Graph-Based Optimization for Technology Pathway Analysis: A Case Study in the Decarbonization of University Campuses

Industrial sectors, such as urban centers, chemical companies, manufacturing facilities, and microgrids, are actively exploring strategies to help reduce their carbon footprint. For instance, university campuses are complex urban districts (involving collections of buildings and utility systems) that are seeking to reduce carbon footprints, which originate from diverse activities (e.g., transportation operations and production of heating, cooling, and power utilities). This work presents an optimization framework to identify technology pathways that enable the decarbonization of complex industrial sectors. The framework uses a graph abstraction that compactly captures interdependencies between diverse products and technologies as well as diverse externalities (e.g., market, policy, and carbon prices). Duality analysis reveals that the formulation can be interpreted as an economy, market, or value chain that uses technologies to generate economic value (wealth) by transforming basic products into higher-value products. This interpretation also reveals that the formulation identifies pathways, which maximize the profit of stakeholders, helps reveal the inherent value (prices) of intermediate products, and analyzes the impact of externalities and technology specifications on product values. Our developments are illustrated via a case study involving a prototypical university campus that seeks to identify pathways that reduce its carbon footprint (e.g., via electrification and the deployment of hydrogen technologies). We use the framework to determine carbon tax values, technology specifications, and investment budgets that activate different technology pathways and achieve different levels of decarbonization. © 2024 American Chemical Society.