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Organic Farming & Biomass Design

Document Type: Design Document Version: 0.1 (Draft) Status: In Progress Last Updated: 2026-08-27 Vault destination: 01_Design Documents Amends: 26_Pollution, Waste & Organic Systems Design §7 (Organic Farming), 25_Power System Design §5.1 (Biomass Burner fuel) Resolves: OI-247 Related: [26_Pollution, Waste & Organic Systems Design](<./26_Pollution, Waste & Organic Systems Design.md>) · [04_Factory & Resource System Design](<./04_Factory & Resource System Design.md>) · [25_Power System Design](<./25_Power System Design.md>) · [24_Module System Design](<./24_Module System Design.md>) · [23_Port System Design](<./23_Port System Design.md>) · [22_Trains & Rail](<./22_Trains & Rail.md>)

1. Summary

Cultivated organics as the renewable counterweight to extraction. Two production families (biomass and algae), both built from a Control Hut plus Bays pattern, both feeding chains that already exist.

This document is smaller than OI-247 anticipated. The register recorded the organic chain as entirely missing. Most of it was already present under a different name.

2. The Correction: raw_biomass Already Exists

Pollution §7 promised three crops. Checked against the resource list in 04_Factory, two of them duplicate a resource that has existed since Phase 1 was written.

Promised crop Promised output Actual status
Bio-polymer crops Organic carbon → Polymer Sheet Already exists. ref_polymer = raw_biomass + Chemical Gas, at the Chemical Plant
Fast-growth timber Wood → Biomass Burner Naming drift. The building is the Biomass Burner. Its fuel is biomass
Algae Biofuel → Fuel Generator Genuinely new. The only new chain in this document

raw_biomass is already load-bearing. Polymer Sheets feed Hull Plating, Energy Conduit and the Advanced Science Drive, so biomass sits on the critical path to Milestone 1 today.

⚠️ 25_Power System Design §5.1 states the Biomass Burner runs on "Wood (solid belt)". No such resource was ever defined, and none is needed. The entry is a naming error, not a missing design. Correct it to raw_biomass.

2.1 Three resources are deleted, not defined

raw_wood, "organic carbon" and "bio-polymer crops" are removed from the design. Each was invented in prose to describe something raw_biomass already does. Defining them would have created three resources, three icons, three recipes and three research nodes for no mechanical gain.

This is the second time a document asserting something exists has stopped anyone checking whether it did (see the Geothermal Tap and Core Power Station note in 04_Factory). Recorded rather than repeated.

3. Two Buildings, One Pattern

3.1 Control Hut plus Bays

Both farm families use the same composition:

Family Head Extension
Biomass Farm Control Hut Greenhouse Bay
Algae Farm Pond Head Pond Bay

The head is an ordinary building: standard base, ports, base ring, module slots, power connection, crop selection, name. The bays are the field.

This is the Station Head plus Freight Platform pattern from 22_Trains & Rail §4, and the area-based model already used by power poles. The player learns one composition rule and it transfers across three systems.

3.2 Bays are extensions, not buildings

Locked: a bay has no ports, no module slots and no base ring.

Module slot count is derived from footprint (24_Module System Design §2.2), so a bay built as an ordinary building would carry at least one slot. A six-bay farm would then hold seven slots for one production unit, making farms the most module-dense structure in the game by a wide margin and inverting the whole slot economy.

Extensions avoid this without exception-casing the slot rule. Every building still has at least one slot from the moment it is placed. A bay is not a building.

It also keeps the port model clean: one head, one set of ports, one place the Router feeds.

3.3 This applies to trains as well

⚠️ 22_Trains & Rail §4 currently describes Freight Platforms as ordinary buildings with donut bases and ports. Under §2.2 that gives a four-wagon station five module slots. The same reasoning applies: platforms should be extensions of the Station Head, not buildings.

That was never examined because trains were designed before this pattern had a second instance. Tracked as a follow-up.

4. Wild versus Cultivated

Both produce the identical item, raw_biomass. They differ in economics, not output.

Biomass Harvester (wild) Biomass Farm (cultivated)
Source node_biomass patches Built anywhere with inputs
Supply Slow and infinite Scales with bays
Rate Fixed, low High
Land Wherever nodes happen to be Player-chosen, large
Inputs None Water, fertiliser, light, power
Role Permanent trickle Volume

The Harvester is never outgrown, it is outscaled. It stays cheap, needs no research and feeds the player's first Polymer Sheets in the opening hours. The Farm arrives when Hull Plating and Advanced Science Drives push demand past what a trickle can carry.

This is a better arc than obsolescence, and it avoids the usual pattern where an early building becomes a dead entry in the build menu.

5. Inputs

Requirements vary by crop. The Control Hut holds the recipe; the bays supply the area.

Input Delivered via Notes
Water Pipe, to the head Baseline for both families
Fertiliser Belt, to the head Recovered from recycled organic waste. Closes a loop (Pollution §7.2)
Light Ambient, or artificial Reduced by air pollution (Pollution §2)
Air OPEN, see §5.2 Greenhouse only
Power Grid Climate control, circulation, lighting if fitted

5.1 Artificial lighting is allowed

Greenhouses may run artificial lighting, trading power for independence from ambient light.

This deliberately gives the player a way out of the smog trap in Pollution §2, and the way out costs power. If that power comes from Coal Generators, the smog thickens and the lighting bill rises with it. The trap still closes; it just closes through the power system instead of directly.

Same shape as the electric locomotive argument (22_Trains & Rail §3.2): the escape is real, and it is only as clean as the grid behind it.

5.2 The air input is open

Greenhouses consuming an air input is a good loop, since combustion produces exactly what plants want. Two shapes, and they are not equivalent:

Option Shape Cost
Zonal Greenhouse near emitters gets a yield bonus from local air pollution Free to build, but fights §2 by making smog locally good. Confusing
Piped A capture building on generator exhaust produces a fluid, piped to greenhouses One building, one fluid. Explicit, physical, gives generators an output port

Recommendation: piped. It makes the loop something the player builds rather than something that happens invisibly, and it avoids the contradiction of smog improving yields. It also does not duplicate the Air Scrubber (Pollution §3a.3): the Scrubber neutralises, capture uses. That distinction is the whole recycling philosophy in miniature.

Tracked as an open item.

6. Algae

The one genuinely new chain.

Pond Head + Pond Bays  →  Algae  →  Biofuel  →  Fuel Generator

Algae is water-surface rather than land, which gives it a distinct silhouette from above and a distinct siting constraint. It competes with the Biomass Farm for water, not for land.

Its output feeds the Fuel Generator, giving that building a renewable fuel path alongside its fossil one, and mirroring the biomass-to-Biomass-Burner relationship exactly.

Open: whether Algae is a distinct resource or whether the Pond produces fld_fuel directly via an intermediate.

7. The Zero-Pollution Planet

Design goal: a player should be able to run a planet at zero pollution through recycling and reuse. Not merely low, zero.

This is the constructive counterpart to Restoration (Pollution §7.4). Restoration cleans up someone else's damage; this is never doing the damage in the first place.

7.1 Capture reduces. Only stopping combustion eliminates

⚠️ Guard rail: flue capture must never reach 100%. An instance of Canonical Design Facts §12b — closed loops are always lossy.

If capture could fully close the loop, a player could burn coal forever at zero net pollution, and the entire dirty-versus-clean axis would collapse into a plumbing puzzle solved once.

Capture reduces emissions while you still burn. Reaching zero requires not burning. That means clean primary generation: Solar, Wind, Geothermal, Core Power. Those already exist and already have the right properties.

The reward for a fully closed loop is therefore earned by changing what you burn, not by out-plumbing the consequences. That is both physically honest and the better goal to give a player.

7.2 The clean path costs land, power and throughput, never impossibility

Same guard rail shape as the Incinerator's heat recovery (20_Belt Logistics - The Router §3b.2). The closed loop must be:

  • Achievable, or the goal is a lie
  • Slower and more land-hungry than the dirty path, or the dirty path has no reason to exist
  • Sustainable indefinitely, which is the thing the dirty path cannot offer

Fossil is fast, compact and finite. Organic is slow, sprawling and endless. Both stay legitimate.

7.3 What this gives Tab 7

A pollution readout that can genuinely reach zero is a target, not just a warning light. It makes the Pollution tab (HUD Pollution Tab Specification) something a player works toward rather than something they glance at when the base ring goes amber.

8. What This Touches

System Impact
04_Factory Resource List Add Algae and Biofuel. No Wood, organic carbon or bio-polymer crop
04_Factory Power Buildings Correct Biomass Burner fuel to raw_biomass
25_Power System Design §5.1 Same correction
Pollution §7 Rewrite to match this document. Three crops become two families
Pollution §3a.4 Soil Remediation's organic input is now defined: it consumes biomass
22_Trains & Rail §4 Freight Platforms become extensions, not buildings (§3.3)
24_Module System Design No change. The extension pattern preserves §2.2 rather than excepting it
08_Research Tree Design Branch 9 Environmental can now be written (OI-248 unblocks)
05_Asset List Four new assets: Control Hut, Greenhouse Bay, Pond Head, Pond Bay. Footprints still needed

Open items for this document are tracked in docs/open-items.md, area farming.

9. Revision History

Version Date Changes
0.1 2026-08-27 Initial draft. Corrected the biomass duplication, deleted three invented resources, established Control Hut plus Bays for both families, bays as extensions, wild slow-and-infinite versus cultivated volume, artificial lighting allowed, zero-pollution planet as a design goal with the capture guard rail.