Most Fulgora guides tell you to “recycle scrap and get resources.” None of them show you the probability table — the actual numbers that determine how much of each item your recyclers produce per scrap unit. Without the table, players routinely build holmium chains at a fraction of the capacity they need, then hit a wall when supercapacitor output is constrained by the 1% ore drop rate sitting underneath everything.
This guide leads with the complete probability table, then covers the mechanics that follow from it: accumulator buffer sizing for the lightning storm cycle, the Electromagnetic plant’s +50% productivity advantage, the full holmium-to-supercapacitor chain, and the quality cascade trick that turns surplus scrap runs into rare and epic components for free.
If you have the Factorio Space Age Beginner’s Guide under your belt and are ready to land on Fulgora, this is what you need. If you are already there and your recycler keeps stalling, start with the probability table — the answer is almost certainly in row six.
Quick Start: Your 10-Step Fulgora Setup
Here is the full setup sequence. Detailed explanations follow each step below — but if you need the roadmap before you land, here it is:
- Land with at minimum 1,200 steel plates, 400 processing units, 50 accumulators, and 20 lightning rods
- Place lightning rods before your first nightfall — one rod every 12 tiles covers your landing area adequately
- Find and mine the nearest Fulgoran vault ruin by hand to unlock the Recycler building and the scrap recycling recipe
- Deploy 20+ electric mining drills on the closest scrap patch
- Build a 10-recycler array — this saturates exactly one yellow belt of scrap input
- Sort recycler output by item type; immediately loop concrete, stone, and surplus iron gear wheels into a destruction recycler bank
- Research Holmium Processing as your first Fulgora technology priority
- Set up a chemical plant fed by offshore pumps (heavy oil) and melted ice (water) to produce holmium solution
- Unlock and build your first Electromagnetic plant — run all advanced electronics through it for the built-in +50% productivity
- Produce Electromagnetic science packs and launch them back to Nauvis
Verified on Factorio Space Age 2.0. Values may change with updates from Wube Software.
Before You Land: The Vulcanus Advantage
Fulgora has no fossil fuels and virtually no solar power — solar panels output only 20% of their Nauvis value due to orbital distance. Lightning is your power source from the first minute. Players who complete Vulcanus first arrive with two genuine advantages: surplus steel from cheap molten iron and copper, and productivity module research already in queue. Both pay off immediately on Fulgora.
Minimum landing kit:
- 1,200 steel plates — rails, lightning rods, assembler frames, and the first wave of electric poles all consume steel fast
- 400 processing units — tech cards run out before your recycler loop is producing usable outputs at scale
- 50 standard accumulators — buffer against the first storm while your lightning rod network is still thin
- 20 lightning rods — deploy these on landing, before you build anything else
- 200+ belt sections and 20+ electric mining drills
- Extra electric poles and power cabling — bring more than you think you need; your base will sprawl
The Vulcanus Foundry is worth unlocking before you visit Fulgora. It gives a built-in productivity bonus to metal processing including holmium plates — which you will be producing on Fulgora within an hour of landing. The Factorio Vulcanus Guide covers the full Foundry unlock path. The Factorio Quality System guide is also worth reviewing before activating quality modules in your recyclers. Once Fulgora is operational, the Factorio Gleba Guide covers the next planet in the Space Age sequence.
Fulgoran Ruins: Your First Scrap Source and the Hidden Unlock
The most common early mistake on Fulgora is building before exploring. Fulgoran vault ruins are scattered across every island, and the first one you find contains something essential: mining it by hand drops the technology card that unlocks both the Recycler building and the scrap recycling recipe. Without that card, your recyclers sit empty producing nothing, regardless of how much scrap you feed them.
Mining the ruin requires no tool — walk up and hit it manually, the same way you mine an ore node by hand. It is a destructible entity, not a chest.
After the unlock, your island exploration loop is:
- Use radar to identify island types — small islands have dense scrap patches and limited build space; large islands have minimal scrap but room for a proper factory
- Deploy electric mining drills on small-island scrap patches as your raw material input
- Lay elevated rail across the oil-lake surfaces to connect islands — standard rail cannot be placed on oil without landfill, and elevated rail bypasses this entirely
- Run train loops ferrying scrap from extraction islands to your main factory island
The oil surface itself is a resource. Offshore pumps placed at the coastline produce heavy oil, which becomes rocket fuel and electrolyte — two ingredients your Fulgora factory needs constantly.
The Scrap Recycler Probability Table: The Data Most Players Get Wrong
Every scrap unit recycled rolls against a probability table. The table has 12 outputs and a combined probability of exactly 60% — not 100%. A fully loaded belt of scrap through recyclers produces an output belt that is on average 60% full, spread across 12 different item types. Builders who design their downstream production assuming 100% output density constantly run into belt starvation. The actual output is 40% less than expected before a single iron plate has been processed.
Here is the complete table, ordered by probability:
| Output Item | Probability | Per 100 Scrap | Action |
|---|---|---|---|
| Iron gear wheel | 20% | 20 items | Abundant surplus — convert to iron chests for 8× destruction speedup or smelt back to iron plates |
| Solid fuel | 7% | 7 items | Combine with light oil for rocket fuel; always useful |
| Concrete | 6% | 6 items | Use what you need; convert surplus to hazard concrete for 6.25× faster destruction |
| Ice | 5% | 5 items | Melt to water for holmium solution and offshore pump circuits |
| Stone | 4% | 4 items | Convert to landfill (10.4× destruction speedup) if surplus |
| Steel plate | 4% | 4 items | Critical bottleneck — raw recycling clears only 0.375 steel/s; craft into steel chests for 40× throughput |
| Battery | 4% | 4 items | Feeds the supercapacitor recipe directly; use it, do not trash it |
| Copper cable | 3% | 3 items | Route to circuit production |
| Advanced circuit | 3% | 3 items | Use in EM science packs; surplus → recycle for electronic circuits |
| Processing unit | 2% | 2 items | High value — route to quality cascade if quality modules are active |
| Low density structure | 1% | 1 item | Rocket construction material; export to Nauvis |
| Holmium ore | 1% | 1 item | The hard bottleneck — every supercapacitor traces back to this 1% drop |
The consequences of the 1% holmium row are worth emphasising. One recycler processing 2.5 scrap per second produces 0.025 holmium ore per second. Building one supercapacitor requires 2 holmium plates, each plate needs 20 holmium solution, and each solution batch uses 2 holmium ore — totalling 0.8 holmium ore per supercapacitor. At 0.025 ore per second per recycler, a single recycler can support roughly one supercapacitor every 32 seconds. One EM science pack per second requires approximately 40 recyclers running continuously, purely from the holmium constraint.
Scale your recycler count to the holmium number you need, not to the iron gear wheel output. Everything else is surplus you can destroy.
Building the Core Recycler Loop
The structural challenge on Fulgora is item imbalance. The scrap table produces iron gear wheels at 20% and holmium ore at 1% — a 20:1 ratio. If any item’s output belt fills and backs up, the recycler that produced it stops entirely. That halts the whole array, including the holmium you actually need.
A functional loop has two stages:
Stage 1 — Primary sort: High-value outputs (batteries, copper cable, advanced circuits, processing units, holmium ore, low density structures) route to dedicated production belts. Medium-value surplus (iron gear wheels, solid fuel, concrete, stone, steel) routes to a secondary disposal belt.
Stage 2 — Destruction loop: The secondary belt feeds a bank of recyclers running in loop mode — output feeds back to input. Items without a recyclable recipe are destroyed at 25% per pass and self-eliminate over several cycles. Items with recyclable recipes continue breaking down. Steel is the dangerous exception.
The steel chest trick: Steel plates at 4% output accumulate faster than raw recycling can handle. A raw recycler destroys only 0.375 steel plates per second per cycle. A single assembler converting steel plates into steel chests removes 15 steel per second — a 40× improvement. Add one steel-to-chest assembler to your destruction loop and the steel backlog clears within minutes of startup.
Apply the same principle wherever you see belts filling: stone to landfill (10.4×), concrete to hazard concrete (6.25×), iron to iron chests (8×). When something backs up, the fastest fix is almost always “construct a bigger item before you trash it.”
Buffer holmium ore in a chest rather than routing it straight to the chemical plant. Early output will be intermittent. A chest absorbs the trickle and keeps the holmium chain running when ore rate varies between strikes.
Lightning Power: Rods, Collectors, and Accumulator Buffer Sizing
Your power system on Fulgora has two failure modes: no lightning structures and no accumulators. Players who build one without the other hit a wall on the first quiet period between storms.
Lightning rods and collectors harvest strikes and inject energy directly into the local electrical network. Their efficiency and storage capacity differ significantly:
| Structure | Efficiency | Storage Capacity | Legendary Efficiency | When to Build |
|---|---|---|---|---|
| Lightning rod | 20% | 500 MJ | 50% | Immediately on landing; your only early-game power source |
| Lightning collector | 40% | 1 GJ | 100% | Once supercapacitors are flowing; requires 8 supercapacitors per collector |
A lightning rod captures energy from each strike at 20% efficiency with a 500 MJ internal storage. A lightning collector doubles both figures: 40% efficiency, 1 GJ capacity. At legendary quality, a collector reaches 100% efficiency — it captures the full energy of every strike it attracts. Legendary collectors also cover approximately three times the area of legendary rods (12,200 tiles² vs 4,417 tiles²). The priority system means structures with higher priority attract strikes before background entities do — collectors at 10,000 priority and rods at 1,000 pull strikes away from your factory buildings reliably.
Accumulator buffer sizing: Strikes cluster during Fulgora’s night phase within the approximate three-minute day/night cycle. Between storm pulses, your base draws purely from accumulated charge. Use this formula for a conservative early-game buffer:
(Base load in MW) × 300s ÷ 5 MJ per accumulator = minimum safe accumulator count
Example: a 10 MW base requires 10 × 300 ÷ 5 = 600 accumulators for a five-minute buffer. In practice, with 15–20 active lightning rods continuously replenishing charge through the night, 300–400 accumulators sustain a 10 MW base reliably. The formula gives the no-lightning floor — real operation sits above it, but sizing to the floor prevents catastrophic drain during unusual quiet periods.
The practical rule: expand your accumulator bank every time you expand production. Target 30–40 accumulators per MW of base load as a working ratio. Under-buffering causes total factory shutdown during low-strike periods — it is the single most common Fulgora failure mode.
The Electromagnetic Plant: +50% Productivity That Changes Your Electronics Strategy
The Electromagnetic plant is Fulgora’s exclusive production building and the most important unlock on the planet. Its built-in +50% productivity bonus applies to every recipe it runs — not just intermediate products like standard productivity modules. It carries five module slots, consumes 2 MW at full load, and operates at base crafting speed 2 (reaching speed 5 at legendary quality).
The strategic implication is immediate: every 10 advanced circuit recipes in an EM plant yield 15 circuits. Every 10 processing unit crafts yield 15 processing units. For a base where holmium is the scarce input, that 50% bonus translates directly to more science packs from the same ore draw. Running advanced electronics in a standard assembler on Fulgora is waste.
The EM plant also holds exclusive recipes that cannot be crafted anywhere else:
- Superconductors and supercapacitors
- Quantum processors
- Lightning collectors
- Electromagnetic science packs
None of these can be produced in an assembling machine. Building the EM plant is the prerequisite for Fulgora’s entire tech tree, including Tesla turrets, mech armor, and the science packs needed to progress on Nauvis.
Module strategy: Without a quality cascade running, fill empty module slots with Productivity Module 3 for maximum output per ingredient. Once quality modules are active in your recycler bank, consider adding quality modules to the EM plant itself — a legendary-quality supercapacitor is worth significantly more than eight normal-quality ones when you build legendary lightning collectors.
Holmium to Supercapacitor: The Full Production Chain
Holmium ore drops from the scrap recycler at 1% — the rarest output in the table. Every bottleneck in a mid-game Fulgora base traces back to not building enough recycler throughput early. Here is the full chain from ore to finished supercapacitor, with the constraint at each step:
| Step | Recipe | Building | Key Constraint |
|---|---|---|---|
| Ore → Solution | 2 holmium ore + 1 stone + 10 water → 100 holmium solution (10s) | Chemical plant | Water from melted ice (5% from scrap) or offshore pumps; stone from recycler (4%) |
| Solution → Plate | 20 holmium solution → 1 holmium plate (1s) | Assembler 2/3 or Foundry | Use Foundry for productivity bonus; holmium plate cannot be recycled back to its inputs once crafted |
| Plate → Supercapacitor | 2 holmium plates + 1 battery + 10 electrolyte + 4 electronic circuits + 2 superconductors → 1 supercapacitor (10s) | Electromagnetic plant (exclusive) | Superconductors are also EM-plant-exclusive; build two EM plants minimum — one for superconductors, one for supercapacitors |
Critical logistical constraint: holmium solution cannot be barreled. It is impossible to export liquid holmium to other planets by rocket. If a Nauvis production line needs holmium chemistry, you must ship holmium ore and build a chemical plant at the destination. This shapes the entire Fulgora export strategy: finished goods only, no liquid intermediates.
The Foundry versus assembler choice for holmium plates: the Foundry’s built-in productivity applies to holmium plate production, making it strictly better than an assembling machine if you have Vulcanus Foundry research unlocked. One Foundry replaces 1.5 assemblers in effective output per ore input.
Build order that avoids starvation: chemical plant first (ore to solution), then the plate assembler, then the EM plant for supercapacitors — in that order. Do not wait until holmium ore reaches triple digits in storage. Start the chain immediately with whatever ore you have. The chain takes time to prime, and the science pack queue stalls while it fills.
The Quality Cascade Trick: Turning Scrap Surplus into Rare Components
Recyclers accept quality modules but not productivity modules. This distinction creates a strategy that costs nothing in raw materials: install quality modules in a dedicated recycler bank, filter outputs by quality tier, and route normal-quality items to standard production while uncommon-quality and above go to quality-aware assembly lines.
The mechanics: each quality module adds a flat percentage chance that a crafted output rolls at a higher quality tier than the input. With two quality modules in a recycler, the quality upgrade probability reaches approximately 10% per craft. Stacking more modules past two returns diminishing gains — the effective cap sits around 10% per roll regardless of module density. Quality is not additive beyond that threshold.
The practical setup:
- Build a parallel quality recycler bank of 8–12 recyclers, separate from your main destruction-loop recyclers
- Add 2 quality modules to each quality recycler
- Tap a portion of the scrap belt input to the quality bank — do not redirect your entire scrap throughput
- Use circuit-network filters on output belts: normal items route to standard production or destruction; uncommon/rare/epic/legendary route to a quality chest
- Items exiting at normal quality with no production destination loop back into the quality recycler for another roll
The best targets for quality farming via recycler are processing units (2% base from scrap) and advanced circuits (3%). A rare processing unit in an EM plant with quality modules propagates quality to the science packs it builds. Legendary processing units sourced from scrap — while infrequent — cost nothing in additional resources beyond the scrap you were already recycling.
Throughput note: the quality recycle loop is slower than a straight destruction loop because items pass through multiple times. Run quality recyclers in parallel with your main array, never as a replacement. A 10-recycler main array plus an 8-recycler quality bank is the standard mid-game layout.
Common Fulgora Failure Points
Five problems account for most stalled Fulgora bases:
Under-buffered accumulators. The most prevalent failure. Players land with 50 accumulators, build a 15 MW factory, and never expand the buffer. A 20-minute quiet period between heavy storm cycles drains the bank and collapses production. Expand accumulators in proportion to every production expansion. The 30–40 per MW ratio is a floor, not a target.
Steel belt backlog. Steel at 4% output sounds modest until 30 recyclers are running. Without a dedicated steel-to-chest assembler on the destruction loop, the steel belt fills in minutes and halts the entire recycler array. Build the chest assembler before the belt is full, not after the factory has already stopped.
Skipping ruins exploration. Players who land, place mining drills, and start building discover their recyclers produce nothing because the scrap recycling recipe was never unlocked. Find and mine the vault ruin first. This takes two minutes and unlocks the core loop. There is no workaround.
Building the main factory on a small island. Small islands have dense scrap but almost no room to expand. A factory that starts on a small island will be constantly relocating assemblers and belts as the build grows. Set up extraction on small islands and connect via elevated rail to a large island for the main factory.
Ignoring the holmium chain until science packs are needed. Players who prioritise iron and copper production and defer holmium as a side task hit a wall when EM science packs are in queue but supercapacitors are metered at a trickle. The holmium chain takes time to prime. Set it up at the same time as your main recycler loop, even if the ore numbers look small at first.
What to Export Back to Nauvis
Fulgora is primarily an EM science factory, but several of its outputs are uniquely valuable on other planets:
- Electromagnetic science packs — the primary Fulgora export; required for Tier 4 research progression on Nauvis
- Holmium plates — needed for advanced module production on Nauvis; ship ore and plates, not solution (which cannot be barreled)
- Supercapacitors — used in portable fusion reactors, mech armor, and advanced power infrastructure
- Low density structures — at 1% from scrap, they accumulate steadily; export for rocket construction
- Advanced circuits and processing units — surplus from the recycler loop is essentially free; Nauvis always absorbs more
What not to export: holmium solution (cannot be barreled), raw scrap (no value off-planet), concrete (produced more cheaply on Nauvis), or solid fuel (plentiful everywhere). Prioritise items that Nauvis cannot produce locally or produces at significantly higher cost. Holmium plates and EM science packs are your primary payload; everything else is secondary fill.
Fulgora Guide by Player Type
| Player Type | First Priority | Biggest Risk | Strategy Shortcut |
|---|---|---|---|
| New player | Survive the first night: lightning rods and accumulator buffer before building anything else | Factory collapses during first power drought; panic over item imbalance on recycler output | Build 2× more accumulators than you think you need. The destruction loop handles item imbalance automatically once it is set up. |
| Casual player | Get the recycler loop and destruction loop functional, then leave it running while you explore islands | Steel backlog halting the entire recycler mid-session while you are away from base | The steel-to-chest assembler trick solves 80% of belt backup problems without circuit networks |
| Hardcore optimiser | Calculate exact holmium throughput required for your target science pack rate; back-fill recycler count from the 1% drop rate | Quality recyclers eating main-loop throughput if placed incorrectly | Run quality recyclers on a parallel tapped belt. Never replace main throughput recyclers with quality ones. |
| Completionist | Full radar coverage of all accessible islands before committing to a factory location; explore every ruin | Missing a ruin with a unique tech drop and backtracking after the factory is built | Deploy a roboport with construction bots from the first landing pack — ruins are spread across multiple islands and remote exploration is unavoidable |
Frequently Asked Questions
Why does my recycler keep stopping even though there is scrap on the input belt?
A recycler stops when any of its output item slots are full — not just the backed-up type. Every item in the scrap probability table shares the same recycler, so a full iron gear wheel belt halts holmium ore output too. The fix is a complete destruction loop covering every output type, especially iron gear wheels (20% output rate) and steel (4% but high accumulation speed). If you are only looping one or two output types, the others will eventually back up and freeze the entire array.
How many recyclers do I need for one EM science pack per second?
Work backward from holmium. One EM science pack requires one supercapacitor, which requires two holmium plates, which requires 40 holmium solution, which requires 0.8 holmium ore. At 1% probability per scrap unit with 2.5 scrap per second per recycler, one recycler produces 0.025 holmium ore per second — supporting approximately one supercapacitor every 32 seconds. For one EM science pack per second, you need roughly 40 recyclers running full-time on holmium throughput alone. Most functional mid-game setups run 30–60 recyclers.
Can I use quality modules in my scrap recyclers to farm better items?
Yes, with important limits. Recyclers accept quality modules but not productivity modules. The quality upgrade probability caps at approximately 10% per craft regardless of how many modules you install — diminishing returns are severe above two modules per recycler. The best targets are processing units (2% base drop) and advanced circuits (3%) — both are high value and appear regularly enough to justify a dedicated quality recycler bank. Run quality recyclers in parallel with your main array on a tapped belt input, never as a replacement.
What is the fastest path to unlocking the Electromagnetic plant?
The EM plant requires the Electromagnetic Plant research, which consumes a handful of EM science packs — the same packs the plant helps produce more efficiently. The prerequisite chain is: mine ruins → unlock recycling recipe → build holmium chain → produce first EM science packs in standard assemblers at base efficiency → research EM plant. In a functional early Fulgora base, this takes 30–60 minutes from first landing to first EM plant operational.
Are lightning collectors worth building before I have legendary-quality holmium?
Normal-quality lightning collectors are a meaningful upgrade over rods at any quality tier. Double the efficiency (40% vs 20%), double the energy storage (1 GJ vs 500 MJ), and roughly triple the coverage area. Each collector costs 8 supercapacitors to craft, making it a mid-game investment. Build normal-quality collectors as soon as supercapacitors are in steady supply. Legendary collectors — at 100% efficiency and four times the effective output of a legendary rod — are worth targeting eventually, but a functional mid-game base does not require them.
Sources
- Scrap — Factorio Wiki
- Tutorial: Scrap Recycling Strategies — Factorio Wiki
- Fulgora — Factorio Wiki
- Electromagnetic Plant — Factorio Wiki
- Lightning Collector — Factorio Wiki
- Lightning Collector vs. Lightning Rod — Factorio Forums
- Holmium Solution — Factorio Wiki
- Supercapacitor — Factorio Wiki
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