EU

A BatBox receiving EU from an RE Battery.

EU, which stands for Energy Unit, is the measure of energy production, consumption, transmission and storage in IndustrialCraft.

These units are not similar to actual real life electricity; they are "virtual" items, that can stack unlimited amount of times and need storage items like RE Batteries or a cable network be used. EU stored in items or devices will not decay over time.

Every IndustrialCraft 2 machine is involved in the production, storage, or consumption of EU.

EU is not related to Redstone current, but multiple machines can be affected by redstone currents, and a Detector Cable produces a current if there is any EU passing through it. Some machines allow a lever to be mounted directly on its block.

Raw EU values are used to measure capacity of energy storage items or blocks.

EU/t

EU/t means Energy unit per tick. If the computer or server is able to handle all ingame calculations, the game will operate at about 20 ticks per second. If this is not the case, the clockrate will drop significantly and you will notice ingame time slowdown. If the clockrate is 10, a second in game will last as long as 2 IRL seconds.

EU/t is used to measure EU consumption and production, EU/t can be measured with an EU-Reader by clicking on any cable two times with some delay.

EU-Packet / Voltage

EU-Packets are the transmission containers of EUs. They represent voltage in Industrial Craft 2.

EU-Packets come in different sizes ranging from 1 EU to 2048 EU, unlike IC1 you may not change EU output of storage devices.

Multiple EU-Packets can pass through a cable at any given time. For example, if you have 5 generators running at the same and you measure the line going into a Bat Box, assumin no EU loss, the reader will show 50 EU/t. From this reading, one would assume that the BatBox should explode since it has a maximum input of 32 EUt. This is becaus the EU is being sent as 5 seperate packets of 10EU each. The max input refers to the maximum packet size and not the total amount of EU. In theory, it is possible to charge a BatBox in 1 second by hooking up 200 generators with Glass Fibre Cable.

Storage devices and transformers with a redstone current applied output 1 EU-Packet of its respective tier, while transformers without redstone current will output enough EU-Packets to not blow up machines of the same tier, but the total amount of EU passing through the cable will not change. In the same example as before, one could charge a BatBox in .97 seconds with a large Nuclear Reactor outputting 2048 EU/t if there is an LV Transformer between them.

Note that energy loss calculated for a cable is on a per packet basis, therefore, you would lose 6400% more power transfering 2048 EU/t in low voltage than in high voltage while using the same cable. You will find your large quantities of power are best transfered by stepping down from extreme to high voltage, then using Glass Fibre Cable.

There is no way to measure what size of packets travels through a cable or machine without an EU-Reader but they can be read from EU emitting blocks.

Emitters such as Generators, Storage Units, and Transformers can emit EU-Packets.

Emitters

Generators emit packets as large as their output.
Storage Units always emit packets the size of their "out" value.
Transformers behave like Storage Units. They are also able to upgrade four packets into one of a higher tier or downgrade a single packet into four of a lower tier, depending on input or output.

Cables

Cables can carry unlimited amounts of EU/t but only EU-Packets that are the same or below of their maximum Voltage. You can send unlimited amounts of 32 EU-Packets through a Copper cable but not a single 128 EU-Packet. The clue is that energy loss of a cable isn't connected to the total amount of EU/t but to every single packet. So sending 100 32 EU-Packets results in 100 times the energy loss of the cable where sending one 2048 EU-Packet only result in one time the energy loss of the cable.

Nuclear Reactor

A Nuclear Reactor is able to provide power of variable "Voltage" based on setup. The maximum possible energy output is 2040 EU\t (without burning the wire). However, note that it can not provide any less than 10EU/packet, as that is the output of a single Uranium Cell.

Packet Sizes

Name	Packet Size	Emitters	Cable
Micro Voltage	0-5 EU	Solar Panel, Water Mill, Wind Mill	File:Grid Tin Cable.png			File:Grid Glass Fibre Cable.png	File:Grid HV Cable.png
Low Voltage	32 EU	BatBox, LV Transformer, Generator, LV Solar Array			File:Grid Glass Fibre Cable.png	File:Grid HV Cable.png
Medium Voltage	128 EU	MFE Unit, MV Transformer, Redstoned LV Transformer, Nuclear Reactor, MV Solar Array		File:Grid Glass Fibre Cable.png	File:Grid HV Cable.png
High Voltage	512 EU	MFS Unit, HV Transformer, Redstoned MV Transformer, Nuclear Reactor, HV Solar Array	File:Grid Glass Fibre Cable.png	File:Grid HV Cable.png
Extreme Voltage	2048 EU	Redstoned HV Transformer, Nuclear Reactor	File:Grid HV Cable.png