Official Factorio Wiki - User contributions [en]

Tutorial:Applied power math

2017-06-17T19:56:39Z

Xavier: Fixed links and minor edits from reddit post

In this tutorial we'll be answering the question: '''how much coal is needed to power a factory?'''

First off, we need to know: how much power does our factory use? That's easy - you can check the electricity tab by clicking on a power pole.

[[File:power-details.png|800px]]

Here we see one radar using 300kW (the 299kW is a rounding error). Factorio uses real science here. A Watt (W) is a measure of energy transfer. A kilowatt (kW) is 1000 W, a megawatt (MW) is 1000 kW, and if you're lucky enough to ever make a factory big enough, a gigawatt (GW) is 1000 MW.

So that answers the question of how much power our factory uses. To keep our factory running at full speed we need to maintain 300 kW. For ease of comparison, we'll convert that to 0.3 MW.

Next question! How much power is stored in coal? That's also easy, because it tells us when we hover over it: 8 MJ.

[[File:coal-joules.png|300px]]

A Joule is another standard measure of stored energy. As with Watts a kilojoule (kJ) is 1000 J, and so on. There is a fixed relationship between Joules and Watts. '''1 Joule can provide 1 Watt of power for 1 second.''' As a formula:

J = W × s

So to run our factory at 0.3 MW, we need to consume 0.3 MJ every second.

== Quiz ==

Assuming perfect efficiency, how long could one piece of coal (8 MJ) run
our single radar (0.3 MW)?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = 0.3 MW * s
s = 8 MJ / 0.3 MW
s = 26.67

Nearly 27 seconds.
</div>
</div>

Assuming perfect efficiency, what is the maximum size factory (in watts)
a single piece of coal could run for 5 seconds?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = MW * 5
MW = 8 MJ / 5
MW = 1.6

1.6 megawatts.
</div>
</div>

'''BONUS!''' A ton of real world coal [http://hypertextbook.com/facts/2006/LunChen.shtml contains about 21 GJ]. How much does a
piece of Factorio coal weigh?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
The energy ratios will match the weight ratios, so:

8 MJ / 21000 MJ = weight / 1000 kG
weight = (8 MJ / 21000 MJ) * 1000 kG
weight = 0.38 kG

About 400g! Still doesn't explain how our character can carry so much of it...
</div>
</div>

== Efficiency ==

Let's test it! We should be able to run a radar for 27 seconds, right? Using a setup with a single boiler, steam engine, and radar, we can drop a single piece of coal in the boiler and see how long the radar runs.

[[File:radar-example.png|800px]]

We barely got 20s! What's wrong? We are generating less power than expected.
Let's measure using an accumulator.

[[File:Accumulator-example.png|800px]]

We started with 8 MJ in the coal, but only 4 MJ ended up in the accumulator.
This is because, like in the real world, some energy is lost along the way as
waste. In this case, only 50% is making it into our accumulator. In Factorio,
this loss happens in the boiler, and it actually tells us this in the item details! You can think of the waste 50% as going into the pollution it generates...

[[File:boiler-details.png]]

Now we have everything we need to answer our initial question: '''how much coal do we need to power our factory?''' Well, the question actually needs to be a bit
more precise: how much coal do we need ''per second'' to power our factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Aside: why did the radar run for 20s and not 13.5s (50% of 27s)?'''
<div class="mw-collapsible-content">
Because it doesn't turn on and off instantly. As you can see in the graph, it ramps up then ramps down. Technically, if you measured the area under the curve it would give you the expected 4 MJ.
</div>
</div>

== Quiz ==

How much coal per second is needed to power a 20 MW factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Since <code>J = W × s</code>, a 20 MW factory will consume 20 MJ/s. We'll need 40 MJ/s input due to the 50% boiler efficiency loss. Since coal contains 8 MJ, we'll need '''5 coal per second''' (<code>5 × 8 MJ = 40 MJ</code>).
</div>
</div>

'''BONUS!''' How many [[Mining|mining drills]] are needed to produce that much coal?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Per the linked page, an electric mining drill produces ~0.5/s, so we'll need '''10 electric mining drills''' (<code>10 × 0.5 = 5</code>).
</div>
</div>

'''SECOND BONUS!''' The average American household uses [https://www.eia.gov/tools/faqs/faq.php?id=97&t=3 3.2 GJ in a month] (typically expressed as ''888 kilowatt hours''). How much Factorio coal would be needed to power one of these homes for that period, and how many homes could a steam engine support ([[Steam_engine|510 kW]]), assuming the power is used at a constant rate? (Assume 30 days in a month.)

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">

3.2 GJ = 3,200 MJ
3200 MJ / (8 MJ * 50%) = 800

3200 MJ / 30 days / 24 hours / 60 minutes / 60 seconds = 1,235 W
510,000 / 1235 = 412

800 pieces of coal per household, and a single steam engine could power 412 households.
</div>
</div>

[[Category:Tutorial]]

Tutorial:Applied power math

2017-03-25T19:07:39Z

Xavier: Added an extra bonus question that I thought was fun

In this tutorial we'll be answering the question: '''how much coal is needed to power a factory?'''

First off, we need to know: how much power does our factory use? That's easy - you can check the electricity tab by clicking on a power pole.

[[File:power-details.png|800px]]

Here we see one radar using 300kW (the 299kW is a rounding error). Factorio uses real science here. A Watt (W) is a measure of energy transfer. A kilowatt (kW) is 1000 W, a megawatt (MW) is 1000 kW, and if you're lucky enough to ever make a factory big enough, a gigawatt (GW) is 1000 MW.

So that answers the question of how much power our factory uses. To keep our factory running at full speed we need to maintain 300 kW. For ease of comparison, we'll convert that to 0.3 MW.

Next question! How much power is stored in coal? That's also easy, because it tells us when we hover over it: 8 MJ.

[[File:coal-joules.png|300px]]

A Joule is another standard measure of stored energy. As with Watts a kilojoule (kJ) is 1000 J, and so on. There is a fixed relationship between Joules and Watts. '''1 Joule can provide 1 Watt of energy for 1 second.''' As a formula:

J = W × s

So to run our factory at 0.3 MW, we need to consume 0.3 MJ every second.

== Quiz ==

Assuming perfect efficiency, how long could one piece of coal (8 MJ) run
our single radar (0.3 MW)?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = 0.3 MW * s
s = 8 MJ / 0.3 MW
s = 26.67

Nearly 27 seconds.
</div>
</div>

Assuming perfect efficiency, what is the maximum size factory (in watts)
a single piece of coal could run for 5 seconds?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = MW * 5
MW = 8 MJ / 5
MW = 1.6

1.6 megawatts.
</div>
</div>

'''BONUS!''' A ton of real world coal [http://hypertextbook.com/facts/2006/LunChen.shtml|contains about 21 GJ]. How much does a
piece of Factorio coal weigh?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
The energy ratios will match the weight ratios, so:

8 MJ / 21000 MJ = weight / 1000 kG
weight = (8 MJ / 21000 MJ) * 1000 kG
weight = 0.38 kG

About 400g! Still doesn't explain how our character can carry so much of it...
</div>
</div>

== Efficiency ==

Let's test it! We should be able to run a radar for 27 seconds, right? Using a setup with a single boiler, steam engine, and radar, we can drop a single piece of coal in the boiler and see how long the radar runs.

[[File:radar-example.png|800px]]

We barely got 20s! What's wrong? We are generating less power than expected.
Let's measure using an accumulator.

[[File:Accumulator-example.png|800px]]

We started with 8 MJ in the coal, but only 4 MJ ended up in the accumulator.
This is because, like in the real world, some energy is lost along the way as
waste. In this case, only 50% is making it into our accumulator. In Factorio,
this loss happens in the boiler, and it actually tells us this in the item details! You can think of the waste 50% as going into the pollution it generates...

[[File:boiler-details.png]]

Now we have everything we need to answer our initial question: '''how much coal do we need to power our factory?''' Well, the question actually needs to be a bit
more precise: how much coal do we need ''per second'' to power our factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Aside: why did the radar run for 20s and not 13.5s (50% of 27s)?'''
<div class="mw-collapsible-content">
Because it doesn't turn on and off instantly. As you can see in the graph, it ramps up then ramps down. Technically, if you measured the area under the curve it would give you the expected 4 MJ.
</div>
</div>

== Quiz ==

How much coal per second is needed to power a 20 MW factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Since <code>J = W × s</code>, a 20 MW factory will consume 20 MJ/s. We'll need 40 MJ/s input due to the 50% boiler efficiency loss. Since coal contains 8 MJ, we'll need '''5 coal per second''' (<code>5 × 8 MJ = 40 MJ</code>).
</div>
</div>

'''BONUS!''' How many [[Mining|mining drills]] are needed to produce that much coal?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Per the linked page, an electric mining drill produces ~0.5/s, so we'll need '''10 electric mining drills''' (<code>10 × 0.5 = 5</code>).
</div>
</div>

'''SECOND BONUS!''' The average American household uses [https://www.eia.gov/tools/faqs/faq.php?id=97&t=3|3.2 GJ in a month] (typically expressed as ''888 kilowatt hours''). How much Factorio coal would be needed to power one of these homes for that period, and how many homes could a steam engine support ([[Steam_engine|510 kW]]), assuming the power is used at a constant rate? (Assume 30 days in a month.)

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">

3.2 GJ = 3,200 MJ
3200 MJ / (8 MJ * 50%) = 800

3200 MJ / 30 days / 24 hours / 60 minutes / 60 seconds = 1,235 W
510,000 / 1235 = 412

800 pieces of coal per household, and a single steam engine could power 412 households.
</div>
</div>

Power production

2017-03-25T18:10:49Z

Xavier: /* The electric priority */

{{languages}}
Electricity and [[Liquids]] have many interactions and can be incredibly difficult to learn- this page documents several important components of electricity production. It is divided up into different topics that are important to keep in mind.

== Steam power optimal ratios ==

Each [[Steam engine]] needs roughly 1.31 [[Boiler]]s when running at full capacity.

One [[Pump|offshore pump]] can satisfy 14 [[Boiler]]s and 10 [[Steam engine|steam engines]]. 13 boilers will work, but this tends to have issues recovering after coal shortages or other accidents.

Each 10 steam engines need 2.5 [[electric mining drill]]s when running at full capacity. This is calculated as follows: mining drills produce 0.525 [[coal]]/second. Coal contains 8 MJ of energy, and boilers are 50% efficient, so every mining drill generates 2.1 MJ/second in the boilers. To reach 5.1 MW you need 5.1/2.1 = about 2.5 mining drills.

=== See also ===
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=5950 Research topic about energy]
* [[Liquids/Hot|Hot Liquids]]
* [[Liquids/Pipe physics]].

== Solar Panels/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).

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).

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).

{| style="float:right; padding-left:10px; padding-right:10px;">
| style="padding-right:1em" | [[File:9x9_accumulator_solar_panel_example.jpg|300px|thumb|top|A small 9x9 blueprint demonstrating the 20:24 "close enough" ratio above.]]
| style="padding-right:1em" | [[File:28x28_accumulator_solar_panel_example.jpg|300px|thumb|top|A medium 28x28 blueprint with a nearly optimal ratio.]]
| style="padding-right:1em" | [[File:48x48_accumulator_solar_panel_example.jpg|300px|thumb|top|A large 48x48 blueprint with a nearly optimal ratio. It also contains a roboport in the center to repair itself and automatically construct adjacent blueprint copies.]]
|}
=== 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 [[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
<pre>Accumulators / Solar_panels =
(day + dawn) * (night + dawn * (day + dawn) / game_day) / game_day
* Solar_power / Accumulator_energy</pre>

which, given the default time lengths of: day = 17500/60 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 <b>not</b> 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.

=== See also ===

* http://www.factorioforums.com/forum/viewtopic.php?f=5&t=5168
* http://www.factorioforums.com/forum/viewtopic.php?f=18&t=5394
* http://www.factorioforums.com/forum/viewtopic.php?f=5&t=7619
* http://www.factorioforums.com/forum/viewtopic.php?f=8&t=1865

== Ensuring enough energy is produced ==

Try this checklist before you completely revamp your power source. You may also use this to rectify negative feedback loops.

* Did you connect the steam engine to the [[Electric network]]? 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 size will work.
* Is hot water able to reach all steam engines?
* Do your pipes have water? Look at the glass 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 [https://wiki.factorio.com/index.php?title=Pipe-to-Ground underground pipes] are connected together.
* Do you have enough [[Boiler]]s? The water temperature should reach 100 degrees. One of your burners should be reserve (not much used, no lights in the burner) when you need to restart the energy system.

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

== Energy Storage ==

See [[Basic accumulator]].

Energy is available (or storable) from/to:
* [[Fuel]].
* Capacity in the [[Basic accumulator]]s.
* [[Liquids/Hot|Hot liquids]]. They can be created in the [[Boiler]] and stored in the [[Storage Tank]]. See below.

See [[Units#Power]] for info on energy units.

=== Storing hot water in tanks ===

A completely filled tank with water at 100 degrees stores 212 Megajoules! This is the equivalent to 42 [[Basic accumulator]]s, but the tank needs only 3x3 tiles of space. This way you can store much more energy in a much smaller place: 23.5 MJ / [[Tile]] vs. 1.2 MJ / [[Tile]]

The details are explained in [[Liquids/Pipe physics]]. Read more about this: [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=6617&start=10#p52712 Yet another "Steam engine backup" solution (simple&low tech)].

There are several advantages to storing energy in storage tanks vs. storing it in an [[Electricity/Storage|accumulator]]:
* You don't need to produce electrical energy first.
* The energy density per tile is much higher than it is with batteries.
* You won't get sudden blackouts when you're out of power. Instead, power goes out gradually as pressure drops.

==== See also ====
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=9738 Hot water capacitor]
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=6665 Using steam as a backup]
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=3724 Handling Gigantic Energy Peaks]
* [[Liquids/Hot]].

== Types of energy ==

In factorio, there are two types of energy, Burner, and Electric.

=== Burner ===

Burner energy is energy obtained from burning [[Fuel]] in a machine, such as a [[Burner Mining Drill]], or [[Car]].

=== Electric ===

Electricity is produced by generators, or energy storages when draining. It is an intangible energy that flows through power poles.

Electricity is the only way to transport energy over long distances quickly. Electricity itself doesn't pollute, pollution comes either from burning fuel or consuming electricity. Different amounts of energy consumption yield differing amounts of pollution.

Common sources of electric power are [[steam engine]]s, [[Basic accumulator]]s, or [[solar panel]]s.

=== The electric priority ===

Electricity is provided on a priority basis. When a draw for power is created, power will come from these machines, in order. This means:

* [[Solar panel]] - These will provide power first, if they do not satisfy the draw...
* [[Steam engine]] - Steam engines will start functioning, if the draw is still not satisfied...
* [[Basic accumulator]] - Lastly, the energy in accumulators will be consumed.

This works in the opposite way as well: The accumulators are only filled if the demand of all other consumers are fulfilled.

== Transmitting energy ==

=== Poles ===

Power poles are used to transmit energy. See [[Small electric pole]], [[Medium electric pole]], and [[Big electric pole]] for more info.

==== Autoplacing poles ====

It is possible to automatically place poles at maximum distance apart. To do this, left click and hold, then move the mouse or walk. The poles will automatically be placed the optimal distance apart.

This works from a car or train as well, which enables placing the electric poles very quickly over long distances.

=== Cables (and Wires) ===

When you place an electric pole it will automatically cable itself to other poles in range. These cables are "free" and do not consume any copper cable. If you remove these cables, you can regenerate them by removing and rebuilding the pole.

You generally don't need to manually add copper wires, because any pole in range will be connected automatically by the free wires. Placing copper wire is only useful when precise control is needed, such as hooking up a [[power switch]] between two networks.

==== Removing cables ====
Remove all cables from an electric pole by shift-left-clicking it. The pole will become an independent electric network. You can reconnect it to other poles by placing cables manually.

==== Add cables or wires ====
A cable or wire can be added by holding [[Copper cable]] in your hand, left-clicking the base of one pole, then left-clicking the base of another. Use [[copper cable]] for the electric network, or [[red wire|red]]/[[green wire|green]] wires for the [[circuit network]]s. Note that the wire item is consumed when you make the connection; you will not get it back if you remove the pole's wires, or if you remove the pole itself.

Power production

2017-03-25T18:09:49Z

Xavier: Removed top level "hot water in tanks" section. It's a weird thing to be right up near the top, and it's already covered in a subsection.

{{languages}}
Electricity and [[Liquids]] have many interactions and can be incredibly difficult to learn- this page documents several important components of electricity production. It is divided up into different topics that are important to keep in mind.

== Steam power optimal ratios ==

Each [[Steam engine]] needs roughly 1.31 [[Boiler]]s when running at full capacity.

One [[Pump|offshore pump]] can satisfy 14 [[Boiler]]s and 10 [[Steam engine|steam engines]]. 13 boilers will work, but this tends to have issues recovering after coal shortages or other accidents.

Each 10 steam engines need 2.5 [[electric mining drill]]s when running at full capacity. This is calculated as follows: mining drills produce 0.525 [[coal]]/second. Coal contains 8 MJ of energy, and boilers are 50% efficient, so every mining drill generates 2.1 MJ/second in the boilers. To reach 5.1 MW you need 5.1/2.1 = about 2.5 mining drills.

=== See also ===
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=5950 Research topic about energy]
* [[Liquids/Hot|Hot Liquids]]
* [[Liquids/Pipe physics]].

== Solar Panels/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).

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).

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).

{| style="float:right; padding-left:10px; padding-right:10px;">
| style="padding-right:1em" | [[File:9x9_accumulator_solar_panel_example.jpg|300px|thumb|top|A small 9x9 blueprint demonstrating the 20:24 "close enough" ratio above.]]
| style="padding-right:1em" | [[File:28x28_accumulator_solar_panel_example.jpg|300px|thumb|top|A medium 28x28 blueprint with a nearly optimal ratio.]]
| style="padding-right:1em" | [[File:48x48_accumulator_solar_panel_example.jpg|300px|thumb|top|A large 48x48 blueprint with a nearly optimal ratio. It also contains a roboport in the center to repair itself and automatically construct adjacent blueprint copies.]]
|}
=== 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 [[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
<pre>Accumulators / Solar_panels =
(day + dawn) * (night + dawn * (day + dawn) / game_day) / game_day
* Solar_power / Accumulator_energy</pre>

which, given the default time lengths of: day = 17500/60 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 <b>not</b> 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.

=== See also ===

* http://www.factorioforums.com/forum/viewtopic.php?f=5&t=5168
* http://www.factorioforums.com/forum/viewtopic.php?f=18&t=5394
* http://www.factorioforums.com/forum/viewtopic.php?f=5&t=7619
* http://www.factorioforums.com/forum/viewtopic.php?f=8&t=1865

== Ensuring enough energy is produced ==

Try this checklist before you completely revamp your power source. You may also use this to rectify negative feedback loops.

* Did you connect the steam engine to the [[Electric network]]? 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 size will work.
* Is hot water able to reach all steam engines?
* Do your pipes have water? Look at the glass 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 [https://wiki.factorio.com/index.php?title=Pipe-to-Ground underground pipes] are connected together.
* Do you have enough [[Boiler]]s? The water temperature should reach 100 degrees. One of your burners should be reserve (not much used, no lights in the burner) when you need to restart the energy system.

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

== Energy Storage ==

See [[Basic accumulator]].

Energy is available (or storable) from/to:
* [[Fuel]].
* Capacity in the [[Basic accumulator]]s.
* [[Liquids/Hot|Hot liquids]]. They can be created in the [[Boiler]] and stored in the [[Storage Tank]]. See below.

See [[Units#Power]] for info on energy units.

=== Storing hot water in tanks ===

A completely filled tank with water at 100 degrees stores 212 Megajoules! This is the equivalent to 42 [[Basic accumulator]]s, but the tank needs only 3x3 tiles of space. This way you can store much more energy in a much smaller place: 23.5 MJ / [[Tile]] vs. 1.2 MJ / [[Tile]]

The details are explained in [[Liquids/Pipe physics]]. Read more about this: [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=6617&start=10#p52712 Yet another "Steam engine backup" solution (simple&low tech)].

There are several advantages to storing energy in storage tanks vs. storing it in an [[Electricity/Storage|accumulator]]:
* You don't need to produce electrical energy first.
* The energy density per tile is much higher than it is with batteries.
* You won't get sudden blackouts when you're out of power. Instead, power goes out gradually as pressure drops.

==== See also ====
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=9738 Hot water capacitor]
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=6665 Using steam as a backup]
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=3724 Handling Gigantic Energy Peaks]
* [[Liquids/Hot]].

== Types of energy ==

In factorio, there are two types of energy, Burner, and Electric.

=== Burner ===

Burner energy is energy obtained from burning [[Fuel]] in a machine, such as a [[Burner Mining Drill]], or [[Car]].

=== Electric ===

Electricity is produced by generators, or energy storages when draining. It is an intangible energy that flows through power poles.

Electricity is the only way to transport energy over long distances quickly. Electricity itself doesn't pollute, pollution comes either from burning fuel or consuming electricity. Different amounts of energy consumption yield differing amounts of pollution.

Common sources of electric power are [[steam engine]]s, [[Basic accumulator]]s, or [[solar panel]]s.

=== The electric priority ===

Electricity is provided on a priority basis. When a draw for power is created, power will come from these machines, in order:
This means,

* [[Solar panel]]- These will provide power first, if they do not satisfy the draw:
* [[Steam engine]]- Steam engines will start functioning, if the draw is still not satisfied:
* [[Basic accumulator]]- Lastly, the energy in accumulators will be consumed.

This works in the opposite way as well: The accumulators are only filled if the demand of all other consumers are fulfilled.

== Transmitting energy ==

=== Poles ===

Power poles are used to transmit energy. See [[Small electric pole]], [[Medium electric pole]], and [[Big electric pole]] for more info.

==== Autoplacing poles ====

It is possible to automatically place poles at maximum distance apart. To do this, left click and hold, then move the mouse or walk. The poles will automatically be placed the optimal distance apart.

This works from a car or train as well, which enables placing the electric poles very quickly over long distances.

=== Cables (and Wires) ===

When you place an electric pole it will automatically cable itself to other poles in range. These cables are "free" and do not consume any copper cable. If you remove these cables, you can regenerate them by removing and rebuilding the pole.

You generally don't need to manually add copper wires, because any pole in range will be connected automatically by the free wires. Placing copper wire is only useful when precise control is needed, such as hooking up a [[power switch]] between two networks.

==== Removing cables ====
Remove all cables from an electric pole by shift-left-clicking it. The pole will become an independent electric network. You can reconnect it to other poles by placing cables manually.

==== Add cables or wires ====
A cable or wire can be added by holding [[Copper cable]] in your hand, left-clicking the base of one pole, then left-clicking the base of another. Use [[copper cable]] for the electric network, or [[red wire|red]]/[[green wire|green]] wires for the [[circuit network]]s. Note that the wire item is consumed when you make the connection; you will not get it back if you remove the pole's wires, or if you remove the pole itself.

Power production

2017-03-25T18:08:15Z

Xavier: /* Ensuring enough energy is produced */ Added relevant tutorial link.

{{languages}}
Electricity and [[Liquids]] have many interactions and can be incredibly difficult to learn- this page documents several important components of electricity production. It is divided up into different topics that are important to keep in mind.

== Steam power optimal ratios ==

Each [[Steam engine]] needs roughly 1.31 [[Boiler]]s when running at full capacity.

One [[Pump|offshore pump]] can satisfy 14 [[Boiler]]s and 10 [[Steam engine|steam engines]]. 13 boilers will work, but this tends to have issues recovering after coal shortages or other accidents.

Each 10 steam engines need 2.5 [[electric mining drill]]s when running at full capacity. This is calculated as follows: mining drills produce 0.525 [[coal]]/second. Coal contains 8 MJ of energy, and boilers are 50% efficient, so every mining drill generates 2.1 MJ/second in the boilers. To reach 5.1 MW you need 5.1/2.1 = about 2.5 mining drills.

=== See also ===
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=5950 Research topic about energy]
* [[Liquids/Hot|Hot Liquids]]
* [[Liquids/Pipe physics]].

== Hot liquids in tanks ==

To equalize the needed throughput (different needs of energy between day and night for example), hot water from boilers can also be stored in [[Storage Tank|storage tanks]] and used by extra steam engines during peak times or during night (if solar is in place). This energy storage technique can be used instead of or in addition to [[Basic accumulator|accumulators]]. Hot liquids stored in tanks will never cool down.

See [[Liquids/Hot#Storing_hot_liquids_as_energy_storage|about storing of hot liquids]] for examples on how to use this feature.

== Solar Panels/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).

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).

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).

{| style="float:right; padding-left:10px; padding-right:10px;">
| style="padding-right:1em" | [[File:9x9_accumulator_solar_panel_example.jpg|300px|thumb|top|A small 9x9 blueprint demonstrating the 20:24 "close enough" ratio above.]]
| style="padding-right:1em" | [[File:28x28_accumulator_solar_panel_example.jpg|300px|thumb|top|A medium 28x28 blueprint with a nearly optimal ratio.]]
| style="padding-right:1em" | [[File:48x48_accumulator_solar_panel_example.jpg|300px|thumb|top|A large 48x48 blueprint with a nearly optimal ratio. It also contains a roboport in the center to repair itself and automatically construct adjacent blueprint copies.]]
|}
=== 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 [[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
<pre>Accumulators / Solar_panels =
(day + dawn) * (night + dawn * (day + dawn) / game_day) / game_day
* Solar_power / Accumulator_energy</pre>

which, given the default time lengths of: day = 17500/60 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 <b>not</b> 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.

=== See also ===

* http://www.factorioforums.com/forum/viewtopic.php?f=5&t=5168
* http://www.factorioforums.com/forum/viewtopic.php?f=18&t=5394
* http://www.factorioforums.com/forum/viewtopic.php?f=5&t=7619
* http://www.factorioforums.com/forum/viewtopic.php?f=8&t=1865

== Ensuring enough energy is produced ==

Try this checklist before you completely revamp your power source. You may also use this to rectify negative feedback loops.

* Did you connect the steam engine to the [[Electric network]]? 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 size will work.
* Is hot water able to reach all steam engines?
* Do your pipes have water? Look at the glass 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 [https://wiki.factorio.com/index.php?title=Pipe-to-Ground underground pipes] are connected together.
* Do you have enough [[Boiler]]s? The water temperature should reach 100 degrees. One of your burners should be reserve (not much used, no lights in the burner) when you need to restart the energy system.

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

== Energy Storage ==

See [[Basic accumulator]].

Energy is available (or storable) from/to:
* [[Fuel]].
* Capacity in the [[Basic accumulator]]s.
* [[Liquids/Hot|Hot liquids]]. They can be created in the [[Boiler]] and stored in the [[Storage Tank]]. See below.

See [[Units#Power]] for info on energy units.

=== Storing hot water in tanks ===

A completely filled tank with water at 100 degrees stores 212 Megajoules! This is the equivalent to 42 [[Basic accumulator]]s, but the tank needs only 3x3 tiles of space. This way you can store much more energy in a much smaller place: 23.5 MJ / [[Tile]] vs. 1.2 MJ / [[Tile]]

The details are explained in [[Liquids/Pipe physics]]. Read more about this: [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=6617&start=10#p52712 Yet another "Steam engine backup" solution (simple&low tech)].

There are several advantages to storing energy in storage tanks vs. storing it in an [[Electricity/Storage|accumulator]]:
* You don't need to produce electrical energy first.
* The energy density per tile is much higher than it is with batteries.
* You won't get sudden blackouts when you're out of power. Instead, power goes out gradually as pressure drops.

==== See also ====
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=9738 Hot water capacitor]
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=6665 Using steam as a backup]
* [http://www.factorioforums.com/forum/viewtopic.php?f=8&t=3724 Handling Gigantic Energy Peaks]
* [[Liquids/Hot]].

== Types of energy ==

In factorio, there are two types of energy, Burner, and Electric.

=== Burner ===

Burner energy is energy obtained from burning [[Fuel]] in a machine, such as a [[Burner Mining Drill]], or [[Car]].

=== Electric ===

Electricity is produced by generators, or energy storages when draining. It is an intangible energy that flows through power poles.

Electricity is the only way to transport energy over long distances quickly. Electricity itself doesn't pollute, pollution comes either from burning fuel or consuming electricity. Different amounts of energy consumption yield differing amounts of pollution.

Common sources of electric power are [[steam engine]]s, [[Basic accumulator]]s, or [[solar panel]]s.

=== The electric priority ===

Electricity is provided on a priority basis. When a draw for power is created, power will come from these machines, in order:
This means,

* [[Solar panel]]- These will provide power first, if they do not satisfy the draw:
* [[Steam engine]]- Steam engines will start functioning, if the draw is still not satisfied:
* [[Basic accumulator]]- Lastly, the energy in accumulators will be consumed.

This works in the opposite way as well: The accumulators are only filled if the demand of all other consumers are fulfilled.

== Transmitting energy ==

=== Poles ===

Power poles are used to transmit energy. See [[Small electric pole]], [[Medium electric pole]], and [[Big electric pole]] for more info.

==== Autoplacing poles ====

It is possible to automatically place poles at maximum distance apart. To do this, left click and hold, then move the mouse or walk. The poles will automatically be placed the optimal distance apart.

This works from a car or train as well, which enables placing the electric poles very quickly over long distances.

=== Cables (and Wires) ===

When you place an electric pole it will automatically cable itself to other poles in range. These cables are "free" and do not consume any copper cable. If you remove these cables, you can regenerate them by removing and rebuilding the pole.

You generally don't need to manually add copper wires, because any pole in range will be connected automatically by the free wires. Placing copper wire is only useful when precise control is needed, such as hooking up a [[power switch]] between two networks.

==== Removing cables ====
Remove all cables from an electric pole by shift-left-clicking it. The pole will become an independent electric network. You can reconnect it to other poles by placing cables manually.

==== Add cables or wires ====
A cable or wire can be added by holding [[Copper cable]] in your hand, left-clicking the base of one pole, then left-clicking the base of another. Use [[copper cable]] for the electric network, or [[red wire|red]]/[[green wire|green]] wires for the [[circuit network]]s. Note that the wire item is consumed when you make the connection; you will not get it back if you remove the pole's wires, or if you remove the pole itself.

Tutorial:Applied power math

2017-03-25T18:01:12Z

Xavier:

In this tutorial we'll be answering the question: '''how much coal is needed to power a factory?'''

First off, we need to know: how much power does our factory use? That's easy - you can check the electricity tab by clicking on a power pole.

[[File:power-details.png|800px]]

Here we see one radar using 300kW (the 299kW is a rounding error). Factorio uses real science here. A Watt (W) is a measure of energy transfer. A kilowatt (kW) is 1000 W, a megawatt (MW) is 1000 kW, and if you're lucky enough to ever make a factory big enough, a gigawatt (GW) is 1000 MW.

So that answers the question of how much power our factory uses. To keep our factory running at full speed we need to maintain 300 kW. For ease of comparison, we'll convert that to 0.3 MW.

Next question! How much power is stored in coal? That's also easy, because it tells us when we hover over it: 8 MJ.

[[File:coal-joules.png|300px]]

A Joule is another standard measure of stored energy. As with Watts a kilojoule (kJ) is 1000 J, and so on. There is a fixed relationship between Joules and Watts. '''1 Joule can provide 1 Watt of energy for 1 second.''' As a formula:

J = W × s

So to run our factory at 0.3 MW, we need to consume 0.3 MJ every second.

== Quiz ==

Assuming perfect efficiency, how long could one piece of coal (8 MJ) run
our single radar (0.3 MW)?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = 0.3 MW * s
s = 8 MJ / 0.3 MW
s = 26.67

Nearly 27 seconds.
</div>
</div>

Assuming perfect efficiency, what is the maximum size factory (in watts)
a single piece of coal could run for 5 seconds?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = MW * 5
MW = 8 MJ / 5
MW = 1.6

1.6 megawatts.
</div>
</div>

'''BONUS!''' A ton of real world coal [http://hypertextbook.com/facts/2006/LunChen.shtml|contains about 21 GJ]. How much does a
piece of Factorio coal weigh?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
The energy ratios will match the weight ratios, so:

8 MJ / 21000 MJ = weight / 1000 kG
weight = (8 MJ / 21000 MJ) * 1000 kG
weight = 0.38 kG

About 400g! Still doesn't explain how our character can carry so much of it...
</div>
</div>

== Efficiency ==

Let's test it! We should be able to run a radar for 27 seconds, right? Using a setup with a single boiler, steam engine, and radar, we can drop a single piece of coal in the boiler and see how long the radar runs.

[[File:radar-example.png|800px]]

We barely got 20s! What's wrong? We are generating less power than expected.
Let's measure using an accumulator.

[[File:Accumulator-example.png|800px]]

We started with 8 MJ in the coal, but only 4 MJ ended up in the accumulator.
This is because, like in the real world, some energy is lost along the way as
waste. In this case, only 50% is making it into our accumulator. In Factorio,
this loss happens in the boiler, and it actually tells us this in the item details! You can think of the waste 50% as going into the pollution it generates...

[[File:boiler-details.png]]

Now we have everything we need to answer our initial question: '''how much coal do we need to power our factory?''' Well, the question actually needs to be a bit
more precise: how much coal do we need ''per second'' to power our factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Aside: why did the radar run for 20s and not 13.5s (50% of 27s)?'''
<div class="mw-collapsible-content">
Because it doesn't turn on and off instantly. As you can see in the graph, it ramps up then ramps down. Technically, if you measured the area under the curve it would give you the expected 4 MJ.
</div>
</div>

== Quiz ==

How much coal per second is needed to power a 20 MW factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Since <code>J = W × s</code>, a 20 MW factory will consume 20 MJ/s. We'll need 40 MJ/s input due to the 50% boiler efficiency loss. Since coal contains 8 MJ, we'll need '''5 coal per second''' (<code>5 × 8 MJ = 40 MJ</code>).
</div>
</div>

'''BONUS!''' How many [[Mining|mining drills]] are needed to produce that much coal?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Per the linked page, an electric mining drill produces ~0.5/s, so we'll need '''10 electric mining drills''' (<code>10 × 0.5 = 5</code>).
</div>
</div>

File:Accumulator-example.png

2017-03-25T17:55:50Z

Xavier: Xavier moved page File:Accumulator-example.PNG to File:Accumulator-example.png: lowercase

Tutorial:Applied power math

2017-03-25T17:55:15Z

Xavier:

{{construction}}

In this tutorial we'll be answering the question: '''how much coal is needed to power our factory?'''

First off, we need to know: how much power does our factory use? That's easy &emdash; you can check the electricity tab by clicking on a power pole.

[[File:power-details.png|800px]]

Here we see one radar using 300kW (the 299kW is a rounding error). Factorio uses real science here. A Watt (W) is a measure of energy transfer. A kilowatt (kW) is 1000 W, a megawatt (MW) is 1000 kW, and if you're lucky enough to ever make a factory big enough, a gigawatt (GW) is 1000 MW.

So that answers the question of how much power our factory uses. To keep our factory running at full speed we need to maintain 300 kW. For ease of comparison, we'll convert that to 0.3 MW

Next question! How much power is stored in coal? That's also easy, because it tells us when we hover over it: 8 MJ.

[[File:coal-joules.png|300px]]

A Joule is another standard measure of stored energy. As with Watts a kilojoule (kJ) is 1000 J, and so on. There is a fixed relationship between Joules and Watts. 1 Joule can provide 1 Watt of energy for 1 second. As a formula:

J = W × s

So to run our factory at 0.3 MW, we need to consume 0.3 MJ every second.

== Quiz ==

Assuming perfect efficiency, how long could one piece of coal (8 MJ) run
our factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = 0.3 MW * s
s = 8 MJ / 0.3 MW
s = 26.67

Nearly 27 seconds.
</div>
</div>

Assuming perfect efficiency, what is the maximum size factory (in watts)
a single piece of coal could run for 5 seconds?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = MW * 5
MW = 8 MJ / 5
MW = 1.6

1.6 megawatts.
</div>
</div>

'''BONUS!''' A ton of real world coal [http://hypertextbook.com/facts/2006/LunChen.shtml|contains about 21 GJ]. How much does a
piece of factorio coal weigh?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
The energy ratios will match the weight ratios, so:

8 MJ / 21000 MJ = weight / 1000 kG
weight = (8 MJ / 21000 MJ) * 1000 kG
weight = 0.38 kG

About 400g! Still doesn't explain how our character can carry so much of it...
</div>
</div>

== Efficiency ==

Let's test it! We should be able to run a radar for 27 seconds, right? Using a setup with a single boiler, steam engine, and radar, we can drop a single piece of coal in the boiler and see how long the radar runs.

[[File:radar-example.png|800px]]

We barely got 20s! What's wrong? We are generating less power than expected.
Let's measure using an accumulator.

[[File:Accumulator-example.png]]

We started with 8 MJ in the coal, but only 4 MJ ended up in the accumulator.
This is because, like in the real world, some energy is lost along the way as
waste. In this case, only 50% is making it into our accumulator. In Factorio,
this loss happens in the boiler, and it actually tells us this in the item details! You can think of the waste 50% as going into the pollution it generates...

[[File:boiler-details.png]]

Now we have everything we need to answer our initial question: '''how much coal do we need to power our factory?''' Well, the question actually needs to be a bit
more precise: how much coal do we need ''per second'' to power our factory.

<div class="toccolours mw-collapsible mw-collapsed">
'''Aside: why did the radar run for 20s and not 13.5s (50% of 27s)?'''
<div class="mw-collapsible-content">
Because it doesn't turn on and off instantly. As you can see in the graph, it ramps up then ramps down. Technically, if you measured the area under the curve it would give you the expected 4 MJ.
</div>
</div>

== Quiz ==

How much coal per second is needed to power a 20 MW factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Since <code>J = W × s</code>, a 20 MW factory will consume 20 MJ/s. We'll need 40 MJ/s input due to the 50% boiler efficiency loss. Since coal contains 8 MJ, we'll need '''5 coal per second''' (<code>5 × 8 MJ = 40 MJ</code>).
</div>
</div>

'''BONUS!''' How many [[Mining|mining drills]] are needed to produce that much coal?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Per the linked page, an electric mining drill produces ~0.5/s, so we'll need '''10 electric mining drills''' (<code>10 × 0.5 = 5</code>).
</div>
</div>

Tutorial:Applied power math

2017-03-25T17:54:35Z

Xavier:

{{construction}}

In this tutorial we'll be answering the question: '''how much coal is needed to power our factory?'''

First off, we need to know: how much power does our factory use? That's easy &emdash; you can check the electricity tab by clicking on a power pole.

[[File:power-details.png|800px]]

Here we see one radar using 300kW (the 299kW is a rounding error). Factorio uses real science here. A Watt (W) is a measure of energy transfer. A kilowatt (kW) is 1000 W, a megawatt (MW) is 1000 kW, and if you're lucky enough to ever make a factory big enough, a gigawatt (GW) is 1000 MW.

So that answers the question of how much power our factory uses. To keep our factory running at full speed we need to maintain 300 kW. For ease of comparison, we'll convert that to 0.3 MW

Next question! How much power is stored in coal? That's also easy, because it tells us when we hover over it: 8 MJ.

[[File:coal-joules.png|300px]]

A Joule is another standard measure of stored energy. As with Watts a kilojoule (kJ) is 1000 J, and so on. There is a fixed relationship between Joules and Watts. 1 Joule can provide 1 Watt of energy for 1 second. As a formula:

J = W × s

So to run our factory at 0.3 MW, we need to consume 0.3 MJ every second.

== Quiz ==

Assuming perfect efficiency, how long could one piece of coal (8 MJ) run
our factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = 0.3 MW * s
s = 8 MJ / 0.3 MW
s = 26.67

Nearly 27 seconds.
</div>
</div>

Assuming perfect efficiency, what is the maximum size factory (in watts)
a single piece of coal could run for 5 seconds?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = MW * 5
MW = 8 MJ / 5
MW = 1.6

1.6 megawatts.
</div>
</div>

'''BONUS!''' A ton of real world coal [http://hypertextbook.com/facts/2006/LunChen.shtml|contains about 21 GJ]. How much does a
piece of factorio coal weigh?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
The energy ratios will match the weight ratios, so:

8 MJ / 21000 MJ = weight / 1000 kG
weight = (8 MJ / 21000 MJ) * 1000 kG
weight = 0.38 kG

About 400g! Still doesn't explain how our character can carry so much of it...
</div>
</div>

== Efficiency ==

Let's test it! We should be able to run a radar for 27 seconds, right? Using a setup with a single boiler, steam engine, and radar, we can drop a single piece of coal in the boiler and see how long the radar runs.

[[File:radar-example.png|800px]]

We barely got 20s! What's wrong? We are generating less power than expected.
Let's measure using an accumulator.

[[File:accumulator-example.png|800px]]

We started with 8 MJ in the coal, but only 4 MJ ended up in the accumulator.
This is because, like in the real world, some energy is lost along the way as
waste. In this case, only 50% is making it into our accumulator. In Factorio,
this loss happens in the boiler, and it actually tells us this in the item details! You can think of the waste 50% as going into the pollution it generates...

[[File:boiler-details.jpg]]

Now we have everything we need to answer our initial question: '''how much coal do we need to power our factory?''' Well, the question actually needs to be a bit
more precise: how much coal do we need ''per second'' to power our factory.

<div class="toccolours mw-collapsible mw-collapsed">
'''Aside: why did the radar run for 20s and not 13.5s (50% of 27s)?'''
<div class="mw-collapsible-content">
Because it doesn't turn on and off instantly. As you can see in the graph, it ramps up then ramps down. Technically, if you measured the area under the curve it would give you the expected 4 MJ.
</div>
</div>

== Quiz ==

How much coal per second is needed to power a 20 MW factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Since <code>J = W × s</code>, a 20 MW factory will consume 20 MJ/s. We'll need 40 MJ/s input due to the 50% boiler efficiency loss. Since coal contains 8 MJ, we'll need '''5 coal per second''' (<code>5 × 8 MJ = 40 MJ</code>).
</div>
</div>

'''BONUS!''' How many [[Mining|mining drills]] are needed to produce that much coal?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Per the linked page, an electric mining drill produces ~0.5/s, so we'll need '''10 electric mining drills''' (<code>10 × 0.5 = 5</code>).
</div>
</div>

File:Boiler-details.png

2017-03-25T17:54:30Z

Xavier:

File:Radar-example.png

2017-03-25T17:49:15Z

Xavier:

File:Accumulator-example.png

2017-03-25T17:47:15Z

Xavier:

File:Coal-joules.png

2017-03-25T17:43:46Z

Xavier: Xavier uploaded a new version of File:Coal-joules.png

Tutorial:Applied power math

2017-03-25T17:42:39Z

Xavier:

{{construction}}

In this tutorial we'll be answering the question: '''how much coal is needed to power our factory?'''

First off, we need to know: how much power does our factory use? That's easy &emdash; you can check the electricity tab by clicking on a power pole.

[[File:power-details.png|800px]]

Here we see one radar using 300kW (the 299kW is a rounding error). Factorio uses real science here. A Watt (W) is a measure of energy transfer. A kilowatt (kW) is 1000 W, a megawatt (MW) is 1000 kW, and if you're lucky enough to ever make a factory big enough, a gigawatt (GW) is 1000 MW.

So that answers the question of how much power our factory uses. To keep our factory running at full speed we need to maintain 300 kW. For ease of comparison, we'll convert that to 0.3 MW

Next question! How much power is stored in coal? That's also easy, because it tells us when we hover over it: 8 MJ.

[[File:coal-joules.jpg|800px]]

A Joule is another standard measure of stored energy. As with Watts a kilojoule (kJ) is 1000 J, and so on. There is a fixed relationship between Joules and Watts. 1 Joule can provide 1 Watt of energy for 1 second. As a formula:

J = W × s

So to run our factory at 0.3 MW, we need to consume 0.3 MJ every second.

== Quiz ==

Assuming perfect efficiency, how long could one piece of coal (8 MJ) run
our factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = 0.3 MW * s
s = 8 MJ / 0.3 MW
s = 26.67

Nearly 27 seconds.
</div>
</div>

Assuming perfect efficiency, what is the maximum size factory (in watts)
a single piece of coal could run for 5 seconds?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = MW * 5
MW = 8 MJ / 5
MW = 1.6

1.6 megawatts.
</div>
</div>

'''BONUS!''' A ton of real world coal [http://hypertextbook.com/facts/2006/LunChen.shtml|contains about 21 GJ]. How much does a
piece of factorio coal weigh?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
The energy ratios will match the weight ratios, so:

8 MJ / 21000 MJ = weight / 1000 kG
weight = (8 MJ / 21000 MJ) * 1000 kG
weight = 0.38 kG

About 400g! Still doesn't explain how our character can carry so much of it...
</div>
</div>

== Efficiency ==

Let's test it! We should be able to run a radar for 27 seconds, right? By
dropping a single piece of coal in the burner, we should get our 27 seconds.

[[File:radar-example.youtube]]

We barely got 20s! What's wrong? We are getting less energy than expected.
Let's measure using an accumulator.

[[File:accumulator-example.youtube]]

We started with 8 MJ in the coal, but only 4 MJ ended up in the accumulator.
This is because, like in the real world, some energy is lost along the way as
waste. In this case, only 50% is making it into our accumulator. In Factorio,
this loss happens in the boiler, and it actually tells us this in the item details! You can think of the waste 50% as going into the pollution it generates...

[[File:boiler-details.jpg]]

Now we have everything we need to answer our initial question: '''how much coal
do we need to power our factory?''' Well, the question actually needs to be a bit
more precise: how much coal do we need ''per second_' to power our factory.

== Quiz ==

How much coal per second is needed to power a 20 MW factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Since <code>J = W × s</code>, a 20 MW factory will consume 20 MJ/s. We'll need 40 MJ/s input due to the 50% boiler efficiency loss. Since coal contains 8 MJ, we'll need '''5 coal per second''' (<code>5 × 8 MJ = 40 MJ</code>).
</div>
</div>

'''BONUS!''' How many [[Mining|mining drills]] are needed to produce that much coal?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Per the linked page, an electric mining drill produces ~0.5/s, so we'll need '''10 electric mining drills''' (<code>10 × 0.5 = 5</code>).
</div>
</div>

File:Coal-joules.png

2017-03-25T17:41:18Z

Xavier:

File:Power-details.png

2017-03-25T17:38:19Z

Xavier:

Tutorial:Applied power math

2017-03-25T17:30:36Z

Xavier:

{{construction}}

In this tutorial we'll be answering the question: '''how much coal is needed to power our factory?'''

First off, we need to know: how much power does our factory use? That's easy &emdash; you can check the electricity tab by clicking on a power pole.

[[File:power-details.jpg]]

Here we see one radar using 300kW (the 299kW is a rounding error). Factorio uses real science here. A Watt (W) is a measure of energy transfer. A kilowatt (kW) is 1000 W, a megawatt (MW) is 1000 kW, and if you're lucky enough to ever make a factory big enough, a gigawatt (GW) is 1000 MW.

So that answers the question of how much power our factory uses. To keep our factory running at full speed we need to maintain 300 kW. For ease of comparison, we'll convert that to 0.3 MW

Next question! How much power is stored in coal? That's also easy, because it tells us when we hover over it: 8 MJ.

[[File:coal-joules.jpg]]

A Joule is another standard measure of stored energy. As with Watts a kilojoule (kJ) is 1000 J, and so on. There is a fixed relationship between Joules and Watts. 1 Joule can provide 1 Watt of energy for 1 second. As a formula:

J = W × s

So to run our factory at 0.3 MW, we need to consume 0.3 MJ every second.

== Quiz ==

Assuming perfect efficiency, how long could one piece of coal (8 MJ) run
our factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = 0.3 MW * s
s = 8 MJ / 0.3 MW
s = 26.67

Nearly 27 seconds.
</div>
</div>

Assuming perfect efficiency, what is the maximum size factory (in watts)
a single piece of coal could run for 5 seconds?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = MW * 5
MW = 8 MJ / 5
MW = 1.6

1.6 megawatts.
</div>
</div>

'''BONUS!''' A ton of real world coal [http://hypertextbook.com/facts/2006/LunChen.shtml|contains about 21 GJ]. How much does a
piece of factorio coal weigh?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
The energy ratios will match the weight ratios, so:

8 MJ / 21000 MJ = weight / 1000 kG
weight = (8 MJ / 21000 MJ) * 1000 kG
weight = 0.38 kG

About 400g! Still doesn't explain how our character can carry so much of it...
</div>
</div>

== Efficiency ==

Let's test it! We should be able to run a radar for 27 seconds, right? By
dropping a single piece of coal in the burner, we should get our 27 seconds.

[[File:radar-example.youtube]]

We barely got 20s! What's wrong? We are getting less energy than expected.
Let's measure using an accumulator.

[[File:accumulator-example.youtube]]

We started with 8 MJ in the coal, but only 4 MJ ended up in the accumulator.
This is because, like in the real world, some energy is lost along the way as
waste. In this case, only 50% is making it into our accumulator. In Factorio,
this loss happens in the boiler, and it actually tells us this in the item details! You can think of the waste 50% as going into the pollution it generates...

[[File:boiler-details.jpg]]

Now we have everything we need to answer our initial question: '''how much coal
do we need to power our factory?''' Well, the question actually needs to be a bit
more precise: how much coal do we need ''per second_' to power our factory.

== Quiz ==

How much coal per second is needed to power a 20 MW factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Since <code>J = W × s</code>, a 20 MW factory will consume 20 MJ/s. We'll need 40 MJ/s input due to the 50% boiler efficiency loss. Since coal contains 8 MJ, we'll need '''5 coal per second''' (<code>5 × 8 MJ = 40 MJ</code>).
</div>
</div>

'''BONUS!''' How many [[Mining|mining drills]] are needed to produce that much coal?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Per the linked page, an electric mining drill produces ~0.5/s, so we'll need '''10 electric mining drills''' (<code>10 × 0.5 = 5</code>).
</div>
</div>

Tutorial:Applied power math

2017-03-25T17:29:48Z

Xavier: Created page with "{{construction}} In this tutorial we'll be answering the question: '''how much coal is needed to power our factory?''' First off, we need to know: how much power does our fa..."

{{construction}}

In this tutorial we'll be answering the question: '''how much coal is needed to power our factory?'''

First off, we need to know: how much power does our factory use? That's easy &emdash; you can check the electricity tab by clicking on a power pole.

[[File:power-details.jpg]]

Here we see one radar using 300kW (the 299kW is a rounding error). Factorio uses real science here. A Watt (W) is a measure of energy transfer. A kilowatt (kW) is 1000 W, a megawatt (MW) is 1000 kW, and if you're lucky enough to ever make a factory big enough, a gigawatt (GW) is 1000 MW.

So that answers the question of how much power our factory uses. To keep our factory running at full speed we need to maintain 300 kW. For ease of comparison, we'll convert that to 0.3 MW

Next question! How much power is stored in coal? That's also easy, because it tells us when we hover over it: 8 MJ.

[[File:coal-joules.jpg]]

A Joule is another standard measure of stored energy. As with Watts a kilojoule (kJ) is 1000 J, and so on. There is a fixed relationship between Joules and Watts. 1 Joule can provide 1 Watt of energy for 1 second. As a formula:

J = W × s

So to run our factory at 0.3 MW, we need to consume 0.3 MJ every second.

== Quiz ==

Assuming perfect efficiency, how long could one piece of coal (8 MJ) run
our factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = 0.3 MW * s
s = 8 MJ / 0.3 MW
s = 26.67

Nearly 27 seconds.
</div>
</div>

Assuming perfect efficiency, what is the maximum size factory (in watts)
a single piece of coal could run for 5 seconds?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
8 MJ = MW * 5
MW = 8 MJ / 5
MW = 1.6

1.6 megawatts.
</div>
</div>

'''BONUS!''' A ton of real world coal [http://hypertextbook.com/facts/2006/LunChen.shtml|contains about 21 GJ]. How much does a
piece of factorio coal weigh?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
The energy ratios will match the weight ratios, so:

8 MJ / 21000 MJ = weight / 1000 kG
weight = (8 MJ / 21000 MJ) * 1000 kG
weight = 0.38 kG

About 400g! Still doesn't explain how our character can carry so much of it...
</div>
</div>

== Efficiency ==

Let's test it! We should be able to run a radar for 27 seconds, right? By
dropping a single piece of coal in the burner, we should get our 27 seconds.

[[File:radar-example.youtube]]

We barely got 20s! What's wrong? We are getting less energy than expected.
Let's measure using an accumulator.

[[File:accumulator-example.youtube]]

We started with 8 MJ in the coal, but only 4 MJ ended up in the accumulator.
This is because, like in the real world, some energy is lost along the way as
waste. In this case, only 50% is making it into our accumulator. In Factorio,
this loss happens in the boiler, and it actually tells us this in the item details! You can think of the waste 50% as going into the pollution it generates...

[[File:boiler-details.jpg]]

Now we have everything we need to answer our initial question: '''how much coal
do we need to power our factory?''' Well, the question actually needs to be a bit
more precise: how much coal do we need ''per second_' to power our factory.

== Quiz ==

How much coal per second is needed to power a 20 MW factory?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Since <code>J = W × s</code>, a 20 MW factory will consume 20 MJ/s. We'll need 40 MJ/s input due to the 50% boiler efficiency loss. Since coal contains 8 MJ, we'll need 5 coal per second (<code>5 × 8 MJ = 40 MJ</code>).
</div>
</div>

'''BONUS!''' How many [[Mining|mining drills]] are needed to produce that much coal?

<div class="toccolours mw-collapsible mw-collapsed">
'''Expand to reveal answer'''
<div class="mw-collapsible-content">
Per the linked page, an electric mining drill produces ~0.5/s, so we'll need 10 electric mining drills (<code>10 × 0.5 = 5</code>).
</div>
</div>

User:Xavier

2017-03-25T16:58:27Z

Xavier:

Launching rockets since 0.13. Yuoki's mods are the best mods. Trains for life. Solar sucks.

Australian living in San Francisco.

I stream sometimes at https://www.youtube.com/channel/UC8-DvIU3okeUS44vrGDNUPg

Personal website at https://xaviershay.com

<blockquote>
"If you keep proving stuff that others have done, getting confidence, increasing the complexities of your solutions - for the fun of it - then one day you'll turn around and discover that nobody actually did that one!" - Richard Feynman
</blockquote>