Design of an emergy-based model for economic and environmental sustainability of energy supply chains

• Main Author: Felix, Nathaniel Isidore B.
• Format: text
• Language: English
• Published: Animo Repository 2011
• Subjects: Renewable energy sources; Power resources; Energy Systems; Industrial Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/6491; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/12992/viewcontent/CDTG004940_P.pdf
• Institution: De La Salle University

Energy supply chains have a huge importance in today’s economy and powers both the industry and households around the world. Designing energy supply chains optimizes strategic development within the industry. Despite its importance, there have been few studies tackling the issue of sustainability when designing the energy supply chain. Sustainability, the ability to meet current needs without compromising the needs of the future, is said to be a function of yield, renewability of resources and load on the environment. Common energy supply chain studies cover yield, having the ability to suffice demand but ignore the other two aspects that define a supply chain’s sustainability. Emergy, a measure that covers both the work of nature and that of humans in generating products and services, enables the ability to bridge the gap of identifying and assessing systems according to their load on the environment and the renewability of resources. A mathematical model was developed to cover both economic performance and environmental impact in the energy supply chain by minimizing total cost and total emergy respectively. Almansoori & Shah’s (2009) model was used as a base model and translated through GAMS together with additional enhancements to cover the environmental facet of the energy supply chain. Pareto-optimal solutions were developed to assess the trade-off between economic performance and environmental impact. A case study of the hydrogen supply chain used in Almansoori & Shah’s (2009) study was also employed to test the model’s efficacy. Based from the results, the network was originally dependent on nonrenewable resources and had a large total emergy value; but by minimizing emergy, the model shifted from being natural gas dependent, to using renewable electricity to produce its hydrogen requirements. Emergy value dropped however total cost increased significantly. Budget constraints and emergy indicator constraints were introduced to reach a design that balanced both economic and environmental aspect. From the study, it was concluded that the current network solutions that did not account for load on the environment and the renewability of resources, made decisions that has the worst value for both the load and the renewability. By introducing emergy, the supply chain was configured to a more sustainable one. However, this came with a price of increased cost. It is indeed possible to make a sustainable energy supply chain, but there is always an apparent trade-off between the environmental and economic aspect. The question that begs to be answered is, “How much are you willing to give up for?