7.2 Nexus sound solutions - Overview
The smart combination of single-sector technologies allows to tap the synergies within the water, energy, and food nexus.
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Nexus smart solutions include agrivoltaics, water and electricity cogeneration systems, solar-powered irrigation systems (see examples), saline water greenhouses (Al-Ismaili and Jayasuriya, 2016), water efficient cooling towers (Pan et al. 2018), recycling of solid waste and wastewater for energy supply (Wang et al., 2017) and fertilization (González-Sierra et al., 2019), and phosphorous and nitrogen recovery (Chrispim et al. 2019, Robles et al. 2020).
7.2.1 Water-Energy-Food Nexus Sound Solutions (WEF-NSS)
All kind of solutions which address WEF nexus challenge and increase resource use efficiency across sectors by tapping synergies and/or minimizing trade-offs. WEF NSS include technology-based systems, nature-based systems, hybrid systems. The systems can encompass multiple sectors or act only in a single sector while indirectly affecting other sectors (e.g., smart irrigation system).
Further, WEF NSS comprise policies, cross-sector coordination instruments, and integrated resource management strategies. The cross-sector efficiency gains can occur at all points of the system processes (source, transformation/conversion, storage, end-use) or can also be induced through the solution (policy, the establishment of cross-sector coordination, integrated resource management).
7.2.2 WEF Polyservice Systems
WEF polyservice system refers to cross-sector technology-, nature-based, and hybrid systems addressing WEF nexus challenges. They interlink at least two sectors and tap direct and indirect synergistic effects across sectors.
7.2.3 WEF Polygeneration/Polyproduction Systems
The term is inspired by the energy sector (e.g., heat and power cogeneration) and expresses the system’s variety of provided end-uses. The term “polygeneration” indicates that the system produces at least two commodities for end-use in different sectors (e.g., Agrophotovoltaics: Electricity and Crops).
7.2.4 Examples and categories of nexus integrated solutions
References
Al-Ismaili, A. M., & Jayasuriya, H. (2016). Seawater greenhouse in Oman: A sustainable technique for freshwater conservation and production. Renewable and Sustainable Energy Reviews, 54, 653–664, https://doi.org/10.1016/j.rser.2015.10.016
Chrispim, M. C., Scholz, M., & Nolasco, M. A. (2019). Phosphorus recovery from municipal wastewater treatment: Critical review of challenges and opportunities for developing countries. Journal of Environmental Management, 248, 109268, https://doi.org/10.1016/j.jenvman.2019.109268)
González-Sierra, R. P., Arrizmediarrieta, J. S., Sánchez, B. P., Iriate, I. I., & Duarte, G. N. (2019). Community Composting: A Practical Guide for Local Management of BIowaste.
Pan, S.‑Y., Snyder, S. W., Packman, A. I., Lin, Y. J., & Chiang, P.‑C. (2018). Cooling water use in thermoelectric power generation and its associated challenges for addressing water-energy nexus. Water-Energy Nexus, 1(1), 26–41, https://doi.org/10.1016/j.wen.2018.04.002
Robles, Á., Aguado, D., Barat, R., Borrás, L., Bouzas, A., Giménez, J. B., . . . Seco, A. (2020). New frontiers from removal to recycling of nitrogen and phosphorus from wastewater in the Circular Economy. Bioresource Technology, 300, 122673, https://doi.org/10.1016/j.biortech.2019.122673
Wang, X., Guo, M., van Dam, K. H., Koppelaar, R. H.E.M., Triantafyllidis, C., & Shah, N. (2017). Waste-Energy-Water systems in sustainable city development using the [resilience.io], Paltform. In Computer Aided Chemical Engineering. 27th European Symposium on Computer Aided Process Engineering (Vol. 40, pp. 2377–2382). Elsevier. https://doi.org/10.1016/B978-0-444-63965-3.50398-6