Developer Artist Guidelines

IC2Classic has a official Energy Tier naming/power list for its power tiers.
This is the actively used list that is final in its naming Sceme.

Short	Name	Max Voltage	Primary Cable	Input/Output Colors	Tier Color
ULV	Ultra Low Voltage	8	Tin Cable	N/A	N/A
LV	Low Voltage	32	Copper Cable	$\color{#A05E1D}{\text{0xA05E1D}}$	$\color{#1EC719}{\text{0x1EC719}}$ (Plantball)
MV	Medium Voltage	128	Gold Cable	$\color{#FFEF00}{\text{0xFFEF00}}$	$\color{#D52929}{\text{0xD52929}}$ (Redstone)
HV	High Voltage	512	Glassfiber Cable	$\color{#FFFFFF}{\text{0xFFFFFF}}$	$\color{#1F69D8}{\text{0x1F69D8}}$ (Lapis)
EV	Extreme Voltage	2.048	Iron Cable	$\color{#AAC4C8}{\text{0xAAC4C8}}$	$\color{#D8E11C}{\text{0xD8E11C}}$ (Glowstone)
IV	Insane Voltage	8.192	Aluminium Cable	$\color{#ECEDE3}{\text{0xECEDE3}}$	$\color{#EF1BEC}{\text{0xEF1BEC}}$ (UU-Matter)
LuV	Ludicrous Voltage	32.768	Plasma Cable	$\color{#29BBB5}{\text{0x29BBB5}}$	N/A (Plasma Core)

Greg/GT did provided its own Energy Tier List.
While the Max Voltage numbers are correct.
The names are not. They are subject to change.

Short	Name	Max Voltage
ZPM	ZPM Voltage	131.072
UV	Ultimate Voltage	524.288
UHV	Highly Ultimate Voltage	2.097.152
UEV	Extremely Ultimate Voltage	8.388.608
UIV	Insanely Ultimate Voltage	33.554.432
UMV	Mega Ultimate Voltage	134.217.728
UXV	Extended Mega Ultimate Voltage	536.870.912