A Nexus Approach for Sustainable Urban Energy-Water-Waste Systems Planning and Operation

Abstract

Energy, water, and waste systems analyzed at a nexus level are important to move toward more sustainable cities. In this paper, the "resilience.io" platform is developed and applied to emphasize on waste-to-energy pathways, along with the water and energy sectors, aiming to develop waste treatment capacity and energy recovery with the lowest economic and environmental cost. Three categories of waste including wastewater (WW), municipal solid waste (MSW), and agriculture waste are tested as the feedstock for thermochemical treatment via incineration, gasification, or pyrolysis for combined heat and power generation, or biological treatment such as anaerobic digestion (AD) and aerobic treatment. A case study is presented for Ghana in sub-Saharan Africa, considering a combination of waste treatment technologies and infrastructure, depending on local characteristics for supply and demand. The results indicate that the biogas generated from waste treatment turns out to be a promising renewable energy source in the analyzed region, while more distributed energy resources can be integrated. A series of scenarios including the business-as-usual, base case, naturally constrained, policy interventions, and environmental and climate change impacts demonstrate how simulation with optimization models can provide new insights in the design of sustainable value chains, with particular emphasis on whole-system analysis and integration.

Planning of Food-Energy-Water-Waste (FEW2) nexus for sustainable development

“…These scenarios can be designed to reflect policy changes, regional connections, economic background and advances in technologies, while providing insights on the optimal solutions of long-term development, that is, to meet local resource demands in a cost-effective and sustainable way [29]. The resilience.io platform provides the following three modules in series: sociodemographic model to forecast population and business development, agent-based model to simulate spatiotemporal activities and generate resource demands, and resource-technology-network optimisation to find a matrix of technologies with correct location and size, to meet all the demands [3]. The final goal is to plan investment and operational strategies based on economics metrics (e.g.…”

“…Example pathways for processing and use of waste and WtE pathways [3,48]. WtE development that can be achieved in 2036.…”

“…Previous works by Triantafyllidis et al, Wang et al and Bieber et al have demonstrated the use of an integrated platform, resilience.io, to deliver sustainable urban planning and inform decision making [3,29,30]. The platform is integrated with three sub-modules which are social-demographic forecasting model, agent-based model (ABM) and resource technology network (RTN) optimisation.…”

“…Prior researchers have proved the effectiveness of this holistic methodology and platform in supporting resilient decision-making in the context of developing country. The modelling of urban energy system (UES), energy-water-food (EWF) nexus and waste-to-energy system by using resilient.io platform has been conducted and the Greater Accra Metropolitan Area (GAMA) of Ghana is used as the region of case study [3,[29][30][31][32]. The results of these studies provide Ghana with various insights in the field of water supply, energy deployment and waste treatment.…”

“…Biosolid, municipal solid waste, agricultural waste and other organic waste within the study area are considered as (co-)feedstocks of renewable energy generation. Their spatial distribution lays the foundation of quantifying energy potential to be recovered from several WtE pathways[3]. A total of 19 combinations of technologies and feedstocks, including biochemical and thermochemical technologies (anaerobic digestion with thermal options and gasification) are modelled in the resource-technology network of resilience.io.…”