Since version 5.0 (for Minecraft 1.7.2) GregTech has its own Energy System since GregoriusT was not 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 Energy Hatches. Machine and recipe tiers do interact, and must be paid attention to.
- 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.
Recipes can be overclocked multiple times if a machine is more than one tier above a recipe's tier.
GregTech has 10 Voltage Tiers as of version 5.0.
Note: ULV Tier counts as Tier 0.
|ULV||Ultra Low Voltage||8|
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 Transformer (Not to be confused with the IC2 Transformer).
All GT Cables have a max Voltage, max Amperage and a 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.
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.
- The loss of a cable is per Block a EU package travels.
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.
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:
|Material||Max Voltage||1x Insulated Cable Max Amp||Loss/m/amp/tick in EU||Efficiency compared to Tin Wire||Length until 0 Power||Most efficient number of Cables between Batteries|
|Yttrium Barium Cuprate||32768||4||4||256.00||8192||475.2|
|Naquadah Alloy (GT5U)||524288||2||4||4,096.00||131072||-|
(*No insulated Cable version) (**No crafting recipe yet)
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).
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:
|Tier||Output||Loss||Loss in %||Energy used|
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=<Insert tier here>, L=<Insert Cable loss here>". 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.
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.
GregTech machines does not accept EU from IndustrialCraft² cables and some other mods EU powered blocks does not accept GregTech cables, thus there is the need to convert IC2 EU and GT5 EU back and forth.
To convert IC2 EU into GT5 EU, simply connect (read put directly adjacent) a GT transformer input to an IC2 Energy Source output side. This means connecting the output dot of a IC2 transformer/storage block to the input dot of a GT transformer.
To convert GT5 EU into IC2 EU, simply connect GT cables to IC2 blocks.
Example screenshots of IC2 and GT5 EU conversions: