From The Dim Future Wiki

Costs in the game are paid in energy. There are 3 separate kinds of energy Electric (Electric), Protein (Protein), and Lay (Lay). The kinds of energy separate, but are treated identically.

Energy is stored in pools. One for each kind of energy. The pools will store energy indefinitely and will not recharge on their own.

Costs are often a combination of these. Costs are most often payed when a card is played or during the restore phase. However cards can force or allow characters to pay other costs. A cost is payed by simply deducting the amount of energy required from the player's pools.