Wind power potential assessment for seven buoys data collection stations in Aegean Sea using Weibull distribution function

This paper utilizes three hourly measured values of wind speed and direction from seven buoys data collection stations in Aegean Sea to study the wind speed and power characteristics applying the Weibull shape and scale parameters. Specifically, the site dependent, annual and monthly mean patterns of mean wind speed, Weibull parameters, frequency distribution, most probable wind speed, maximum energy carrying wind speed, wind power density and wind energy density characteristics have been studied. The Weibull distribution was found to represent the wind speed distribution with more than 90% accuracy in most of the cases. Slightly decreasing trends were observed in annual mean wind speed values at Lesvos and increasing at Mykonos. The mean values of wind speed, scale parameter, most probable wind speed, maximum energy carrying wind speed, wind power and wind energy density values showed higher values during winter time and lower in summer time. Mykonos was found to be the best site from wind power harnessing point of view. Moreover, the correlation between the percentages of times the wind speed was above cut-in-speed and the measured mean wind speed for the three selected sites and the correlation between the aforementioned percentages and the scale parameter c were examined and were found linear.http://jrse.aip.org/ai201

Offshore wind speed and wind power characteristics for ten locations in Aegean and Ionian Seas

This paper utilizes wind speed data measured at 3 and 10 m above water surface level using buoys at 10 stations in Ionian and Aegean Seas to understand the behaviour of wind and thereafter energy yield at these stations using 5 MW rated power offshore wind turbine. With wind power densities of 971 and 693 W/m2 at 50 m above water surface level, Mykonos and Lesvos were found to be superb and outstanding windy sites with wind class of 7 and 6, respectively. Other locations like Athos, Santorini and Skyros with wind power density of more than 530 W/m2 and wind class of 5 were found to be the excellent sites. Around 15–16% higher winds were observed at 10 m compared to that at 3 m. Lower values of wind speed were found during summer months and higher during winter time in most of the cases reported in the present work. Slightly decreasing (∼2% per year) linear trends were observed in annual mean wind speed at Lesvos and Santorini. These trends need to be verified with more data from buoys or from nearby onshore meteorological stations. At Athos and Mykonos, increasing linear trends were estimated. At all the stations the chosen wind turbine could produce energy for more than 70% of the time. The wind speed distribution was found to be well represented by Weibull parameters obtained using Maximum likelihood method compared to WAsP and Method of Moments.http://www.ias.ac.in/jess/ai201

Effects of heavy metal ions on white clover (Trifolium repens L.) growth in Cd, Pb and Zn contaminated soils using zeolite

According to the Greek Ministry of Environment, there are 2,000 contaminated sites in Greece. The agricultural production in these sites should be evaluated to provide an assessment and recommendations on the necessary actions required for crop sustainability. This study investigated the effects of heavy metals on White clover (Trifolium repens L.) growth in an above-referenced multi-metal contaminated site in the absence/presence of zeolite as an agent empowering the rehabilitation of pollution and immobilization of heavy metals. The addition of 1% zeolite to the polluted soils significantly contributed to plant growth by limiting the availability of Cd, Pb and Zn. However, the dry biomass of plants grown in the presence of zeolite was evaluated to be unsuitable as a raw material (feed) in livestock production, due to the high Cd toxicity. In the context of sustainable production, this study aims to holistically approach and evaluate mechanisms of phytoremediation, bioaccumulation and the disposal of the bioaccumulator as a high value-added product (feed)

Evaluating the Technical and Environmental Capabilities of Geothermal Systems through Life Cycle Assessment

In these days of heightened environmental consciousness, many countries are shifting their focus towards renewable energy sources for both large-scale uses (such as power plants that generate electricity) and smaller-scale applications (e.g., building heating and cooling). In this light, it is not surprising that there is a growing interest in technologies that are reliant on non-conventional sources of power, such as geothermal energy. This study is making an effort to provide a comprehensive understanding of the possible advantages and multiple uses of geothermal energy systems, in the context of their technical and environmental evaluation through Life Cycle Assessment. A brief description of the analyzing methods and the tools used to study a particular system or application is presented. The geothermal technologies and the applications of specific systems are discussed in detail, providing their environmental advantages and their technical barriers as well. District and domestic heating systems cover a significant fraction of the geothermal energy potential. The majority of the discussed studies cover the electricity production as the most important application of geothermal energy. The overall conclusion of the current work is that geothermal energy is an extremely viable alternative that, combined with other renewable energy systems, may mitigate the negative effects of the existing energy mix worldwide

Comparative effects of agricultural biowaste recycling practices and inorganic fertilization on basil (Ocimum basilicum L.) growth and soil fertility: Modelling plant growth

Introduction In modern societies, the disposal of ever more increasing biowaste is a serious threat [1]. Furthermore, the exploitation of soils that are unsuitable for cultivation (poor in nutrients due to intensive cultivation or polluted with organometallic pollutants) is an ongoing challenge [2]. One green and sustainable solution seems to be the disposal of biowaste, a rich source of nutrients, which might be exploited to produce biofertilizers in these soils [3-4]. The use of these organic amendments in agriculture is a common practice due to their ability to increase crop productivity, enhance soil health and improve soil physicochemical properties [5-6]. Methods This study investigates the effects of organic soil amendments with: compost from plants; chickens’ manure; sewage sludge; as well as a chemical fertilizer on basil (Ocimum basilicum L.) growth and soil fertility, whilst the expected effects of the abiotic and biotic environment, including effects of organic soil amendments, on plant growth were modelled using a Richards growth model [7]. Results The results showed that the best plant growth was achieved in the sludge-modified soils, whilst the poorest plant growth was noted in the chemical fertilizer-modified soil (Fig. 1). Moreover, the results of foliar diagnostics indexes showed that the plants of organic soil amendments with chemical fertilizer have low values, at the level of malnutrition, in several elements such as Phosphorus (P) and Copper (Cu) (Table 1). Conclusions This work confirms that the organic soil amendments generally result in beneficial effects with regard to plant growth and other soil properties. Our findings are significant for sustainable agriculture regarding the sustainable use of organic wastes in problematic soils. Acknowledgments: A part of the research project was co-funded by the University of Patras, in theframework of the program “MEDIKOS”. References [1] Giannakopoulos, E., et al., (2017). Jour. Environnemental Management, 195,186-194. [2] Ahmad, R., et al., (2007). Annals of Microbiology 57, 471-479. [3] Khadem, S.A., et al., (2010). Australian Journal of Crop Science, 4, 642-647. [4] Mullins, G.L., et al., (1996). Techn. Publication No. 424-034, Virginia State University, Blackburg, VA, USA. [5] Pervez, M.A., et al., (2000). International Journal of Agriculture and Biology, 2, 1-2. [6] Farrag, Κ., et al. (2016). Clean-Soil Air Water, 44 (9), 1174-1183. [7] Damgaard, C. (2004). Comptes Rendus Biologies,327(3),255-260

Investigating Thermal Performance of Residential Buildings in Marmari Region, South Evia, Greece

In recent decades, the steady increase of energy consumption from building construction and operations cause atmospheric pollution and significant financial burden, mainly due to the high costs imposed from energy production. This study examines ways under which modern designs of a building can be applied on construction and domestication while following conventional methods of construction, compared to a building that has been constructed and domesticated under bioclimatic architecture. Particularly, two buildings were investigated in terms of the energy consumption incurred, being built on the same seaside area and period of construction and at adjacent plots of the same distance from sea for ease of comparison. The first building (A1) was constructed under the principles of bioclimatic architecture, being also facilitated with green and smart technologies. The second building (A2) was constructed under conventional construction techniques. The energy efficiency of both buildings was calculated by the “TEE KENAK” software, while specific parameters were recorded. Energy classifications of both buildings were valued and a proposed scenario and interventions unveiled the energy classification upgrading from A2 to A1. Our analysis revealed, as also found in the literature, that during thermal energy oscillating conditions, corresponding relative humidity stresses were observed, indicating that the vapor pressure handling should be taken into account towards comfort. The preliminary incremental cost evaluation and comparison of A1 and A2 energy upgrading under the criterion of simple payback period were critically discussed

White Clover (Trifolium repens L.) Growth in multi-metal contaminated soils and Fate of Modern Pesticides

Introduction: Heavy metal binding to soil organic matter (1) is leading to soil contamination and plant bioaccumulation (2). Reducing the bioavailability of soil metals by adding amendments to the soil could be suitable for mitigating heavy metal uptake by plants (3-4). For example the addition of Zeolite at 1% dose in metal polluted soil was the most efficient way for reducing the average Cd concentration in tobacco plants, as reported by Keller et al. (5). Methods: In that same spirit, we investigated the effects of heavy metals (Pb, Cd, Zn) on White clover (Trifolium repens L. ) growth in an above-referenced multi-metal contaminated site in the absence and presence of zeolite as an agent empowering the rehabilitation of pollution and immobilization of heavy metals. Results: We demonstrated that White clover in soils with high heavy metal concentrations of Pb: 291, Cd: 4.3 and Zn: 1458 mg/kg soil acts as a “moderate” accumulator of Zn, Cd and “weak” accumulator of Pb (Fig. 1). The addition of 1% zeolite to the contaminated soils significantly contributed to plant growth by limiting the availability of Cd, Pb and Zn (Fig. 2), whilst the dry biomass of plants grown in the presence of zeolite was evaluated and found to be unsuitable as a raw material (feed) in livestock production. Conclusions: This study showed that contaminated soils must be evaluated for the necessary actions required for agricultural production. References: 1. Giannakopoulos, E. et al. (2005) J. Phys. Chem. A 109, 2223-2232. 2. Zhuang, P. et al. (2007) Water Air Soil Poll. 184, 235-242. 3. Prasad, R. et al. (2014) Afr. J. Biotechnol. 13, 705–713. 4. Ahmed, O.H. et al. (2010) Int. J. Phys. Sci. 5, 2393-2401. 5. Keller, C. et al. (2005) Plant Soil, 276, 69–84

Cool Pavements: State of the Art and New Technologies

With growing urban populations, methods of reducing the urban heat island effect have become increasingly important. Cool pavements altering the heat storage of materials used in pavements can lead to lower surface temperatures and reduce the thermal radiation emitted to the atmosphere. Cool pavement technologies utilize various strategies to reduce the temperature of new and existing pavements, including increased albedo, evaporative cooling, and reduced heat conduction. This process of negative radiation forces helps offset the impacts of increasing atmospheric temperatures. This paper presents an extensive analysis of the state of the art of cool pavements. The properties and principles of cool pavements are reviewed, including reflectivity, thermal emittance, heat transfer, thermal capacity, and permeability. The different types, research directions, and applications of reflective pavements are outlined and discussed. Maintenance and restoration technologies of cool pavements are reviewed, including permeable pavements. Results show that cool pavements have significant temperature reduction potential in the urban environment. This research is important for policy actions of the European Union, noting that European and international business stakeholders have recently expressed their interest in new ways of reducing energy consumption through technologically advanced pavements

Sustainable Urban Environment through Green Roofs: A Literature Review with Case Studies

This study conducts a literature review coupled with case-study calculations comparing the thermal contribution of semi-intensive and intensive (deeper) green roofs to non-insulated and insulated building roofs, and enhancing comprehension by validating applied scenarios with published literature-based data. Mitigation of the urban heat island is crucial for reducing energy consumption and enhancing urban sustainability, especially through natural solutions such as green (i.e., planted) roofs. The energy and environmental benefits of green roofs include energy conservation, thermal comfort, noise reduction, and aesthetic improvement. Legal mandates, innovative business models, financial subsidies and incentives, regulations, etc. are all components of green roof policies. Conflicts between private property owners and the public, regulatory gaps, and high installation costs are among the challenges. Green roofs are layered and incorporate interacting thermal processes. Green roof models are either based on the calculation of thermal transmittance (U-values), an experimental energy balance, or data-driven (primarily neural network) approaches. U-values were calculated for eight hypothetical scenarios consisting of four non-insulated and four insulated roofs, with or without semi-intensive and intensive green roofs of various materials and layer thicknesses. While the non-planted, non-insulated roof had the highest U-value, planted roofs were particularly effective for non-insulated roofs. Three of these scenarios were in reasonable accord with experimental and theoretical thermal transmittance literature values. Finally, a non-insulated planted roof, particularly one with rockwool, was found to provide a certain degree of thermal insulation in comparison to a non-planted insulated roof

Design, Energy, Environmental and Cost Analysis of an Integrated Collector Storage Solar Water Heater Based on Multi-Criteria Methodology

The paper presents a design and operation analysis of an Integrated Collector Storage (ICS) solar water heater, which consists of an asymmetric Compound Parabolic Concentrating (CPC) reflector trough, while the water tank comprises two concentric cylinders. The annulus between these vessels is partially depressurized and contains a small amount of water in the bottom of the outer vessel which dominantly contributes to the heat transfer from the outer to the inner cylinder. A multi-criteria optimization algorithm is applied to re-evaluate the design specifications of the parabolic surface, thus modifying the design of the entire ICS system and predict the necessary number of units for achieving the highest possible effectiveness with minimized fabrication costs and environmental impacts. The environmental footprint of the device is assessed through Life Cycle Assessment (LCA). The produced thermal energy in conjunction with the environmental and economic results are evaluated as a function of different configuration parameters regarding the water storage conditions, the solar radiation and the total pressure inside the annulus. The ultimate aim of the evaluation process is to offer new perspectives on the design principles of environmentally friendly and cost-effective devices with improved thermal performance