Krastorio 2 Greenhouse + Wood Pyrolysis
Note on v1.7.0: By default, greenhouse output rates no longer benefit from higher tiers of quality! It can be re-enabled in the settings, though.
Overview
The mod first and foremost provides a greenhouse for easily growing wood, pyrolysis tech for converting wood into coal and oil, plus early access to Coal Liquefaction. The wood pyrolysis recipes are meant to mimic real-life pyrolysis, which may produce varying amounts and qualities of oils, gasses and solid char through either carbonization or destructive distillation of carbonic material. The mod has a purpose that is fairly similar to that of the Wood Gasification mod, but it aims to be as simple and integrated with existing processes as possible, while still providing a unique challenge.
In Space Age, tree seeds can be obtained as soon as the greenhouse tech is unlocked (and extracted at half the cost and twice the speed), and 4 greenhouse variants for Gleba crops can eventually be unlocked as well (they may produce yumako fruits, jellynuts, stone/spoilage or spoilage; all of them are restricted to being built on Gleba only). As of v1.5.0, a slightly different kind of wood distillation can be performed in the biochamber as well, for the sake of end-game balancing.
Notes on wood pyrolysis
Wood carbonization is suitable for producing large amounts of coal without byproducts or more heavy oil for lubricant, but wood distillation is slightly more efficient in general and is particularly useful when it comes to all the petroleum-derived products, which are needed in bulk. Having several outputs, the latter recipe certainly makes the overall process harder to manage, and optimal production requires simultaneous use of advanced oil processing and coal liquefaction, but in return, roughly 24% more petroleum gas can be obtained from the same input, with less power and with a smaller factory footprint.
Coal can clog up oil production early on, even if only plastic is produced, so it must either be consumed by other processes (it could be used for steam power) or stockpiled. You will want to research Coal Liquefaction as soon as possible.
Notes on balancing
Steam power fueled by wood from greenhouses is very space efficient compared to solar power, but it does also pollute, so I think it's fine. Probably.
Making Coal Liquefaction available early is perhaps overpowered, but the mod can already circumvent the use of oil wells, and mining and liquefying coal before large productivity gains have been acquired is a trade-off. And if wood can be converted to oil, why not coal! The process naturally completes the mod.
The outputs derived from Gleba crops compared to the trees of Nauvis are enormous. A yumako tree yields 25 times as much fruit as a normal tree yields wood, but even if that difference is reduced to just a factor of 2 with the greenhouses from this mod, 9.8 + 1.6 yumako fruit & jellynut greenhouses (still only roughly double that when comparing chains with max. productivity) may still provide for as much plastic production as 100 wood greenhouses do. Not to mention that burning the output of a single jellystem can provide up to a hundred times the power of a solar panel. Space Age just has ridiculous balancing like that.
With Quality, and with modules enabled, the greenhouses can be used to directly produce quality wood! In Space Age, that would also include quality Yumako, Jellynut, stone and spoilage. Note that, as of v1.7.0, greenhouses do not benefit from higher quality tiers by default! This is for the sake of parity with agricultural towers which cannot benefit from it either.
Mod integration & recommendations
The mod provides its own glass for the greenhouses by default, but it may be provided by other mods instead, specifically Krastorio 2, AAI Industry, Bob's Metals, Chemicals and Intermediates (with adaptation for Angel's Smelting), Factorio+, Crushing Industry, QuirkyCat Glass or Glass. An Electric Boiler makes setups with Coal Liquefaction a bit neater, while potentially saving on coal. A Water pumpjack or Stone Water Well provides easy access to water in arid locations. Valves can make it easier to manage oil production (especially the coal liquefaction heavy oil loop), and so may a Flare Stack. Perhaps you will like the Color Coded Pipes used in the screenshots above as well.
Licensing & credits
The mod is released under the same GNU LGPLv3 license as Krastorio 2 by raiguard, which it borrows graphical assets from. Those assets are all the greenhouse-related .png-files in the assets folder, except my recolored derivatives and the custom remnants. The sand and glass graphics are borrowed from Glass by GotLag.