The increasing demand for food, the lack of natural resources and arable land, and the recent restrictions on energy consumption require an immediate solution in terms of agricultural activities. This paper’s objective was to review hydroponics (a new soilless cultivation technology) and compare it with conventional agriculture (soil cultivation) regarding its environmental impact and water and energy consumption. The soil loss, the crop/soil contamination, and the greenhouse gas emissions were the criteria for the environmental comparison of conventional agriculture and hydroponics. As for resource consumption, the water consumption rates (L/kg), energy consumption rates (kWh), and energy required (kW) were the criteria for comparing conventional agriculture with hydroponics. Tomato and cannabis cultivation were used as case studies in this review. The review results showed that the advantages of hydroponics over conventional cultivation include zero-soil cultivation, land-use efficiency, planting environment cleanliness, fertilizer and resource saving, water consumption reduction, and conservation. The disadvantages of hydroponics versus conventional cultivation were found to include the high investment costs, technical know-how requirements, and higher amount of demanded energy.

This study calculates the intensity of radiation received by two types of greenhouses: Even Span and Modified Arched geometry. The Even Span greenhouse is covered with glass, while the Modified Arched greenhouse is covered with polyethylene plastic sheets. Both greenhouses are located in the same geographical area. The analysis incorporates various forms of radiation, including incident, reflected, transmitted, and absorbed radiation, calculated based on solar angles. Notably, this study does not include temperature data. The greenhouse covering material is considered transparent, and parameters such as the refractive index and the attenuation coefficient of the materials are integrated into the calculations. The integration of these specific indices allows for the calculation of radiation across different materials. Additionally, this study assesses radiation for all sides of the greenhouse, rather than focusing solely on the roof. The research analyses data from a total of 396 days, with measurements taken every ten minutes from a meteorological station situated near the greenhouses. MATLAB (R2021b) software is utilised for computational purposes to solve the relevant equations, while IBM SPSS Statistics 28.0.0.0 software is employed for statistical analysis of the results. The statistical analysis regards data collected from sunrise to sunset, varying by month. It is important to note that radiation values recorded with a negative sign are retained in this analysis, as they are considered useful for capturing the temporal and spatial dynamics of radiation within the model. The analysed greenhouses are geographically situated in the Psachna area of Messapia, Evia Prefecture, Greece.