Electricity

Since version 5.0 (for Minecraft 1.7.2) GregTech has its own Energy System since GregoriusT wasn't satisfied with IC2 Experimental's Energy System.

Voltage and Amperage
GregTech uses the terms Voltage (V) and Amperage (A) to describe its new Power system. One "Amp" is roughly the same as one EU Packet from IC2, and "Voltage" is the size of that packet.

EU/t is the total EU received. For example, if a machine receives one 32V packet and another 24V packet, the total EU/t received is 32 + 24 = 56 EU/t.

Unlike the IC2 energy system, all GregTech energy-interacting blocks have limits on both the Voltage and the Amperage they can interact with.

Different machine blocks accept and emit different Amperages.
 * GregTech Transformers will input 4A and output 1A if used to step-up Voltages; they will input 1A and output 4A if used to step-down.
 * Battery Buffers input 2A per Battery and output 1A per Battery.
 * Battery Chargers input 8A per Battery and output 4A per Battery.
 * Chest Buffers and Super Buffers accept 2A.
 * Energy Hatches accept 2A input.
 * Mass Fabricators accept 10A input.
 * Microwave Energy Transmitters accept 3A input.
 * Monster Repellators, Pumps, and Teleporters accept 2A input.
 * All other EU accepting machine blocks accept at least 1A, depending on recipe: The amperage is equal to twice the recipe's EU usage, divided by the machine's voltage input, rounded down and added to 1.
 * An LV Centrifuge performing a 5 EU recipe accepts 1A
 * An LV Chemical Reactor performing a 30EU recipe accepts 2A
 * An LV Arc Furnace performing a 96EU recipe accepts 7A
 * Generators output 1A.

You do need to be careful when trying to power machines:
 * Machines that get a higher Voltage than they can handle explode. Machines will not receive voltage until they need it, so the machine may not actually explode until it begins working!
 * Excess Amperes fed into machines have no effect as long as the voltage is below the machines' limit. A machine will not draw current unless it needs power, and it will not draw fractions of an ampere. This makes machines self-regulating with regards to power.

Machines and recipes each have voltage tiers. The tier of a Multiblock Machine is determined by its. Machine and recipe tiers do interact, and must be paid attention to.

Recipes will be overclocked once per Voltage Tier difference between the machine's supplied Voltage Tier and the recipe's required one. If a recipe requiring 30 EU/t (LV tier) for 20 seconds is performed in an HV machine, the difference of 2 tiers will cause the recipe to use 480 EU/t for 5 seconds.
 * If a recipe has a minimum required voltage within a higher tier than that of the machine, the recipe cannot be carried out.
 * If a recipe has a minimum required voltage within the same tier as the machine, the recipe functions normally.
 * If a recipe has a minimum required voltage within a lower tier than that of the machine, the recipe is overclocked. Overclocked recipes are carried out at double normal speed, double normal total energy, and thus quadruple normal energy per tick.

GregTech: New Horizons has 9 finished Voltage Tiers as of version 2.0.2.5, it also has 3 Voltage Tier partial finished voltage levels(*) and 3 not reachable voltage levels(**).

Note: ULV Tier counts as Tier 0.

Cables and Loss
Given that GregTech has its own power system now, you will need to use GT cables for powering GT machines. Do note that the only machine capable of accepting IC2 EU in GT is the [[GT5U Transformer|Transformer}} (Not to be confused with the IC2 Transformer).

All GT Cables have a max Voltage, max Amperage and a Loss: Do note that packets can rebound. Even if the logical path that a packet dictates that EU should not travel in that direction, you should not take for granted that your cables will not have some stray EU packets travelling through them. For example a 32V package is sent trough a Tin Cable which has a loss of 1EU per block to a machine 8 blocks away. After 8 blocks of cables the 32V Package is down to 24V when it arrives at the machine. Should the machine need for example 30EU/t to operate. A second package sent in the same tick is needed every 4 Ticks. Thus a 2A supply is needed for the machine with this setup. Cable losses are applied to each EU Package, netting you a 2x power loss.
 * Cables that get packets higher than their maximum Voltage will catch fire and melt.
 * Cables that have more Amperes travelling through them than their maximum Amperage limit will catch fire and melt.
 * The loss of a cable is per Block a EU package travels.

Each Material has 1x, 2x, 4x, 8x 12x and 16x uninsulated Wires and 1x, 2x, 4x, 8x and 12x Insulated Cables.

Do note that Uninsulated Wires have 2x the loss as Insulated Cables.

Here is an example:
 * A 1x Tin Cable can handle 1A and 32V at a loss of 1V/m. This means that the EU packet can travel 32 blocks before it dies.
 * A 1x Tin Wire can handle 1A and 32V at a loss of 2V/m. In this case, the EU can travel 16 blocks only.

Below is a table of the current properties of various types of cables in GregTech:

(*No insulated Cable version)

Also any GT Block and Battery outputting Energy has an energy loss on output. This means there is no such thing as lossless cables in GregTech.

A power outputting machine will take (8 * 4 ^ Tier) + (2 ^ Tier) EU from its storage and output only (8 * 4 ^ Tier) EU. The energy lost is therefore (2 ^ Tier).

An example: Say a turbine is supposed to output 32V.

output = 32 = (8 * 4 ^ Tier).

Solving for Tier gives you 1. The energy loss will then be (2 ^ Tier). In this case it is 2.

So the turbine takes 34 EU from its storage, voids 2 EU per packet and then outputs 32 EU.

Here is a table documenting some of the cable properties in GregTech:

Optimal Cable length between Batteries for maximum efficiency.

The EU loss of GregTech Cables and Batteries scales linearly with the number of sequential Cables and the number of Batteries, but since voltage is topped up at every battery there will be a loss that is increasing exponentially for every identical segment of a Battery and x-number of Cable links. This exponential loss from more batteries also reduces the impact of the linear loss, but this ofc comes at the cost of more exponential loss. This means that there must exist a sweet spot, because with short segments the extra exponential loss of more segments will be more detrimental to the efficiency than the linear loss from making each segment longer, for long segments this will be reversed. So lets do the math!

Lets first define our terms, a segment is the length of a Battery plus a number of sequential Cables. The efficiency of such a segment will be (8 * 4^T - (D - 1)L) / (8 * 4^T + 2^T). T is the tier (ULV is tier 0, LV is tier 1 and so on). L is the loss of the cable in voltage/meter/ampere. D is the distance of the segment, so the length of the Cables plus the battery.

But this is no good since we want to figure out the optimal length when there is an element of exponential decline that we haven't accounted for. We do this by making an expression of how much efficiency we get in each single block if there was a uniform exponential decline over the whole segment. This turns out to be ((8 * 4^T - (D - 1)L) / (8 * 4^T + 2^T))^(1 / D).

We now take the derivative of that expression with respect to D to get how the efficiency changes when we change the length of the segments, when we do this we get such a ghastly monstrosity that not even WolframAlpha can deal with it algebraically. But this wont stop us on our quest for efficiency! Lets solve it numerically!

Step 1: go to http://www.wolframalpha.com/ because we are lazy. Step 2: Enter "(d/dD) ((8 * 4^T - (D - 1)L) / (8 * 4^T + 2^T))^(1 / D) = 0, T=, L=". It will solve the problem numerically for each separate case. So if you want to know the optimal length of Annealed Copper Cable between your MV Batteries, you enter T=2, L=1 and it will give you the optimal length of each segment (This includes the battery!). In the case of Annealed Copper Cable this turns out to be about 24.1, so 23 cables between each battery is optimal. For more information on other cables, see the table above.

Transformers
Once you have crafted your first EBF and started MV tier, you will gain access to producing MV (Medium Voltage, 128V) which is great! However. You will need to transform this energy into LV power to use it with your existing LV machines since LV Machines will explode if they are given too high voltage.

The Transformer allows you to convert GT Energy between voltage tiers. The big hollow circle is the Higher voltage side and is the front of the transformer, while the 5 smaller circles are the lower voltage sides.

By default the Transformer is taking 1 amp of higher voltage and transforms it into 4 amps of lower voltage. This is also called Step-Down mode. Ingame it will say “Machine Active” when toggling to this mode. You can also right click the transformer with a Soft Mallet to switch between its two modes. In Inverted mode, Step-Up mode (“Machine Inactive”), the Transformer will take 4 amps of lower Voltage and transform it into 1 amp of Higher voltage. Keep in mind that in this mode the lower voltage sides become the Input, and the higher voltage side is therefore the Output.

You should never change mode on a transformer that has power. Always disconnect cables before switching mode on the Transformers.

Power Transformer and Hi-Amp Transformer
The Power Transformer and the Hi-Amp Transformer work like an ordinary transformer with one exception:

The Hi-Amp Transformer will accept 4 amps of higher voltage and turn it into 16 amps of lower voltage in its default mode. In inverted mode it will transform 16amps lower voltage to 4 amps of higher voltage.

The Power Transformer will accept 16 amps of higher voltage and turn it into 64 amps of lower voltage in its default mode. In inverted mode it will transform 64 amps lower voltage to 16 amps of higher voltage.

Machine explosions and cables burning
Using GregTech machines without thought and care can be fairly unsafe. If a machine gets contact with rain on any of the 6 sides of the block, it can catch fire. If a machine gets lit on fire, it can explode. If a wire exceeds its current rating, it will catch on fire.

When using battery buffers, be sure to watch the output and input amps. Be careful when distributing power from one battery buff to another battery buff further away. The destination battery buff will pull 2A per battery. If the source battery buff has more batteries than the power cable can handle, the cable will catch fire. One way to prevent excessive current from a battery buffer output is to limit the number of batteries in the buffer to the amperage of the cable. 1 batt can output 1A. If you need to store more power, you place a large, x16 battery buff next to smaller battery buff, such as a x4, that is connected to your distribution cable. This will let you store 20 batts of power and safely output 4A of power. You can expand power storage by placing additional x16 batt buffs against the x4. Just remember, if you need to place a wire between them, it needs to be at least an 8 A wire!

Energy conversions
GregTech energy and IC2 energy are not the same. So GregTech energy systems cannot automatically use IC2 energy, and thus need to be converted, and vis versa.

To convert IC2 EU into GT EU, connect (directly adjacent) a GT Transformer's input face to an IC2 Energy Source's output face. This means connecting the output dot of a IC2 transformer/storage block to the input dot of a GT Transformer.

To convert GT EU into IC2 EU, connect GT cables to IC2 blocks