Recent research studies and policies about innovative solutions to reduce water and energy consumption in food production are briefly reviewed. Options to increase water use efficiency and productivity include soil mulching, drip irrigation, deficit irrigation, and precision agriculture. As for the energy–water nexus, attention is focused on energy audits of water distribution networks; improving of system performance –– network sectoring, use of variable speed drives, critical points control, electricity tariff — and reduction of wastewater treatment’s energy use. At a larger scale, other solutions emerge: diversification and rotation of crops, cultivation of drought-resistant crops, and optimization process of the spatial distribution of cropping patterns. The rebound effect that can be associated to these options is also considered.

This study explores the potential effects of electricity pricing on crop cultivation in Saudi Arabia. The country recently started implementing a domestic energy price reform strategy to make energy consumption more sustainable and increase government revenues as highlighted in the Fiscal Balance Program one of the key realization programs of Vision 2030. Two modeling schemes were developed to complete this analysis. First, a model that applies physical equations to estimate water and energy requirements for 21 crops across 13 provinces. Second, an optimization model that runs iteratively to determine short-run electricity costs, import costs and export revenues. The main finding from the model simulations is that increasing electricity prices will shrink the domestic cultivation and exports of the crops while increasing their imports. For example, as an extreme case, if the agriculture electricity price is raised from $0.048 per kWh to the US industrial electricity price level of $0.692 per kWh, the model optimizes that this will reduce electricity consumption from 33.65 gWh to 7.84 gWh, domestic crop cultivation from 15.1 million tons to 6.3 million tons, and crops' export from 0.062 million tons to 0.057 million tons while will increase crops’ import from 9.5 million tons to 18.3 million tons.

Sustainable use and management of nutrients is an important issue for food, energy and water systems. The close connections between the three systems, reflected by the “nexus” concept, warrant an integrated approach to nutrients management across the nexus. In this paper, dynamic modelling of nutrient flows in a local food-energy-water system is presented and applied to a simplified case study. The model was used to simulate several scenarios affecting nitrogen flows and stocks to assess the impact of a) the level of local wheat production, b) the selection of energy generation technology, and c) the management of available nutrient resources (digestate and straws). The simulation results showed that varying the proportion of locally produced wheat significantly affects the surface runoff and the nitrogen content in a local water body, with the latter increasing by nearly 70% in 50 years if about half of the wheat consumed is produced locally as opposed to being 100% imported. The introduction of anaerobic digestion as an energy generation option helps to supply more electricity, reduce the imported fertiliser, and also significantly reduce the landfilled nitrogen nutrient by up to 60 times, due to the reuse of the anaerobic digestate. On the other hand, a balanced consideration should be given between using the straw as fertiliser and as feedstock for energy generation. This work offers a first analysis of the food-energy-water nexus with a focus on nutrient flows and stocks. The modelling approach has the potential to inform holistic decision making with respect to nutrient usage, efficiency and the related environmental impact in the design of a local system for meeting the demand for food, energy and water.

Water, energy, and agriculture have been conventionally dealt with separately in investment planning. For each of these sectors, regulatory frameworks, organizations, and infrastructures have been put in place to address sector-specific challenges and demands. As the Middle East and North Africa works towards building a more sustainable future, a nexus approach that considers the risks and synergies among these sectors is needed. To demonstrate the added value of a nexus approach, this report applies scenario analysis and integrated assessment modelling of the water-energy-food nexus to the Middle East and North Africa. The analysis finds that water scarcity increases in all countries in the region over the coming decades, mostly due to growing demands. More importantly, the analysis finds that many countries in the region could run out of fossil groundwater by 2050 unless measures to curb unsustainable abstraction are implemented. The impacts of growing scarcity on agriculture are significant, with production projected to drop by 60 by 2050 in some countries. On the upside, reducing the dependence of the agricultural and energy sectors on water and transitioning to renewable energies can reduce water scarcity, at the same time reducing greenhouse gas emissions. This report is targeted to policy makers, the academic community, and a wider global audience interested in exploring the interactions between water, agriculture, and energy.

The water-energy-food (WEF) nexus concept highlights the importance of integrative solutions that secure resource supplies and meet demands sustainably. There is a need for translating the nexus concept into clear frameworks and tools that can be applied to decision making. A simulation and analytics framework, and a concomitant Nexus Simulation System (NexSym) is presented here. NexSym advances the state-of-the-art in nexus tools by explicit dynamic modelling of local techno-ecological interactions relevant to WEF operations. The modular tool integrates models for ecosystems, WEF production and consumption components and allows the user to build, simulate and analyse a “flowsheet” of a local system. This enables elucidation of critical interactions and gaining knowledge and understanding that supports innovative solutions by balancing resource supply and demand and increasing synergies between components, while maintaining ecosystems. NexSym allowed assessment of the synergistic design of a local nexus system in a UK eco-town. The design improved local nutrient balance and meets 100% of electricity demand, while achieving higher carbon capture and biomass provisioning, higher water reuse and food production, however with a remarkable impact on land use.

Water, energy and food (WEF) are inextricably interrelated. Effective planning and management of limited WEF resources to meet current and future socioeconomic demands for sustainable development is challenging. WEF production/delivery may also produce environmental impacts; as a result, green-house-gas emission control will impact WEF nexus management as well. Nexus management for WEF security necessitates integrated tools for predictive analysis that are capable of identifying the tradeoffs among various sectors, generating cost-effective planning and management strategies and policies. To address these needs, we have developed an integrated model analysis framework and tool called WEFO. WEFO provides a multi-period socioeconomic model for predicting how to satisfy WEF demands based on model inputs representing productions costs, socioeconomic demands, and environmental controls. WEFO is applied to quantitatively analyze the interrelationships and trade-offs among system components including energy supply, electricity generation, water supply-demand, food production as well as mitigation of environmental impacts. WEFO is demonstrated to solve a hypothetical nexus management problem consistent with real-world management scenarios. Model parameters are analyzed using global sensitivity analysis and their effects on total system cost are quantified. The obtained results demonstrate how these types of analyses can be helpful for decision-makers and stakeholders to make cost-effective decisions for optimal WEF management.

Using water-energy-food-environment (WEFE) nexus as the prism, this review explores evolution of groundwater governance in Iran, Saudi Arabia, Mexico, China, Bangladesh and India – which together account for two-thirds of the global groundwater-irrigated area. Global discourse has blamed widespread water scarcity squarely on supply-side policymaking and advocated a broader template of water governance instruments. Integrated Water Resources Management (IWRM) presented just such a template – with pricing, participation, rights and entitlements, laws, regulations, and river basin organizations – as additional water governance tools. However, the IWRM template faced disillusionment and pushback in many emerging economies. WEFE nexus, the new paradigm, prioritizes system-level optima over sectoral maxima by harnessing synergies and optimizing trade-offs between food, water, energy, soil, and eco-system sustainability within planetary boundaries. Realizing this vision presents a complex challenge in groundwater governance. Global groundwater economy comprises three sub-economies: (a) diesel-powered unregulated, as in Nepal terai, eastern India, Bangladesh, Pakistan Punjab and Sind, and much of Sub-Saharan Africa, where use-specific energy subsidies are impractical; (b) electricity-powered regulated, as in North America and Europe, where tubewells are authorized, metered and subject to consumption-linked energy charges; and (c) electricity-powered unregulated, as in geographies covered by our review – barring China, Bengal and Bangladesh – where unmeasured electricity subsidies have created a bloated groundwater economy. This last sub-economy represents the heartland of global groundwater malgovernance, least equipped to meet the sustainability challenge. It has an estimated 300 million horsepower of grid-connected electric pumps that are either unauthorized and/or unmetered and/or use free or heavily subsidized or pilfered power for irrigating 50–52 million hectares, nearly half of global groundwater-irrigated area. In (a) and (b), groundwater scarcity inspires water-energy saving behavior via increased energy cost of pumping. In sub-economy (c), users are immune to energy costs and impervious to groundwater depletion. Here, the WEFE nexus has remained blind to the irrigation realpolitik that catalyzes or constrains policy action. We explore why the political costs of rationalizing subsidies are prohibitive and exemplify how a smart transition from fossil to solar energy for pumping may offer an opportunity to turn the perverse WEFE nexus into a virtuous one.

The sufficient supply of food and energy requires large amounts of fresh water. Mainly required for irrigation, but also processing and cooling purposes, water is one of the essential resources in both sectors. Rising global population numbers and economic development could likely cause an increase in natural resource demand over the coming decades, while at the same time climate change might lead to lower overall water availability. The result could be an increased competition for water resources mainly in water-stressed regions of the world in the future. In this study we explore a set of possible changes in consumption patterns in the agricultural and energy sector that could be primarily motivated by other goals than water conservation measures—for example personal health and climate change mitigation targets, and estimate the indirect effect such trends would have on global water requirements until 2050. Looking at five world regions, we investigated three possible changes regarding future food preferences, and two possible changes in future resource preferences for electricity and transport fuels. We find that while an increase in food supply as a result of higher protein demand would lead to an increase in water demand as well, this trend could be counteracted by other potential dietary shifts such as a reduction in grains and sugars. In the energy sector we find that an increasing water demand can be limited through specific resource and technology choices, while a significant growth of first-generation biofuels would lead to a drastic rise in water demand, potentially exceeding the water requirements for food supply. Looking at the two sectors together, we conclude that an overall increase in water demand for both food and energy is not inevitable and that changes in food and energy preferences could indeed lead to an alleviation of water resource use despite rising population numbers.

PURPOSE: The food processing industry is a major consumer of energy and water, the consumption of which has environmental impacts. This work develops a method to determine process-specific water use and utilizes an existing energy use toolbox to calculate the energy and water required for each step of food processing. A life cycle assessment (LCA) is conducted to determine how much processing contributes to a particular product’s cradle to gate impacts for two impact categories. METHODS: A method to determine water use at each unit process was developed, and in conjunction with an already developed energy use unit process toolbox, the methods were tested using two case studies. Processing data such as flow rates, operation temperatures, and food losses were used from two Swiss food production facilities. Calculation results were compared to measured facility data such as yearly energy and water use. Results were then used to develop LCAs for a total of seven food products, including five types of juice and two types of potato products. RESULTS AND DISCUSSION: The toolboxes were able to calculate the water use of both facilities within 25%, the thermal energy use within 9%, and electricity use within 24%. Impacts from processing were particularly important for the potato products, particularly potato flakes, due to impacts stemming from thermal energy use. For juices, impacts due to raw material growth dominate the LCA, and impacts due to processing are much less significant. A unit process analysis may not be necessary when there is little variation in the unit processes between the different products. In this case, a simple allocation of measured facility energy and water data may be sufficient for calculating the impacts associated with processing. However, products with largely varying unit processes may have very different impacts. Impacts are sensitive to the type of energy required (thermal or electrical) and the sources of electricity and water. CONCLUSIONS: These water and energy toolboxes can improve transparency in processing and identify the most water- and energy-intensive steps; however, in facilities with similar products, such an extensive analysis may not be necessary. Results from these calculations are useful in developing food product LCAs.

The safety of the water–energy–food (WEF) system in the China–Pakistan Economic Corridor (CPEC) is critical to the sustainable development of resources, the economy, and society in the region. This paper uses the projection pursuit model of a real-code accelerated genetic algorithm (RAGA-PP) to comprehensively evaluate the WEF system security of the CPEC for the period 2000–2016. The results show that from 2000 to 2016, the projection value of the WEF system was reduced from 2.61 to 0.53, and the overall system security showed a downward trend. Moreover, the CPEC increased by 6.13 × 10⁷ people, resulting in a rapid decrease in per capita water resources and decreased security of the water resources subsystem. With the rising social and economic development in recent years, the per capita energy consumption has likewise risen, leading to a decline in the energy subsystem. At the same time, the per capita grain output in the study area has increased from 185 to 205 kg, and the safety of the food subsystem has been enhanced. However, the significant increase in irrigated areas (from 1.82 × 10¹⁰ to 1.93 × 10¹⁰ hectares) has further highlighted the contradiction between the supply and demand of surface water resources, and the number of tube wells increased by 7.23 × 10⁵, resulting in the consumption of a large amount of electricity and diesel resources. The water–energy (WE) subsystem also became less safe. With the implementation of water resources management policies over the past few decades, the proportion of agricultural water consumption dropped from 95.06% in 2000 to 93.97% in 2016, and the safety of the water–food (WF) subsystem increased. Unfortunately, agricultural irrigation consumes a large amount of power resources, leading to a reduction in the security of the energy–food (EF) subsystem. The research results from the present study could provide a scientific basis for the coordinated development of WEF systems across the CPEC region.