Sunny Climate Research Articles

Solid combined Sun-protective devises for windows with different orientation aspects in the conditions of hot and Sunny climate

The article deals with the essential problems of Sun-protection by means of newly offered type of solid combined Sun-protective devices (S.P.D.) in the conditions of hot and Sunny climate, which is typical for the States of Near-East region namely for Lebanon and Syria. The solid combined S.P.D., which are under discussion in the article presented have the geometrics, which follow the Sun path over the sky vault, thus having a non-traditional curved outlines. It is stated, that they not only satisfy a sunprotection requirements efficiently, but also add an aesthetic qualities to the facades of buildings considered. In the article the calculations of geometrics for the S.P.D. in question for different orientation aspects of windows are given. These devices can improve the energy efficiency of the building.

Shear Strength of Compacted Clays as Affected by Mineral Content and Wet‐Dry Cycles

The behaviors of high‐plasticity clays depend largely on the clay mineral content. Recently, it has been observed that sudden slope failures of most clay slopes occur in regions pronounced with repeated rainfall and sunny climate. The reason for this is still unclear. Examining the effect of clay minerals and drastic weather changes on shear strength will be useful in predicting the performance of structures built in such soils and to take precautionary measures to improve the properties before failure. Therefore, a series of quick direct shearing tests were conducted on 11 artificial clay mixtures. The cohesion and frictional strength properties were determined and linked to the proportion of clay minerals and the number of wetting and drying cycles. The results show a significant reduction in shear strength after exposure to wetting and drying. Generally, montmorillonite‐dominated mixtures were less susceptible to the changes in cohesion strength than kaolin‐dominated mixtures, and the reduction in frictional strength was relatively insignificant.

Venetian blinds as a version of sun-shelves to be used in hot and sunny climate conditions

Light-shelves, as a mean to distribute sun-ray’s flows, can be considered as a minor parts of venetian blinds. Light shelves, acting as light- spreading devices, spread sun light rays, transformed into diffuse light flows into the depth of a promise. The same function possesplanks of venetian blinds, though they have a much less geometry sizes. The aim of the investigations presented is to determine the optimum size of these planks and distance between them in order to ensure a maximum natural lighting of interiors under different sort of lighting, which is associated with different climatic regions or with different seasons of a year. The proposed solutions allow reducing electric power consumption in buildings.

Design and Fabrication of Solar Bicycle

Since the fuel prices are increasing day by day not only in India but also throughout the world, hence, there is a tremendous need to search for an alternative to conserve these natural resources. Thus, a solar bicycle is an electric vehicle that provides an alternative by harnessing solar energy to charge the battery and thus provide required voltage to run the motor. Since India is blessed with nine months of sunny climate thus concept of solar bicycle is very friendly in India. Hybrid bicycle combines the use of solar energy as well as the dynamo that runs through pedal to charge the battery to run the bicycle. Thus, solar hybrid bicycle can become a very vital alternative to the fuelled automobile, hence, its manufacturing is essential.

Automatic Parametrization and Shadow Analysis of Roofs in Urban Areas from ALS Point Clouds with Solar Energy Purposes

A basic feature of modern and smart cities is their energetic sustainability, using clean and renewable energies and, therefore, reducing the carbon emissions, especially in large cities. Solar energy is one of the most important renewable energy sources, being more significant in sunny climate areas such as the South of Europe. However, the installation of solar panels should be carried out carefully, being necessary to collect information about building roofs, regarding its surface and orientation. This paper proposes a methodology aiming to automatically parametrize building roofs employing point cloud data from an Aerial Laser Scanner (ALS) source. This parametrization consists of extracting not only the area and orientation of the roofs in an urban environment, but also of studying the shading of the roofs, given a date and time of the day. This methodology has been validated using 3D point cloud data of the city of Santiago de Compostela (Spain), achieving roof area measurement errors in the range of ±3%, showing that even low-density ALS data can be useful in order to carry out further analysis with energetic perspective.

Modeling a Tropical Urban Context with Green Walls and Green Roofs as an Urban Heat Island Adaptation Strategy

Abstract Urban green infrastructure (UGI) has gained increasing attention as urban heat island (UHI) mitigation and resilience strategy recently. This preliminary study investigates the outdoor temperature behavior with different fractions of selected UGIs, in tropical Colombo, the commercial capital Sri Lanka with a computer based simulation for a hot, humid end–summer sunny climate conditions in August. Seven UGI scenarios were defined under real scale modeling by ENVI–met, as T1 (existing UHI), green roofs T2,T3,T4 and green walls T5,T6,T7 by considering vegetation percentage and existing geometry. Outdoor temperatures were measured in three different locations using receptors (R1, R2 and R3) by considering the positioning with building walls and asphalt roads in the sensible height of 1.5m. Software was validated with 0.9657 R2 for simulated versus real ground measurements for T1 in same location initially. Results have enlightened that different green infrastructures significantly reduced the temperature with the vegetative fraction and highest reduction of outdoor air temperature was recorded at 1500h in a typical day. R1 and R3 had given the best reductions of temperature by 2.03°C and 1.88°C, respectively at green wall for 100% in East–West direction while R2 temperature reduction was 1.64°C for green roof 100% compared to existing UHI scenario (T1).

Scale-Model And Simulation-Based Assessments For Design Alternatives Of Daylight Redirecting Systems In A Side-Lighting Educational Room

Daylight has been proven to have positive effects on well-being, comfort and performance of occupants in buildings; it specifically increases learning performance in educational buildings. Side-lighting from one direction leads to unbalanced and insufficient illuminance, especially in large and deep spaces. A design studio at the Izmir Institute of Technology (IZTECH) in Urla, Turkey, has been chosen as an example of a space in such a context. Its geometrical attributes has taken to be the baseline. First, four daylight redirecting systems are applied on its 1/15 scale model to understand and compare their redirection behavior visually. Second, measurements on the scale model are taken to compare the daylight illuminance distributions. Third, to assess the overall performance in the sunny climate, illuminance and luminance maps for photorealistic visualization are calculated in monthly steps over one year. For efficient calculation of the time-steps to be considered, the daylight coefficient method has been applied. Though light ducts are found to be effective for high sun angles, in summer and equinoxes; very low illuminance in entire space make them fail in winter. Light shelves are determined to be the most convenient ones for this space, since they provided sufficient, uniform and high illuminance in equinoxes and winter.

Technical and economic evaluation of thin-film CdTe building-integrated photovoltaics (BIPV) replacing façade and rooftop materials in office buildings in a warm and sunny climate

Abstract A great challenge and trend for sustainable buildings is to reduce electricity consumption, and at the same time try to supply their own energy demand with self-generation. The project should be development focused on sustainability, explore the passive strategies and the energy generation potential of facades and roof. In this paper we analyze for the first time in Brazil and under current solar photovoltaic (PV) module prices, the technical and economic potential of integrating state-of-the-art, frameless, glass-glass thin-film cadmium telluride (CdTe) PV modules on a commercial building facade and roof, and evaluate the economic feasibility of replacing traditional facade materials like architectural glass and aluminum composite material with sleek black PV modules in six Brazilian cities. The technical analysis consisted in evaluating the energy performance of a four-storey office building for each of the six cities under analysis. The technical analysis showed that it is possible to fully meet the energy demand of the office building with PV integration in all the Brazilian cities evaluated. While the local climate has a significant impact on the energy consumption due mostly to air conditioning loads, PV energy production follows the same trend. Most importantly, the economic analysis showed that with the declining costs of photovoltaics, replacing conventional facade building materials with PV modules is not only an innovative approach but also of economic benefit.

Globalisation, money, taxes – past and present

The article is devoted to changes that have taken place in the world economy and in the econo- mics, starting with the Great Depression of the 1930s to the contemporary Global Crisis. The author pays special attention to the phenomenon of free movement of capital across borders, which lead to weakening of the importance and role of the state.

Stationary Outdoor Sun-Protective Canopies as a Mean of Improving Of Lighting Environment in the Premises of Civil Buildings in the Hot and Sunny Climate with Clear Sky Conditions

Stationary Outdoor Sun-Protective Canopies as a Mean of Improving Of Lighting Environment in the Premises of Civil Buildings in the Hot and Sunny Climate with Clear Sky Conditions

Is the average photon energy a unique characteristic of the spectral distribution of global irradiance?

The average photon energy (APE) has become a popular index to qualitatively assess whether shorter or longer wavelengths are enhanced in a specific spectral distribution of irradiance when compared to the AM1.5G standard spectrum. According to some previous assessments, this index might uniquely distinguish individual global tilted irradiance and global horizontal irradiance spectra. This paper basically applies the same methodology as that used in these studies, i.e., a statistical analysis based on spectral distributions grouped in 0.02-eV APE bins and their standard deviation across all 50-nm bands into which the wavelength range under scrutiny (350–1050nm) is divided. Two years of spectral global tilted irradiance datasets collected at two Spanish locations, 333km apart, are analyzed here. The same brand and model of spectroradiometer is used in each site with identical experimental protocols. It is found here that the coefficient of variation—a more meaningful statistical coefficient than the standard deviation to quantify dispersion around the mean—remains below 3.3% over the 450–900-nm waveband, whereas values up to 5–11% occur outside of it. It is shown that these higher values can be explained by the separate or combined impacts of experimental uncertainty and the direct effect of aerosols and water vapor. Based on radiative transfer principles related to these two atmospheric constituents, it is argued that APE cannot be a unique characteristic of the complete spectrum, thus confirming previous results that pertained to direct irradiance only. In practical terms, however, it is reasonable to ascertain that APE may be considered approximately unique relative to the spectrum distribution under the climate of the two sites under scrutiny over the limited 450–900-nm spectral range. This conclusion presumably holds for most of Spain, or even for locations with sunny inland climates similar to those of Jaén and Madrid.

Multi-criteria analysis for the integrated performance assessment of complex fenestration systems

ABSTRACTComplex fenestration systems (CFS) designed to collect and redirect daylight from the sky-vault are generally placed on the upper part of a window in order to improve the distribution of indoor daylight. Due to their additional function as solar protection, their use might contribute to the mitigation of the unfavourable effects that the admission of daylight signifies, especially in buildings located in prevailing sunny climates (risk of glare and overheating). An appropriate selection of the CFS that better contributes to improve the interior daylight environment would imply an integrated performance assessment taking into account relevant aspects such as indoor daylight distribution and the visual and thermal comfort of occupants. However, such an assessment implies the use of performance criteria with different targets; therefore, in order to evaluate their overall performance, a multi-criteria analysis is applied in this study. The method presented here describes a comprehensive evaluation to determine those CFS that better contribute to an improved indoor daylighting environment in a building located in a prevailing sunny climate. The CFS performance assessment was undertaken with computer simulations using their bi-directional transmission distribution function (BTDF).

The relationship between vitamin D status and muscle strength in young healthy adults from sunny climate countries currently living in the northeast of Scotland.

Vitamin D has been suggested to play a role in muscle health and function, but studies so far have been primarily in older populations for falls prevention and subsequent risk of fractures. Vitamin D status was assessed in a healthy young adults from sunny climate countries (n=71, aged 19-42years) with 56% seen within 3months of arriving in Aberdeen [newcomers; median (range) time living in the UK=2months (9-105days)] and the remainder resident for >6months [residents; 23months (6-121months)]. Participants attended visits every 3months for 15months. At each visit, fasted blood samples were collected for analysis of serum 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), carboxy-terminal collagen crosslinks (CTX) and N-terminal propeptide of type I collagen (P1NP). Maximal voluntary contractions (MVC) were performed for grip strength (both arms) and for maximal isometric strength of the knee extensors (right knee). There were small seasonal variations in 25(OH)D concentrations within the newcomers and residents, but no seasonal variation in bone turnover markers. There was a positive, albeit small, association between 25(OH)D and knee extensor maximal isometric strength. Mixed modelling predicted that for each 1nmol/L increase in 25(OH)D, peak torque would increase by 1Nm (p=0.04). This study suggests that vitamin D may be important for muscle health in young adults migrating from sunnier climates to high latitudes, yet the potential effect is small.

Performance assessment issues in utility-scale photovoltaics in warm and sunny climates

With the declining costs of photovoltaics (PV), and the excellent solar energy resource availability in the country, the Brazilian government and the electricity sector have started to evaluate and consider PV as a serious potential contributor to the National electricity mix. Since the late 1990s, Brazilian electrical utilities are required by the National Electrical Energy Regulatory Agency ANEEL to invest 1% of their operational income on R&D. In 2011 ANEEL issued an R&D call dedicated to utility-scale PV. The solar energy research group at Universidade Federal de Santa Catarina (www.fotovoltaica.ufsc.br) has been actively investigating and promoting PV in Brazil, operates since 1997 the first grid-connected, thin-film PV generator in the country. Under the ANEEL R&D call, a 4-year, US$ 20 million project was started in 2012. The project aims at assessing the performance of seven different PV technologies at eight different Evaluation Sites (ES) in Brazil, and also to design, procure, install and monitor the performance of a utility-scale 3 MWp R&D PV power plant, which is located at one of these eight ES. The 3 MWp PV power plant and all the eight ES are fully monitored, with all electrical and environmental parameters measured at 1-s intervals. PV technologies include thin-film amorphous silicon (a-Si), microcrystalline silicon (μ c-Si), cadmium telluride (CdTe), copper indium gallium diselenide, mono- and multi-crystalline silicon (c-Si and m-Si), all at fixed tilt, as well as double-axis tracking, concentrated PV using triple-junction InGap/GaAs/Ge at 820 suns concentration. All ES are identical, except for the fixed PV arrays tilt angle, which is equal to the latitude at each site. The 3 MWp R&D PV power plant is co-located at one of the ES sites. Thin-film PV technologies with a low temperature coefficient of power presented superior output performance, and cloud-edge and cloud-enhancement effects of solar irradiance resulted in operational issues that were not previously described in the literature. Inverter Loading Ratios commonly described in the literature (for less sunny sites) led to considerable annual energy losses.

The impact of silicon solar cell architecture and cell interconnection on energy yield in hot & sunny climates

A series resistance induced by cell interconnections will lead to a worse TCPMPP of solar modules compared with cells.

Photoaging Photography

One of the major sources for children to gain knowledge of skin-protective measures is from their parents. Therefore, an imperative exists for parents to model and reinforce the sun-safety practices they want their children to adopt. Although Australian mothers have been the recipients of two extensive sun-safety public health campaigns, little is known about their attitudes, behaviors, and application of health promotion knowledge toward their and their child’s ultraviolet (UV) sun exposure. Ten mothers with children aged 4 to 12 years were asked a series of questions about their sun-safety practices, both pre- and post-viewing an UV photoaged photograph of their and their child’s face. Interpretive Phenomenological Analysis identified four themes and 12 subthemes. The findings reveal that mothers expressed divergent views on skin protection pre- and post-inspecting their and their child’s photoaged photographs. At one end of the viewing spectrum, mothers expressed an opinion that some degree of skin damage was an inevitable reality in Australia’s sunny climate, and on the other end of the viewing spectrum mothers expressed their desire to keep themselves and their child out of the sun. Mothers in the mid-range of the spectrum stated that their parenting task was one of transferring the responsibility for adopting skin-protective measures from themselves to their preteen children. The combination of mothers viewing their own photos as well as their child’s photograph serves to enhance the difference seen in photoaging damage, which in turn provides greater impetus for mothers to be concerned about photoaging in general.

Residential Rain Garden Performance in the Climate Zones of the Contiguous United States

AbstractRain gardens are one of the technologies often recommended for residential stormwater management. It is not difficult to find rain garden design recommendations, but more difficult to find quantitative assessments of how effective these gardens are at reducing runoff. Analysis is presented to illustrate how well a common rain garden design would work when subjected to the hydrological and meteorological extremes experienced across the contiguous United States. Results of 3-year hourly continuous simulations indicate that, because of variations in the amount and pattern of precipitation, the effectiveness of comparable rain gardens would vary from about 51.3 to 99.8% across the contiguous United States. Identical gardens would be least effective in Atlantic and Gulf Coast states and most effective in northern Midwest and Mountain states. Results also indicate garden evapotranspiration and evaporation have a negligible impact (<1%) on runoff reductions. This is true even for the warm, sunny climates...

Daylight Utilization with Light Pipe in Farm Animal Production: A Simulation Approach

Light pipes offer a passive way to bring daylight inside deep buildings, such as agricultural buildings. However, the lack of reliable performance predictability methods for light pipes represents a major obstacle preventing their widespread use. This paper evaluates a simulation approach for performance prediction and identifies key light pipe design parameters affecting their daylight transmission performance. The study was carried out through continuous monitoring of daylight in two full-scale, identical pig stables fitted with two light pipe systems, Solatube® and Velux®. The experiment included three continuously measuring sensors in each stable and an outdoor sensor during 2013 and 2014. A forward raytracing tool, TracePro®, was used for illuminance prediction and parametric simulations. The simulation results for overcast skies indicated discrepancies between the simulated and average measurement results below 30% in all cases. The discrepancies for clear skies were somewhat higher, i.e., below 30% for 67% of the cases. The higher discrepancies with clear skies were due to the overestimation of absolute sunlight levels and absence of an advanced and detailed optical characterization of the dome collector’s surface. The parametric results have shown that light pipes’ performance is better during summer time, in sunny climates, at low to mid-latitudes, which provides higher solar altitudes than during winter and cloudy climates at high latitudes. Methods to improve the luminous transmittance for low solar altitudes occurring in Scandinavia include: bending or tilting the pipe, increasing the aspect ratio, improving the pipe specular reflectance, tilting the collector to the south, and using optical redirecting system in the collector. (Less)

TRNSYS Simulation of a Solar Cooling System for the Hot Climate of Pakistan

Cooling is a basic need for buildings in hot and sunny climates. In most countries the major source of cooling is electrical power based. During summer in hot climates there is an increase in electricity consumption due to cooling load. Pakistan is facing an electricity shortage crisis, which becomes worse in summer due to the high demand for cooling. The annual average insolation for Pakistan is 5-6 kWh/m2/day, reaching 6-8 kWh/m2/day in summer with sunshine of 10-13hours a day, which gives suitable conditions for solar powered cooling system operation. TRNSYS software provides the possibility to simulate a complete solar air conditioning system integrated with a building. In this study, TRNSYS is used to model an absorption chiller operated by hot water from an evacuated tube collector. It is found that, with a hot water storage tank, a collector area of 12 m2 is sufficient to maintain the temperature in a room in a typical house at or below 26°C during the cooling season.

Thermo-economic analysis of conventional combined cycle hybridization: United Arab Emirates case study

Extensive investigations have been conducted to find a replacement for fossil fuels and natural gases in power generation industries. Solar energy is one of the most promising solution to a more environmentally friendly power production technology. In particular, concentrated solar power technologies are displaying significant potential for electricity production. United Arab Emirates hot and sunny climate is an indication of the great potential it possesses for hybrid and solar only power plant implementation. In this paper, power plant hybridization feasibility in the United Arab Emirates is taken under extensive investigation. Moreover, a thermo-economic optimization is performed for the installment of a new 50MWe hybrid conventional combined cycle power plant in the United Arab Emirates. In addition, hybridization of an already existing conventional combined cycle power plant is comprehensively investigated by utilizing levelized cost of electricity, payback period, life cycle saving, and net present value approaches. The hybrid conventional combined cycle power plant optimum levelized cost of electricity and net present value are 77.7US$/MWh and −34.918MUS$, respectively. Additionally, the plant solar share and specific carbon dioxide emission are 8.87% and 371.9kgCO2/MWh, respectively.