Official Factorio Wiki - User contributions [en]

Power production

2026-11-03T00:50:03Z

Dagorad62: /* Lightning power{{SA}} */ Changed lightning period from inaccurate 10 seconds to 6.48 seconds. Some typos corrected.

{{Languages}}
Electricity has to be produced before it can be transferred to consumers over the [[electric system]]. There are multiple methods to produce electricity:

== Steam engine power ==
Each [[steam engine]] needs 0.5 [[boiler]]s when running at full capacity. One [[offshore pump]] can supply 200 boilers and 400 steam engines.

The above ratio can be calculated from information available in-game: One boiler consumes 1.8MW of fuel and produces energy stored in [[steam]] at 100% efficiency. One steam engine consumes 900kW (0.9MW) of energy stored in steam, so each boiler can supply 2 steam engines: <math>\frac{1.8}{0.9} = 2</math>. One boiler consumes 6 units of [[water]] to produce 60 units of [[steam]] per second, one steam engine consumes 30 steam per second (3 units of water) and one offshore pump produces 1200 water per second, so each offshore pump produces enough water to supply 200 boilers: <math>\frac{1200}{6} = 200</math>. Two steam engines per boiler gives us 400. This produces the 1:200:400 ratio.

[[File:SteamSetupExample.png|center|600px|thumb|A possible setup.]]

== Solar panels and accumulators ==

=== Optimal ratio ===

The optimal ratio is 0.84 (21:25) [[accumulator]]s per [[solar panel]], and 23.8 solar panels per megawatt required by your factory (this ratio accounts for solar panels needed to charge the accumulators). This means that you need 1.428 MW of production (of solar panels) and 100MJ of storage to provide 1 MW of power over one day-night cycle.

A "close enough" ratio is 20:24:1 accumulators to solar panels to megawatts required (for example, a factory requiring 10 MW can be approximately entirely powered, day and night, by 200 accumulators and 240 solar panels - this approximation differs from optimal only in that it calls for 2 extra solar panels, which is negligible but remember that the difference between the "close enough" ratio and the optimal ratio increases as you add more solar panels).

This is taken from [http://www.factorioforums.com/forum/viewtopic.php?f=5&t=5594 Accumulator / Solar Panel Ratio] (which calculates this in an impressive mathematical way!) and [https://forums.factorio.com/viewtopic.php?p=143317#p143317 another post in that thread] (which calculates the solar panel to megawatt ratio in a different way).
[[File:9x9_accumulator_solar_panel_example.jpg|300px|thumb|top|A small 9x9 setup demonstrating the 20:24 "close enough" ratio above.]]

=== Calculations ===

The optimal ratio of accumulators per solar panel relies on many values in the game. These include the power generation of a solar panel, the energy storage of an accumulator, the length of a [[Time#Days|day]], and the length of a night. There are also times between day and night called dusk and dawn which complicate the calculations. In vanilla factorio, without mods which change any of these values, the optimal ratio will be the same. This ratio is

<math> \frac{\mathrm{Accumulators}}{\mathrm{SolarPanels}} = \frac{\left( \mathrm{day} + \mathrm{dawn} \right)}{\mathrm{gameday}} \cdot \left( \mathrm{night} + \frac{\mathrm{dawn} \cdot \left( \mathrm{day} + \mathrm{dawn} \right)}{\mathrm{gameday}} \right) \cdot \frac{\mathrm{SolarPower}}{\mathrm{AccumulatorEnergy}} </math>

which, given the default time lengths of: day = 12500/60 s; dawn or dusk = 5000/60 s; night = 2500/60 s, and the default: Solar_power = 60 kW; Accumulator_energy = 5 MJ = 5000 kJ, gives the optimal ratio of 0.84 accumulators per solar panel. If the player uses mods which change the power generation of solar panels, or the energy storage of accumulators, but not the length of days, a simplified version of this equation can be used.
<pre>Accumulators / Solar_panels = 70 s × Solar_power / Accumulator_energy</pre>

This equation could also be used to remember the vanilla optimal ratio given its simplicity. If the only effect the mod has on the game is it changes the total length of one day, without changing the ratio of dusk : day : dawn : night, then the equation can be simplified as
<pre>Accumulators / Solar_panels = 0.002016 /s × game_day </pre>

where game_day is the number of seconds in the game day which is 25000/60 s by default.

=== Vulcanus ===

In Space Age, the day/night cycle on Vulcanus is 90 seconds with each phase of that cycle proportionally smaller: day = 45 s; dawn or dusk = 18 s; night = 9 s. The formula above simplifies to:

<pre>Accumulators / Solar_panels = 15.2 s × Solar_power / Accumulator_energy</pre>

Additionally, solar power production in Vulcanus atmosphere is 400% of that of Nauvis. With normal quality solar panels and accumulators, the ratio is 0.72576 accumulator per solar panel. 3 accumulators per 4 panel is pretty close.

=== See also ===

* [http://www.factorioforums.com/forum/viewtopic.php?f=5&t=5168 Perfectly optimal solar network (Factorio forums)]
* [http://www.factorioforums.com/forum/viewtopic.php?f=18&t=5394 Solar ratios (Factorio forums)]
* [http://www.factorioforums.com/forum/viewtopic.php?f=5&t=7619 1 solar panel produces 42KW after factoring in the night (Factorio forums)]
* [https://forums.factorio.com/viewtopic.php?p=629003#p629003 Day-Night cycle times in Space Age and Solar Power (Factorio forums)]
* [https://forums.factorio.com/viewtopic.php?f=18&t=119040 Solar Power in Space Age - Definitive Ratios for Planets, Qualities and Throughput-Limits (Factorio forums)]
* [[Tutorial:Solar power math]]

== Nuclear power ==
[[File:Nuclear setup.png|thumb|700px|right|Uranium processing for nuclear power.]]
:''See also: [[Tutorial:Nuclear power]]''
In general, nuclear power is produced by the following production chain: [[Uranium ore]] is mined and [[Uranium processing|processed]] to [[uranium-235]] and [[uranium-238]], then [[uranium fuel cell]]s are created from the two. These fuel cells are then burned in a [[nuclear reactor]] to create heat. The heat is transferred via [[heat pipe]]s to one or more [[heat exchanger]]s, which convert [[water]] to [[steam]] that is then consumed by [[steam turbine]]s to produce power.

A reactor without neighbor bonus needs 4 heat exchangers so that all its heat gets consumed. For each 100% neighbor bonus, the reactor needs 4 more heat exchangers.

{| class="wikitable"
! Ideal Ratio !! Simple Ratio !! Building
|-
| 2 || 1 ||{{imagelink|Offshore pump}}
|-
| 233 || 116 || {{imagelink|Heat exchanger}}
|-
| 400 || 200 || {{imagelink|Steam turbine}}
|}

== Heating tower {{SA}} ==

The [[Heating tower]], initially researched on [[Gleba]], is an alternate source of heat for [[Heat pipe]]s and [[Heat exchanger]]s. Unlike nuclear reactors, heating towers are traditional [[burner devices]], burning standard [[fuel]]s.

Heating towers burn fuel, extracting 16MW of power from the fuel. However, because they have 250% efficiency, they generate 40MW of heat from the fuel. Like a nuclear reactor, the heat must be transferred to heat exchangers to generate useful electricity. Since they use the same fuel, but can produce 2.5x the energy from it, one can think of a heating tower as a [[boiler]] "Mk 2".

A single heating tower can produce the same power output as a single nuclear reactor. However, they do not get neighbor bonuses the way reactors do. As such, the ratio of heating towers to exchangers is always 1:4.

Like reactors, they have a maximum temperature of 1000 C. And also like reactors, they will continue to burn fuel even after they reach their maximum temperature. This gives them a secondary use as a quick way to dispose of unwanted burnable materials, such as excess fruit products/[[spoilage]] on Gleba or excess solid fuel on [[Fulgora]].

Note that heating towers produce less pollution per MW of power produced than boilers. Boilers produce 3.6MW of power per pollution generated, while heating towers produce 24 MW per pollution.

== Lightning power{{SA}} ==
On [[Fulgora]], lightning occurs every night. It ramps up after dusk and ramps down before dawn analogous to how solar works during the day. Each lightning bolt contains 1 GJ of energy and they strike approximately once every 6.48 seconds per chunk (32x32 tiles) averaged over the night. When a [[lightning rod]] or [[lightning collector]] is struck by lightning, it becomes a short-lived source of electrical power. Below is a short overview of how lightning energy is made available to the grid. For brevity this section uses "lightning attractor" or "attractor" when the distinction between rods and collectors is not important.

Lightning attractors have an energy capacity as well as an efficiency value (the latter varies by [[quality]]). The efficiency value determines what fraction of the 1 GJ in the bolt is available to the attractor to recharge it. A normal quality [[lightning rod|rod]] has 20% efficiency, so a single bolt will recharge the rod by up to 20% of 1,000 MJ, or 200 MJ. A normal quality [[lightning collector|collector]], with an efficiency of 40%, will recharge the collector by up to 400 MJ. If the attractor cannot accept the full recharge amount due to reaching it's capacity, any excess is lost.

The charge within an attractor can be released to the grid at an unlimited rate. So even a single rod or collector which has stored energy can meet any power demands of the attached [[Electric system]]. This will provide power to any buildings in the same electrical system as the attractor, including [[accumulator]]s. For a grid with P power demand and N attractors simultaneously charged, each one will provide P/N power to the grid. Of course, higher power draw means the attractor will deplete stored charge faster.

Attractors also have a "drain" discharge rate of 150 MW. While charged, 150 MJ per second (2.5 MJ/tick) of the attractor's charge will be lost, unable to be used for anything. This makes lightning power a "use it or lose it" arrangement. This drain can be viewed as reducing the efficiency of the attractor, depending on grid power demand. See [[Lightning rod #Net Efficiency]] for a more detailed discussion on that. A normal quality lightning rod struck by a single bolt will only generate power for a maximum of 1.33 seconds. A normal quality lightning collector will generate power for a maximum of 2.67 seconds. This means, unless one has a very large grid of connected lightning attractors, at least a few accumulators will be needed even at night to cover gaps in lightning strikes.

The principal advantages of lightning collectors over lightning rods are the larger range for lightning strikes, their higher max capacity, and their higher efficiency. This leads to more consistent power at night and higher sustainable power capabilities. Quality on lightning rod and collectors provides similar benefits to range, capacity, and efficiency.

Since lightning only occurs at night, one must use accumulators to make that energy available during the day. If not using any other source of power during the day, one should place enough accumulators to cover ~60% of the day's duration to be safe. For every 1 MW of base demand, this is 108 MJ of storage (22 - 4 accumulators per MW depending on quality). Note that accumulators add extra load to the grid at night (0.3 - 0.75 MW per accumulator depending on quality). This is actually beneficial as it reduces the lightning energy lost to the drain mechanic.

Broadly speaking, the limiting factor of relying solely on lightning power is the large area requirements of low quality accumulators. Net efficiency and lightning rod quality only become relevant when factory power density increases substantially due to modules and beacons. Lightning power at night can be complemented by using burner power during the day.

== Fusion power{{SA}} ==
Fusion power requires the production of two ingredients to function: [[fusion power cell]]s and [[fluoroketone (cold)]]. Both can only be produced on [[Aquilo]] using the planet's exclusive fluid resources, and [[holmium plate]]s imported from [[Fulgora]].

[[Fusion reactor]]s consume the power cells, cold fluoroketone, and electricity to produce [[plasma]]. The plasma is fed into [[fusion generator]]s which produce electricity and [[fluoroketone (hot)]]. The hot fluoroketone must then be fed into a [[cryogenic plant]] to cool it back down, which can produce a self-sustaining loop. However, as the reactors require electricity (10 mW) to generate plasma, there must be some other power source already on the network to jump-start the system. After that, even a single fusion generator will create enough power to sustain the reactor.

Because [[ammonia|ammonia]], which is needed to produce the power cells cannot be [[barrel|barrelled]], production of them is confined to Aquilo. However, as the cold and hot fluoroketone ''can'' be barreled, it and the power cells can be shipped to other planets with relative ease.

=== Ratio calculations ===

Fusion reactors produce plasma at a base temperature of <math>1.0\,M^\circ \text{C}</math>. Each directly connected reactor adds an additional <math>1.0\,M^\circ \text{C}</math> to the maximum achievable plasma temperature. The actual plasma temperature depends on the neighbor bonuses, which are determined by the arrangement of reactors and their current plasma production rate. For example, if a reactor produces plasma at its maximum rate, all reactors connected to this reactor receive a 100% neighbor bonus. The temperature used by generators is the average plasma temperature of all reactors in the setup.

The optimal ratio of fusion reactors to generators can be calculated in a single step:

<math>G = (R + N) \cdot \frac{P_{O}}{P_{C}}</math>

where:

* <math>G</math> is the optimal number of fusion generators for the given reactor setup
* <math>R</math> is the number of fusion reactors
* <math>N</math> is the sum of the neighbor bonuses of all reactors (expressed as an integer)
* <math>P_O</math> is the maximum plasma output of a reactor
* <math>P_C</math> is the maximum plasma consumption of a generator

Thus, the optimal reactor-to-generator ratio is <math>R:G</math>

If the fusion reactors and generators have the same quality tier (e.g. normal), then the formula simplifies to:

<math>G = 2 \cdot (R + N)</math>

'''Note''':

* This formula applies to all quality tiers and mixed setups where reactors and generators share the same quality tier respectively.
* Initially, a not fully utilized fusion power setup will produce plasma at a lower temperature than what is possible. As more power is needed, more plasma is produced, and therefore the neighbor bonuses rise. With rising neighbor bonuses, the resulting plasma temperature also increases, resulting in more efficient plasma usage. This cycle continues until the setup reaches its maximum plasma temperature, allowing it to deliver peak power output.

== Ensuring enough energy is produced ==

Try this checklist before you completely revamp your power source. You may also use this to rectify [[Glossary#B|brownouts/blackouts]].

* Did you connect the steam engine to the [[electric system]]? If not, a small yellow triangle will flash. To fix, Add some [[Small electric pole|power poles]] near the steam engines that go to machines needing that power. Any power pole will work.
* Is steam able to reach all steam engines?
* Do your pipes have water? Look at the windows in the pipes, hover over the pipes! Place some pipes or a tank at the end to see if there is really water coming through. If not, ensure all [[pipe]]s or [[Pipe to ground|underground pipes]] are connected together.
* Is the factory producing enough fuel (coal, solid fuel, uranium fuel cells)?
* Are there enough steam generators (boilers, heat exchangers)?
* Are there enough steam engines/turbines?

See also the [[Tutorial:Applied_power_math|applied power math tutorial]] to answer the question ''how much coal do I need?''

{{C|Production{{!}}#Power production}} {{C|Energy{{!}}#Power production}}

Rail

2026-10-25T17:45:54Z

Dagorad62: Spacing issue corrected.

{{Languages}}
{{:Infobox:Rail}}

A '''Rail''' is used for building a [[railway]] track for [[locomotive|trains]]. Unlike [[transport belt]]s, rail tracks can also be curved and placed diagonally. [[Train stop]]s, [[rail signal]]s and [[rail chain signal]]s can be placed on rails to better guide automated trains. [[Gate]]s can also be placed on rails, making them rail gates. In [[Space Age]]{{SA}}, rails can be connected to [[rail ramp]]s{{SA}} and [[rail support]]s{{SA}} to build elevated rails. Elevated rails allow trains to freely pass over obstacles.

The minimum rail turning radius is 13, meaning the smallest possible 180° turn has 26 [[Map_structure#Tile|tile]]s between the centers of opposite rails. However, due to rails being two tiles wide, the actual footprint is 28 tiles wide.

The [[rail planner]] can be used to automatically place rails. See the page for more info.

== Achievements ==
Rails are directly related to the following achievements:
{{Achievement|trans-factorio-express}}

== Trivia ==

* The game's "22.5 degree" rails are actually ~26.5 degree, with a 1:2 rise over run which guarantees alignment when shifting. This choice is forced because tan(22.5) = sqrt(2) - 1 is irrational and so true 22.5 degree rails would not be guaranteed to align when shifted arbitrarily in integer increments.

== History ==
{{history|2.1.7|
* {{SA}} Allowed placement of elevated rails over [[cargo bay]]s and blocked them from receiving cargo pods in this state.
* {{SA}} Added "Toggle visibility of tall entities" shortcut which makes elevated rails translucent and unselectable.}}

{{history|2.0.7|
* New rail shapes, rail curves, 22.5 degree tracks. ([https://factorio.com/blog/post/fff-377 Friday Facts #377])
* {{SA}} Added rail ramps, rail supports and elevated rails to build bridges. ([https://factorio.com/blog/post/fff-378 Friday Facts #378])
* Rail planner now attempts to automatically connect to the targeted rail segment.
* Added super forced building mode.
}}

{{history|0.17.29|
* Simplified rail building.
** Holding shift while rail building always activates the combination of ghost-rail-building + remove-obstacles, releasing shift returns back to normal manual mode.
** It doesn't matter anymore, whether the rail building started with shift or not.
** This removed the possibility to do ghost-rail-building without the remove-obstacles, but since it seems to be almost useless, we consider it to be worth the simplification.
}}

{{history|0.13.0|
* [[Rail planner]] tool simplifies rail building.
* Improved the rail selection logic.
* Halved the mining time of rails.
* Removed the curved rail, ''rail'' is the only type now.
}}

{{history|0.12.11|
* Replaced entity type ''rail'' with types ''straight rail'' and ''curved rail''}}

{{history|0.11.17|
* Increased the stack size of Straight Rails to 100 from 50.}}

{{history|0.11.0|
* Gates built on rails now make them rail gates.
* Added end of track graphics.
}}

{{history|0.9.0|
* Rails are now crafted in pairs.
* Nicer rail diagonals/turns on minimap.}}

{{history|0.7.1|
* Added remnants for destroyed rails.}}

{{history|0.5.0|
* Rails are not minable when a train is on them.
* Rails recipe changed, now needs steel and stone
* Rails made more expensive
}}

{{history|0.2.8|
* Correction of bounding boxes of some built curved rails.}}

{{history|0.2.1|
* Rail building and selection boxes}}

{{history|0.1.0|
* Introduced}}

== See also ==
* [[Locomotive]]
* [[Rail planner]]
* [[Railway]]

{{LogisticsNav}}
{{C|Railway}}

2026-10-09T05:08:51Z

Dagorad62: /* Coverage and Tiling */

Lightning rod

2026-10-09T04:56:43Z

Dagorad62: Moved intro text to more appropriate body section. Added table for triangle/square tiling

Lightning rod

2026-10-09T03:48:36Z

Dagorad62: /* Implications */ Further refinements.