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•Dynamic photovoltaic (PV) greenhouses with various PV densities are modeled.•Energy performance under different sun-tracking methods is analyzed.•No-shading sun tracking improves the ...performance of high-density PV greenhouses.•Mixed sun-tracking schemes can balance the production of food and electricity.
Dynamic photovoltaic (PV) greenhouses integrate sustainable energy generation with plant cultivation, offering more possibilities of energy production and microclimate control by adjusting the sun-tracking angles. Previous studies on PV greenhouses barely paid attention to the PV partial shading effects, and rarely recorded the performance across the full range of rotation angles. In this study, we first build computer simulation models of typical greenhouses with high-density (1/2 roof area) and low-density (1/3 and 1/4 roof area) PV layouts. Then four special sun-tracking positions are found in the model of equivalent global irradiance, which is defined as the quotient of the total input power divided by the area of PV module under partial diffuse shadows. Simulation models are also built in terms of PV modules and interior irradiance. Simulations are conducted using the climate data of Delft, the Netherlands (52.01°N,4.36°E). Results show that high-density PVs under no-shading sun tracking generate 6.91% more energy than that under conventional (quasi-perpendicular) sun-tracking. Meanwhile, no-shading sun tracking allows more diffuse sunlight to enter the greenhouse mounted with high-density PV panels, resulting in 10.96% and 10.68% improvement on the annual average global irradiance and uniformity on the target plane compared to the fixed PV panels in the closed position. Regarding low-density PV layouts, which barely suffer from partial shading problems, quasi-perpendicular sun tracking improves the annual energy generation by 7.40% relative to the closed position. However, the average global irradiance reaches the minimum in this position because more sunlight is blocked by PVs. Meanwhile, the average uniformity of global irradiance reveals good (but not the best) performance, resulting in up to 9.80% (1/3 coverage) and 4.70% (1/4 coverage) improvement respectively compared to the closed position. The proposed methods and simulation results provide guidelines for the initial design and daily operation of PV greenhouses, aiming to balance the PV power generation and food production.
Green roofs are an increasingly important component of water-sensitive urban design systems that can potentially improve the quality of urban runoff, reduce the energy consumption of buildings, and ...add esthetic value to the environment. The most important green roof abilities, which appear as a key feature in urban catchments are the ability of rainwater detention and retention and reduction in energy consumption. This paper aims to provide an overview of the effects of the application of the green roof strategy on the quality of runoff water and the reduction of energy consumption. The components of a green roof are discussed, and the advantages and disadvantages of different types of green roofs are assessed. In addition, the origins and concentrations of the main pollutants are discussed, moreover environmental cost-benefits of green roofs are also considered. In addition, the main factors that affect the quality of green roof runoff water, e.g., plant species, fertilization, pH, growth media as well as how green roofs could reduce energy consumption are discussed. Green roofs are considered as sustainable approach for runoff management with achieved aesthetical values and in combination with energy saving on heating/cooling. Hence, green roof causes a sufficient decrease in energy consumption and consequently in the related energy costs. It can help to improve the micro climate around the buildings and save money and also improve water quality. Therefore, green roofs may turn into a profitable investment. Some recommendations for future study also are proposed.
Mikroklima je specifična klima nekoga manjega, a često ograničenoga prostora, šume, livade, nekih reljefnih oblika itd. Ona ovisi o makroklimi širega prostora, ali i o drugim stanišnim i sastojinskim ...čimbenicima. Cilj je istraživanja bio analizirati mikroklimu vrtače ili ponikve, krškoga fenomena. Istraživanje je obavljeno na području Cipala u Nacionalnom parku Sjeverni Velebit. Mikroklima je izmjerena na tri različite pozicije vrtače, a to su obod (rub), sredina i dno vrtače. Izmjereni su klimatski elementi temperatura zraka (°C), relativna vlažnost zraka (%), temperatura tla (°C) i volumetrijska vlaga tla (%). Najveća je amplituda temperature zraka bila na obodu vrtače. Temperatura se zraka smanjivala s dubinom vrtače, a relativna se vlaga zraka povećavala s dubinom vrtače. Za oba je klimatska elementa postojala statistički značajna razlika samo na dnu vrtače. Temperaturni gradijent u vrtači je iznosio 0,7 °C. Temperatura se tla značajno smanjivala od oboda vrtače do dna vrtače. Apsolutna minimalna vrijednost vlage tla bila je na obodu vrtače, a apsolutna maksimalna vlaga tla bila je na sredini vrtače, gdje je utvrđena i najveće kolebanje vlage tla. Volumetrijska se vlaga tla statistički značajno razlikovala na sva tri mjesta u vrtači. Mikroklima vrtače utjecala je na obrnuti raspored šumskih ekosustava s obzirom na nadmorsku visinu.
Microclimate is the specific climate of a smaller, often limited space, forest, meadow, some landforms, etc. It depends on the macroclimate of the wider area, but also on a number of other habitat and stand factors. The aim of the research was to analyse the microclimate of one of the karst phenomena – a sinkhole. The research was carried out in the area of Mule in the Northern Velebit National Park. The microclimate was measured at three different positions of the sinkhole, namely the rim, middle and bottom of the sinkhole. The following climatic elements were measured: air temperature (°C), relative air humidity (%), soil temperature (°C) and volumetric soil moisture (%). The highest air temperature amplitude was observed at the rim of the sinkhole. The air temperature decreased with the depth of the sinkhole, and the relative air humidity increased with the depth of the sinkhole. For both climatic elements, there was a statistically significant difference only at the bottom of the sinkhole. The temperature gradient in the sinkhole was 0.7 °C. Soil temperatures decreased significantly from the rim to the bottom of the sinkhole. The absolute minimum value of soil moisture was observed at the rim of the sinkhole, and the absolute maximum soil moisture in the middle of the sinkhole, where the greatest fluctuation of soil moisture was found. Volumetric soil moisture was statistically significantly different at all three positions in the sinkhole. The microclimate of the sinkhole affected the inverse arrangement of forest ecosystems with respect to altitude.
In urban areas the impact of built environment on wellbeing and human health should be considered due to urban heat island phenomenon. The present research aims at identifying a method for an ...accurate estimation of thermal outdoor comfort and mean radiant temperature, modeling and simulating the effects of urban form and vegetation on microclimate of cities. In order to reach this main objective, this research incorporates CFD based simulation tool ENVI-met and TRNSYS (Transient Systems Simulation) by means of Grasshopper. The results of the study demonstrate the reliability of the proposed method, i.e. that a combination of ENVI-met and TRNSYS increases the simulation accuracy in terms of outdoor thermal comfort, especially during night. This method allows exploiting the potentialities of both ENVI-met and TRNSYS for the calculation of urban features (urban form, vegetation, canyon proportion, etc.) affecting urban microclimate.
•The inclusion of urban ventilation for performance-based planning.•Relationships between urban ventilation and urban topology at different urban scales were summarized.•A framework for precinct ...ventilation performance was developed.•We defined the protocol for precinct ventilation zone based on building height, street structure and compactness.•20 precinct ventilation zones were classified in the context of Greater Sydney of Australia.
Along with ongoing urban development, cities are experiencing significantly different climates compared with surrounding rural or suburban areas. Among various causes, the traditional modification towards urban surface structures has been evidenced as an explanation for the variations of urban climate. This affirms the significances of urban morphology in urban climate study and management. However, urban morphology that focuses on the homogeneity of urban form is always very intricated, so that it is essential to clearly describe and differentiate the interactions between urban morphology and climatic conditions. Focusing on guiding ventilation performance-based planning, therefore, this paper aims at characterizing urban surface structures for the systematic studies of local ventilation performance. In specific, based on the pluridisciplinary method, this paper developed the protocol for the precinct ventilation characterization. The precinct ventilation zone system was derived according to ‘compactness + building height + street structure’, based on which 20 distinctive types of precinct ventilation zones in the Greater Sydney, Australia were presented. The classification system in this paper can provide wind-related researchers, engineers, designers and planners with intuitive understandings of the ventilation performance, thereby further assisting decision makers to formulate sound planning regulations with the inclusion of urban ventilation.
•Field measurements of urban microclimate and trees were conducted.•Cooling effects of shading and transpiration of urban trees were simulated separately.•Four scenarios of tree conditions were ...developed to demonstrate building energy load differences.•Scientific-based suggestions for urban afforestation were proposed.
Building cooling energy use is regarded as the hot topic of building research due to its increasing trend at a rate proportional to the total direct energy use in urban areas nowadays. Urban greening as an effective countermeasure in reducing building cooling load has been attracting close attention although there is a shortage of quantitative measures for applying the general idea to a specific site or building. This study addresses this problem. The cooling effect of trees around buildings and the influence of tree characteristics on building cooling load reduction was quantified using microclimate field measurements and sap flow rate of trees. By integrating approaches of field measurements of microclimate and tree characteristics into EnergyPlus simulation of building energy use, the cooling effects of trees due to both shading and transpiration on buildings were quantified and discussed. Four scenarios were developed based on different tree characteristics for quantifying the influence of trees on saving of building energy use: Scenario 1 with treeless condition, Scenario 2 with existing trees condition in a case of Nanjing City, Scenario 3 with more tree shading condition, and Scenario 4 with more tree transpiration condition. The simulation results showed that compared to Scenario 1, Scenario 2 can reduce building energy use by 10.3% due to the benefits from existing trees shading and transpiration. More shading in Scenario 3 and a higher transpiration rate in Scenario 4 can reduce building energy use by 15.2% and 12.4%, respectively in comparison to that in Scenario 1.
Abstract
This research attempts to explore the aesthetic inputs of the Baghdadi House, which for many years has become a symbol of Iraqi architecture and its shape has evolved as a result of the ...skill of Iraqi sculptors and architects in the use of wood and bricks and the adaptation of these materials to give a special aesthetic to the Baghdadi House made it aesthetically sustainable. The problem of the research was the existence of a knowledge gap about the factors that contributed to enrich the details of the Baghdadi House to give it the required aesthetic sustainability. Therefore, the research adopted hypothesis (that the aesthetic of Baghdadi House results from the interaction of sustainability factors and local materials that enrich the details of the house among them in addition to that experience The Iraqi architecture added another aesthetic dimension to him) the research adopted the descriptive approach on the concept of beauty and the application of beauty levels on the elements of the Baghdadi House as well as adopted the analytical approach through the effective indicators on four different samples of houses The aim of the research is to know the aesthetic sustainability of the house by using local materials in the implementation of the Baghdadi. the results of research there is aesthetic sustainability through two indicators are architectural aesthetic and micro climate has given Interaction of the central courtyard with parts of the Baghdadi house
The regenerative approach to design goes beyond limiting the environmental impact of the built environment and towards the enrichment of the ecosystem, adaptation to climate change, and the ...improvement of human health. This concept is being applied to buildings through new standards such as the Living Building Challenge, yet examples of implementation of regenerative design at the urban scale are rare. While this is a promising direction for sustainable design, in theory new metrics, design tools and workflows need to be developed to translate regenerative design concepts into practice effectively. Among other factors, barriers to implementation remain rooted in the shortcomings of existing urban simulation tools to evaluate a wide range of performance metrics simultaneously. This paper thus proposes a prototype workflow to evaluate regenerative performance using existing evaluation tools in a single digital workflow. A series of existing and customised plugins, most of which are already in use and open source, were integrated into a multi-parametric workflow based on the Grasshopper visual programming tool. The workflow was tested on Malaga as a case study and incorporated key performance indicators related to outdoor human thermal comfort, biophilia, daylight performance, and energy use and production, based on data exchange and synergies across the different tools. These indicators were evaluated for present and future climate scenarios obtained from a weather generator. This paper demonstrates the potential of this workflow to receive visual feedback on various aspects of regenerative urban design, thus enabling designers to more effectively pursue an evidence-based urban design process.
•Key Performance Indicators for Regenerative Design defined for an urban context.•Multi-layered parametric workflow based on data exchange defined in Grasshopper.•Importance of connecting algorithms to evaluate performance highlighted.•Modelling of future climates, urban energy, and environmental quality discussed.•Findings may improve adoption of evidence-based urban design.
People living in cities are experiencing summerly heat stress situations with severe consequences for their health, especially under climate change. Urban planning needs to address this problem ...focusing on areas where people are exposed to heat such as in public squares. Typical square designs include green infrastructure which can positively affect outdoor thermal comfort by providing regulating ecosystem services, but knowledge on the effectiveness of different design approaches is still limited. The present study assessed typical greening designs of rectangular public squares and their microclimatic influences during a hot summer day both during day and night-time conditions. By using a validated ENVI-met V4 model, thermal comfort values expressed by the physiologically equivalent temperature (PET) index were compared. Moreover, a novel greening design was developed and tested with the model. The results showed that at 3pm the greening design with most trees and trees placed in the sunlit areas of the square provided 5.2% higher cooling effect compared to the current greening, whereas for 4am the design without trees, but with meadow areas performed best (4.2% heat reduction). This led to the conclusion that for a comfortable thermal situation a climate adapted design has to include trees to maximize the shaded surface areas, while the main wind channel is kept free from trees, but planted with grass to minimize the heat storage. The number of trees and their placement together with the extent and placement of grass areas can thus serve as indicators for designing climate adapted public squares.
•The summerly cooling potential of public squares depends on their greening design.•Typical and novel designs for public open spaces were tested with ENVI-met.•At daytime designs with a maximum shaded area provide best thermal conditions.•At night unhindered air flow and reduced heat storage in meadows performed best.•Trade-offs between them need to be considered for designing climate adapted cities.
Defining the rate of air emissions fee Ivanova, M P; Tagaeva, T O
IOP conference series. Earth and environmental science,
01/2021, Letnik:
629, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Industrial production disturbs the balance of an already delicate environment, and there is a negative impact on the microclimate in the area that is imposed due to cross-regional pollution. The ...essence of the problem is the movement of hazardous air pollutants throughout the atmosphere over the long distances, and the issue of government control over the air emissions acquires cross-regional significance. Additionally, particular attention should be paid to the question of payment for air emissions. Today, the economic instruments to reduce the negative environmental impact and to ensure compliance with the environmental regulations are only partially applied. All mentioned above underline the need for consideration of the given problem, which can be solved by the additinal method. Therefore, the authors of the present paper suggest a method to define the rate of air emissions fee (currently there are no rates applied). Besides, it should be stressed that this method would allow for effective calculation of payments for harmful pollutant discharge into air. The research outcomes can be used to further develop environmental regulations.
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