A comprehensive review of solar‐driven desalination technologies for off‐grid greenhouses

Summary This paper is motivated by the crisis of freshwater in remote areas around the world and responds to the growing need for sustainable food production in arid lands. It focuses on utilizing solar energy to yield freshwater from the sea or brackish water with less environmental impacts, for greenhouses, which can produce sustainable food all over the year. The integration of various solar‐driven desalinations such as solar still, humidification‐dehumidification, reverse osmosis, electrodialysis, and multieffect and multistage flash with greenhouses are evaluated, for better sustainability towards greenization. The paper first discusses the specifications of solar‐driven desalinations and compares their advantages and limitations. Then, different types of greenhouses are introduced, and their total water requirement is discussed based on their locations, crop type, greenhouse technology, irrigation type, and environmental conditions, as well as their cooling and heating strategies. Later, the existing integration of solar‐driven desalinations with greenhouses are reviewed, and their advantages and limitations are deliberated. Finally, the paper discusses the criteria to be considered when selecting solar‐driven desalinations for greenhouses and presents a detailed comparison between the water production rate and cost as well as the energy consumption of these systems. In the end, the most appropriate combinations of solar‐driven desalinations with greenhouses are recommended based on their water requirement and production cost. This paper has focused on off‐grid greenhouses, supplied with solar‐driven desalinations. Direct and electrolysis solar‐driven desalinations are found more suitable for small‐scale greenhouses while solar thermal reverse osmosis, multieffect distillation, and multistage flash are more appropriate for medium and large‐scale applications. From energy consumption and water production cost perspective, solar photovoltaic‐powered reverse osmosis and electrodialysis desalinations are recommended for small‐scale greenhouses, while solar thermal reverse osmosis and multieffect distillation are better for medium‐ and large‐scale greenhouses.