## 2 Construction Aspects for Energy Performance Improvement
### Location and Orientation
#### 2.1.2 Influence of Solar Radiation on Greenhouses
The use of linear Fresnel lenses in a greenhouse as a concentrated photovoltaic system allows direct solar radiation to be retained while diffuse radiation passes through and enters the greenhouse's growing system, improving energy efficiency and reducing the need for cooling in the summer [58]. The study by [PERSON] et al. [59] introduces a photovoltaic/thermal concentrator (CPV/T) system with a cylindrical Fresnel lens in a Chinese solar greenhouse. The system uses a Fresnel lens to concentrate light without blockingactive radiation into the photosynthesis needed by plants. This demonstrates that the system can significantly improve the utilization rate of non-planting space and increase the comprehensive utilization efficiency of the solar power system without negatively affecting plant growth areas. [PERSON] et al. [60] have developed a solar heating system for greenhouses, which operates with a Fresnel lens concentrator and underground heat storage. This system provides continuous heating to the greenhouse during periods without sunshine, promoting a safe environment for plant growth. The research details the construction and functionality of the system, showing through experiments that by burying the heating pipe at a depth of 1.65 m, heat dissipation in the soil occurs in about 5 days, increasing the soil temperature by approximately 4 \({}^{\circ}\)C. This mechanism ensures that the temperature inside the greenhouse remains above 8 \({}^{\circ}\)C, even under adverse weather conditions, without the need for additional energy sources, thus meeting the essential temperature requirements for crop development. The integration of Fresnel lenses into greenhouses can face several limitations, including challenges in uniform light distribution, which can affect plant growth due to the specific design of lenses that focus light on concentrated areas. In addition, aspects such as high installation and maintenance costs, the need for specialized technical knowledge, environmental concerns regarding the life cycle of the materials used, and the susceptibility to external physical conditions such as obstructions and climatic variations, can compromise the efficiency and viability of such systems. However, technological advances and innovative design solutions can help overcome these limitations, enhancing the use of Fresnel lenses for sunlight optimization in agricultural applications [59; 61; 62; 63]. Solar radiation, when effectively managed, can significantly improve crop production and greenhouse energy efficiency [44]. The theme of solar radiation in greenhouses is widely studied by researchers from various areas, such as Agricultural Engineering, Physics, Chemistry and Biology. In addition to the works already referenced, we can also highlight the contributions of ([PERSON] et al. [64]) who reviewed the opportunities for implementing solar energy technologies in agricultural greenhouses, including the integration of photovoltaic and thermal collectors. The study describes that the use of thermal energy storage (TES) systems can increase the overall thermal performance of solar greenhouses by 29%. They emphasized the need for continuous improvements in technology, as well as the importance of TES units in making solar greenhouses a sustainable solution. [PERSON] et al. [65] discussed the challenges of greenhouse design in hot and arid environments, considering cooling strategies and sustainable technologies. They examined important design features of the greenhouses, such as dimensions, orientation, shapes, roofing materials, and shading, as well as effective cooling methodologies and operational strategies for maintaining suitable climatic conditions. In this article, they also highlighted the use of sustainable technologies and clean energy applications to minimize dependence on fossil fuels and promote efficient water management. [PERSON] et al. [66] analyzed the performance of solar greenhouses in different climates, highlighting the importance of choosing roofing materials and proper ventilation.