The authors frame greenhouse operation as a Controlled Environment Agriculture (CEA) challenge involving multiple interdependent targets: air temperature and humidity, CO₂ enrichment, photoperiod-constrained lighting, and irrigation under dynamic and limited energy availability. We propose a knowledge-driven, multi-objective Model Predictive Controller whose cost function integrates expert priorities elicited via an online Analytic Hierarchy Process (AHP) survey; these AHP-derived weights parameterize the controller’s objectives and are solved over two 72 h seasonal episodes, so the MPC can anticipate renewable availability and coordinate HVAC, (de)humidification, CO₂ dosing, LED lighting, and irrigation alongside dispatch from photovoltaic and wind sources, battery storage, and the grid. By embedding the physical interdependence of climate variables directly into the decision layer, the controller schedules energy-intensive actions around renewable peaks and avoids counterproductive actuator conflicts. Seasonal case studies (summer/high solar and winter/low solar) demonstrate robust performance: temperature tracking errors of SMAPE 2.25%/3.05% and CO₂ SMAPE 3.72–3.92%; humidity control with SMAPE 7.04–8.56%; lighting and irrigation following setpoints with low NRMSE (0.08–0.14). Summer energy was 59% renewable; winter was only 13%, increasing grid reliance to 77.5% (peaks: 4.57 kW/6.92 kW for 197.7/181.5 kWh). Under water or energy scarcity, the controller degrades gracefully, protecting high-priority agronomic variables while allowing bounded relaxation on lower-priority targets. This expert-informed, predictive, and resource-aware orchestration offers a scalable route to precision greenhouse control within the food–water–energy nexus.

This systematic review synthesizes passive and passive-first cooling strategies for greenhouses in hot–arid climates, organizing evidence across four domains: Airflow & Ventilation, Shading & Radiative Control, Thermal Storage & Ground Coupling, and Structural Design & Geometry. Drawing on the project corpus, we analyze 10–13 distinct techniques including ridge and side natural ventilation, windcatchers and solar chimneys, external shade nets, NIR-selective and transparent radiative-cooling films, and dynamic PV shading; earth-to-air heat exchangers (EAHE/GAHT), rock-bed sensible storage, phase-change materials (PCMs), and sunken or buried envelopes; as well as roof slope and shape, span number, and orientation. Across studies, cooling outcomes are reported as peak or daytime indoor air temperature reductions, defined relative either to outdoor conditions or to a control greenhouse, with the reference frame and temporal aggregation specified in the synthesis. Typical outcomes include ≈3–7 °C daytime reduction for optimized ventilation, ≈2–4 °C for shading and spectral covers while preserving PAR, ≈5–7 °C intake cooling for EAHE with winter pre-heating, and up to ≈14 °C peak attenuation for rock-bed storage under favorable conditions. Structural choices consistently amplify these effects by sustaining pressure head and limiting thermal heterogeneity. Performance is strongly context-dependent—governed by wind regime, diurnal amplitude, dust and UV exposure, and crop-specific light and temperature thresholds—and the most robust results arise from stacked, site-specific designs that combine skin-level radiative rejection, buoyancy-supportive geometry, and ground or latent buffering with minimal active backup. Smart controllers that modulate vents, shading, and targeted fogging or fans based on VPD or temperature differentials improve stability and reduce water and energy use by engaging actuation only when passive capacity is exceeded. We recommend standardized composite metrics encompassing temperature moderation, humidity stability, PAR availability, and water and energy use per unit yield to enable fair cross-study comparison, multi-season validation, and policy adoption. Collectively, the synthesized techniques provide a practical palette for improved greenhouse climate management under hot and arid conditions.

Freshwater scarcity remains a major challenge across many African regions, particularly in remote and arid areas where access to centralized water infrastructure and reliable energy resources is limited. In this context, humidification–dehumidification (HDH) desalination represents a promising decentralized solution for sustainable freshwater production due to its low operating temperature, simple design, and compatibility with renewable energy systems. However, the efficiency of conventional HDH systems is often constrained by passive condensation processes that are highly sensitive to ambient climatic conditions. This study presents a numerical investigation of an innovative HDH desalination system integrating active thermoelectric condensation using Peltier cooling modules. The proposed system operates in a closed-loop water circulation, open-air configuration and incorporates dual evaporators and a coaxial air–water heat exchanger to improve heat recovery and thermal efficiency. The system is designed to be powered by solar photovoltaic energy, making it suitable for decentralized and off-grid applications in water-stressed regions. A comprehensive numerical model was developed using MATLAB to simulate the system performance under various climatic conditions. Simulation results demonstrate that the active condenser significantly improves freshwater productivity compared to conventional passive configurations. Under hot and dry climatic conditions (38 °C and 45% relative humidity), the system achieved a maximum freshwater production corresponding to a 57% improvement compared to a conventional single-evaporator HDH system and a 22% increase relative to a passive-condenser configuration with heat recovery. In addition, the thermoelectric condenser maintained stable condensation performance under highly humid conditions, ensuring improved operational reliability and resource efficiency. The findings highlight the potential of combining renewable energy, heat recovery, and active thermoelectric cooling to develop sustainable and energy-efficient desalination technologies adapted to African environmental conditions. The proposed system contributes to decentralized water production, environmental sustainability, and the strengthening of climate-resilient water solutions for vulnerable communities.