.0 refinery makes its comeback).
Deliberately much less efficient than vanilla coal liquefaction, and it produces waste (depleted steam, sludge) you will need to flare off. Your first distilled crude oild unlocks vanilla oil processing, both routes converge into the normal tech tree.

Space Age

Fissures spawn on three more planets, anchored on whatever that world actually has:
- stone on Gleba
- scrap on Fulgora
- crude oil, lithium brine and fluorine vents on Aquilo.
Vulcanus is deliberately left out, it already has its acid geysers.

Water on Fulgora a technology unlocks the vanilla steam condensation recipe without a detour through Vulcanus, so a fissure becomes a water source. Condensing is never free though: every unit of steam you turn into water is a unit that no longer feeds your steam engines.

Geothermal heat exchanger on Aquilo, turns fissure steam into heat for heat pipes with no fuel at all. Output scales with steam temperature, so it already runs on the 165°C steam coming straight out of a pump, enough to thaw a base the moment the rocket lands.
Pressurized 500°C steam yields over three times more energy per unit, making the pressurizer an upgrade rather than a prerequisite. Like the vanilla heating tower, neither it nor the pump ever freezes, everything else on your base still does.

Aquilo fissures are rarer but far richer than elsewhere, and in practice they concentrate on the landing island, where a field is guaranteed. That is exactly where geothermal earns its keep: it is the island you have to make liveable before anything else. Space is scarce on the ice and the exchanger is hungry, so heating and generating power both eat into the same handful of fissures.

Settings

Geothermal fissure frequency, size, richness and distance scaling are configurable, plus a per-planet toggle (runtime settings, applied to newly explored chunks).

Adding it to an existing save

Safe to add mid-game. Fissures are placed as chunks are generated, so they appear in land you have not explored yet - and on any planet you have not landed on. Areas already revealed stay as they are, which usually means your home base keeps its current layout while every new outpost gets the option.

Dependencies

Flare Stack to destroy distillation waste.

Credits
- classic beacon, 1.1 refinery and nuclear reactor pipework artwork by Wube Software
- pressurizer and heat exchanger artwork AI-generated and hand-cleaned.
- original ideas https://mods.factorio.com/mod/Geothermal https://mods.factorio.com/mod/Geothermals