As economies become increasingly complex, so do their associated energy generation systems. Therefore, engineers and decision makers in this sector are spurred to seek out state-of-the-art approaches to deal with this rapid increase in system complexity. An effective strategy to deal with this scenario is to employ computational intelligence (CI) methods. CI supplements the heuristics used by the engineer—enhancing the cumulative analytic capacity to effectively resolve complicated scenarios. CI could be split to two classes: predictive modeling and optimization. In this chapter, past applications of CI in energy generation are discussed. The sectors presented here are renewable energy systems, distributed generation, nuclear power plants, coal power, and gas-fueled plants.