Essentia is not liquid energy (that's the vis, which comes from nodes), but magical aspect, which are something like a description, affinity, or makeup. Also, what i meant is for the other dynamos to be able to consume a verity of essence to increase their speed and efficiency so that most essentia would have a use in the other three engines.
(Golem dynamos, for example, taking Cognito, fabrico, lucrum, etc for efficiency, iter, instrumenum, bestia, etc for power, the golem's own material (flesh-corpus, wood-arbor) for golem durability, humanos for all, or thaumotive dynamo taking ignis, potentia, precantatio, motus, herba, arbor, etc for power, ordo, permutatio, machina, tempus, etc for efficiency... )