<p>Energy sector planning through Resource Conservation Networks (RCN) is crucial for sustainability. Integrating renewable and new technologies is key to sustainability, but it often challenges cost optimality. Pinch analysis identifies the cost-optimal solution in the energy sector through RCNs. In Pinch analysis, RCNs involving multiple resources are addressed using the prioritized cost. Prioritized costs of resources determine whether a resource is part of the optimal solution. The prioritized cost is necessary but insufficient for the cost-optimal solution. In RCNs involving at least three resources, it is possible to replace some of the resources with a combination of other resources to obtain the cost-optimal solution. This work identifies the replacement criterion of resources as an additional condition to achieve optimality. A methodology, combining the replacement and prioritized cost conditions for targeting multiple resources using Pinch analysis, is proposed in this paper. A new graphical representation, a cost-quality diagram, is introduced in this paper to enhance the physical understanding of the energy sector planning. Using the proposed methodology, optimal energy systems are identified using renewable and non-renewable resources. The method’s applicability is demonstrated using examples from the energy sector planning involving carbon footprint, land footprint, and emergy transformity.</p> Graphical abstract