In engineering, there are different design objectives for heat pump systems, such as the maximum coefficient of performance, the maximum net heat flow rate into the high temperature heat source and the best thermo-economic performance. As such, the authors provide a comprehensive overview of heat pump technology, focusing on system design, performance, optimization and applications associated with this technology. Following this, a research study on the optimal operation of a power system in the presence of renewable sources is presented, considering two objectives: decreasing power losses and improving the voltage level in the nodes of the electric network. A method for detecting short-path wormhole tunnels rather than relying solely on topological features of the network is described. In a wormhole attack, the malicious nodes generally work in pairs and set up a high-speed tunnel for long distances between them. An approach to multi-objective optimization techniques is presented and applied to either subtractive or additive manufacturing processes. Additionally, the suitability of multi-objective optimization methods is depicted through a case study related to the selective laser melting process. The performance evaluation of the binary heap tree-based discrete particle swarm optimization is presented and compared with existing Pareto dominance-based multi-objective techniques such as non-dominated sorting genetic algorithm-II and non-dominated sorting particle swarm optimization. In closing, the authors present a problem that highlights the influence that bidirectional power flows may have on solutions regarding the optimal allocation of energy storage systems in real microgrids in the developing country of Romania.