What is Retro Energy?
Retro Energy is a Special Energy that was used in the Pokémon Trading Card Game (TCG). It has only been released once – in the Skyridge set of 2003.
See also: What are Special Energy Cards?
The Retro Energy card provides two Colorless Energy but can only be attached to an Evolved Pokémon. The card design features one Colorless Energy symbols.
In the Pokémon TCG, a player can only use an Attack Move if the specified number of Energy are attached. This specified number generally includes one or more Energy that corresponds to the Pokémon type, and / or a number of Colorless Energy. Retro Energy Cards provide one Colorless Energy or one of any Energy attached to that Pokémon.
Retro Energy Card Text:
The text on the card reads: ‘This card provides 
Energy. You can attach this card to your Pokémon that has basic Energy cards attached to it.
When you play this card from your hand and attach it to 1 of your Pokémon, return a basic Energy card attached to that Pokémon to your hand.’
Gallery
Retro Energy Card 144/144 from Skyridge
