Širovnik D., Zore Ž., Cucek L., Pintaric Z., Kravanja Z., 2016, System Synthesis by Maximizing Sustainability Net Present Value, Chemical Engineering Transactions, 52, 1075-1080.
This contribution presents a new concept for multi-objective systems synthesis which is based on a composite sustainability measurement called sustainability net present value (SNPV). This is an extension of the recently developed metric sustainability profit (Zore et al., 2016). SNPV is a metric composed of economic, environmental and social efficiency, expressed in monetary terms and is defined from the wider macro- economic perspective as well as from an individual company’s micro-economic view. By using SNPV, it is possible to obtain answer regarding the advisability of a particular investment in terms of sustainability. The presented concept is illustrated by two examples of biofuel supply networks: i) a company’s supply network for existing biogas production, and ii) a larger-scale biofuel supply network. Both burdening and unburdening alternatives were considered in the comparative study. Maximal SNPV occurs at the appropriate trade-off between economic, environmental and social aspects and yields a solution with alternatives selected in order to provide the highest economic profitability, environmental unburdening and new job opportunities, considering the time value of the money involved.