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With reference to energy generation, the global society has to urgently address three factors that are now critical: sustainability in terms of climate change, security in terms of the war that is currently raging in Europe with consequences that are being felt around the globe and the steep incline of fossil-fuel based energy costs. Around the world, large-scale solar farms are being constructed with tracking systems to improve the efficiency of photovoltaic (PV) modules. This article presents a comparison of energy generation of fixed-slope versus tracking PV modules. The analysis was based on a twenty-year dataset for two locations, namely, Lincoln (England) and Bhavnagar (India), which differ in terms of latitude, sky clarity and ambient temperature. It was demonstrated that a fixed-slope system facing the equator provides a healthy energy receipt that is a high fraction of the energy receipt of a tracking system. Furthermore, analysis was also carried out for a PV facility that will host the largest solar farm in England to conclude that regardless of the solar farm installation location, the use of bifacial PV is beneficial. [ABSTRACT FROM AUTHOR]

Depleting energy resources, enhancing energy security and energy access and approaching climate change related challenges are some of the present day challenges. Against this backdrop, renewable energy (RE)-based farming has been a topic of serious discussion within Great Britain and Scotland. There are multiple advantages in the development and applications of RE micro-grids for farming communities as often they are located in areas that are quite remote and hence their energy sustainability provides security of supply. In the present article, a large-scale RE system that included solar photovoltaic and wind turbine has been critically analyzed with respect to its fractional contribution toward the total energy budget of a potato farm that produces 8000 tons of crops annually, with 4500 tons of the produce in cold storage for up to 8 months. The findings and recommendations from these case studies will help renewable energy practitioners in erecting and analyzing similar installations. [ABSTRACT FROM AUTHOR]

Solar photovoltaic technology is one of the renewable technologies, which has a potential to shape a clean, reliable, scalable and affordable electricity system for the future. This article provides a comprehensive review of solar photovoltaic technology in terms of photovoltaic materials efficiency and globally leading countries. Based on past years review and photovoltaic installations in the year 2014, the major five leading countries identified are China, Japan, USA, Germany and UK. These five countries altogether accounted for 80% of photovoltaic installations in 2014. The article also discusses the driving policies, funding and Research and Development activities: to gauge the reasons behind the success of the leading countries. Finally, this article reviews the photovoltaic cost analysis in terms of the photovoltaic module cost, balance of system cost and project cost with the help of listed 98 globally installed projects. [ABSTRACT FROM AUTHOR]

Authorities in Slovenia and other EU member states are confronted with problems of city transportation. Fossil-fuel-based transport poses two chief problems--local and global pollution, and dwindling supplies and ever-increasing costs. An elegant solution is to gradually replace the present automobile fleet with electric vehicles (EVs). This article explores the economics and practical viability of the provision of solar electricity for the charging of EVs by installation of economical available Photovoltaic modules. A steep decline in the module, inverter and installation costs is reported herein. Present estimates indicate that for the prevailing solar climate of Celje--a medium-sized Slovenian town--the cost would be only 2 euros and 11 cents per kWh of generated solar electricity. [ABSTRACT FROM AUTHOR]

This article presents modeling and experimental verification of conversion of solar irradiation from horizontal to sloped surfaces and photovoltaic cell temperature and an analysis of photovoltaic conversion efficiency. Modeling and validation of the models are carried out on the basis of measurements conducted using the experimental system set in a city in southern Turkey. In addition to current, voltage, and cell temperature of the photovoltaic module, environmental variables such as ambient temperature and solar irradiance were measured and used for validation purposes. Correlation of conversion of solar irradiation from horizontal to sloped surfaces indicated that the presently used model is highly successful because of the fitting parameters: the coefficient of determination , and the mean bias error . Similarly, the cell temperature model used in the present article is validated by the following correlation parameters: , , and root-mean-square error . [ABSTRACT FROM AUTHOR]

Transport and its energetic and environmental impacts affect our daily lives. The transport sector is the backbone of the United Kingdom's economy with 2.3 million people being employed in this sector. With a high dependency on transport for passengers and freight and with the knowledge that oil reserves are rapidly decreasing a solution has to be identified for conserving fuel. Passenger vehicles account for 61% of the transport fuel consumed in the U.K. and should be seen as a key area to tackle. Despite the introduction and development of electric powered cars, the widespread infrastructure that is required is not in place and has attributed to their slow uptake, as well as the fact that the electric car's performance is not yet comparable with the conventional internal combustion engine. The benefits of the introduction of kinetic energy recovery systems to be used in conjunction with internal combustion engines and designed such that the system could easily be fitted into future passenger vehicles are examined. In this article, a review of automobile kinetic energy recovery system is presented. It has been argued that the ultracapacitor technology offers a sustainable solution. An optimum design for the urban driving cycle experienced in the city of Edinburgh has been introduced. The potential for fuel savings is also presented. [ABSTRACT FROM AUTHOR]

The article presents a study on the classification of the 15 International Commission on Illumination (CIE) Standard Skies. It states that the study uses the probabilistic neural network (PNN) to categorize the skies which show unique luminance distribution. It mentions that the study employs five meteorological variables as input data including solar altitude, zenith luminance, and direct-beam. Moreover, the study found that the PNN is efficient for sky classification.

Delta-T Device Limited of Cambridge, UK have developed an integrated device which enables simultaneous measurement of horizontal global and diffuse irradiance as well as sunshine status at any given instance in time. To evaluate the performance of this new device, horizontal global and diffuse irradiance data were simultaneously collected from Delta-T device and Napier University's CIE First Class daylight monitoring station. To enable a cross check a Kipp & Zonen CM11 global irradiance sensor has also been installed in Currie, south-west Edinburgh. Sunshine duration data have been recorded at the Royal Botanical Garden, Edinburgh using their Campbell-Stokes recorder. Hourly data sets were analysed and plotted within the Microsoft Excel environment. Using the common statistical measures, Root Mean Square Difference (RMSD) and Mean Bias Difference (MBD) the accuracy of measurements of Delta-T sensor's horizontal global and diffuse irradiance, and sunshine duration were investigated. The results show a good performance on the part of Delta-T device for the measurement of global and diffuse irradiance. The sunshine measurements were found to have a lack of consistency and accuracy. It is argued herein that the distance between the respective sensors and the poor accuracy of Campbell-Stokes recorder may be contributing factors to this phenomenon. [ABSTRACT FROM PUBLISHER]

This paper examines the feasibility of desiccant cooling in UK climates, using gas-solar hybrid technology for regeneration. Desiccant cooling is a heat driven system. It has potential to reduce energy costs and environmental pollution, when compared with conventional vapour compression systems. The regeneration of the desiccant can be provided by any low temperature warm air or water source including waste heat, CHP, gas or solar. Heat recovery is also available. Gaia Research worked with Napier University to develop computer codes for the simulation of solar energy collection and hot water delivery to drive the desiccant cooling system, based on real meteorological data. A solar desiccant computer model was developed with the University of Leeds which analysed the energy consumption and costs associated with desiccant cooling using meteorological data for an inner London site in 1994. The study demonstrates that coupling the desiccant system to solar collectors produces significant savings in both running cost and CO2 emissions. The existing models of solar contribution and desiccant cooling will be refined. This will enable an assessment to be made of the UK opportunities for energy conservation and CO2 emission reduction in relation to latitude, internal design conditions, and real loads. Cet article traite des possibilites de realisation de systemes de refroidissement par deshydratation dans les conditions climatiques propres au Royaume-Uni, en faisant appel a la technologie hybride gaz-energie solaire pour la regeneration. Compares aux solutions classiques de compression de vapeur, de tels systemes de refroidissement, bases sur la puissance thermique, permettent de reduire les couts energetiques et de diminuer la pollution environnementale. La regeneration du deshydratant peut etre assuree par toute source d'eau ou d'air chauffee faiblement: chaleur perdue, CHP, gaz ou energie solaire. Le Groupe Gaia Research et l'Universite Napier ont travaille ensemble au calcul de codes informatiques pour simuler le captage de l'energie solaire ou la fourniture d'eau chaude pour alimenter le systeme de refroidissement par deshydratation en fonction de donnees meteorologique brutes. Avec l'Universite de Leeds, ils ont mis au point un modele de deshydratant solaire qui analyse la consommation energetique et les couts du refroidissement par deshydratation; ce modele utilise des donnees meteorologiques recueillies a Londres en 1994. Cette etude demontre que l'association d'un systeme deshydratant a des capteurs solaires degage des economies non negligeables au niveau des couts d'exploitation et reduit sensiblement les emissions de CO2. Les modeles existants, bases sur la contribution de l'energie solaire et du refroidissement par deshydratation, seront ameliores et serviront a evaluer les possibilites pour le Royaume-Uni de faire des economies d'energie et de reduire les emissions de CO2 en fonction de la latitude, des parametres de conception et des charges reelles. [ABSTRACT FROM AUTHOR]

This paper analyses Seville's surface urban heat island (SUHI) phenomenon, comparing spatial and temporal patterns of land surface temperature (LST) during July 1987, 2000 and 2017. Landsat data captured throughout three July months were analyzed for the different years, techniques of geographic information systems, ecological variables and geospatial approaches and used to carry out the analysis. The results indicate that from 1987 to 2017, the averaged LST has increased by 9.1 °C in the studied area. The urban areas are colder than their surroundings, suggesting the role of baresoil and cultivated land in the reversal of the SUHI phenomenon. The results show that a fraction of green space has a high unstandardized coefficient (β) through the three time periods. A decreasing trend is also observed in the standardized β "fraction of impervious surface" in the three time periods. The linear regression analysis shows a negative relationship of mean LST with impervious surface fraction due to the presence of shadows projected by buildings, and a positive relationship with green space fraction caused by the influence of baresoil and cultivated land that inverts the LST behavior pattern. The study concludes that there is a need to implement SUHI mitigation strategies during the initial phases of engineering projects where the origin of this problem can be acted upon, since the process of creating streets and public space offers a valuable opportunity to restore the environmental quality and diminish the effects generated by climate change. [ABSTRACT FROM AUTHOR]

There are a large number of engineering applications wherein estimation of radiation exchange between surfaces is required. One important part of the latter procedure is to obtain the so-called 'view factor' of the emitter–receiver combination. The principal aim of this article is to present finite-element based procedures to obtain view factor with good time efficiency. As such routines presented here compute the view factor between a non-uniform emitter field and the receiving surface. An example of this is ground-reflected solar radiation to thermal or photovoltaic collectors, the foreground itself being composed of surfaces that have wide-ranging reflectivities. Four routines have been presented here: one based on a uniform grid for emitting and receiving surfaces using a brute force approach (Uniform Populous Grid (UPG)), and another that used non-uniform grid for the receiving surface, where cells' sizes increased in arithmetic progression as one withdraws from the common edge (Non Uniform Grid Populous (NUGP)). The last two routines used combinations of the first two approaches with Monte-Carlo approach (Uniform Grid Monte-Carlo (UGMC) and Non Uniform Grid Monte-Carlo (NUGMC)). It was found that the NUGP algorithm was the most efficient to reduce the calculation error for the same number of computations, it was about 450 times (430 for non-uniform reflectivity) more accurate than UPG, 160 (125) times more than UGMC and 70 (60) times more than NUGMC. Finally a comparison of advantages and disadvantages of all four considered routines was added, using the following criteria: ease of programming, computational execution time, accuracy of results obtained, and predictability of the errors. [ABSTRACT FROM AUTHOR]

Accurate solar radiation data are essential for the development of solar energy application systems. The limited availability of solar radiation data, and especially diffuse irradiance values, makes it vital to develop models to estimate these data. The development of estimation models has been the objective of many studies. This paper presents an extended review of the diffuse ratio (k) vs. clearness index (kt) annual, monthly, daily, and hourly frequency regression models. It is however interesting to note that there is a dearth of such knowledge for diffuse ratio–clearness index regressions that are based on averaged data. Monthly-averaged daily global irradiation data are now easily available from the NASA website for any global location. Using existing models, it is possible to decompose the daily to averaged-hourly global irradiation values. The missing link so far has been hourly averaged diffuse irradiation. This article presents regression equations which could be used to estimate that information. For this purpose, hourly global and diffuse irradiation data was pooled from 19 different locations to obtain three latitude-dependent regression models relating the monthly-averaged hourly diffuse ratio ( k ¯ ) to the clearness index ( k t ¯ ). The results show a high relationship between both variables. These regression equations could be used to estimate the averaged diffuse irradiation values from averaged global irradiation values, which are more easily available. [ABSTRACT FROM AUTHOR]

The island of Sark, located in the English Channel, has endured an electricity distribution crisis for the past few years, resulting in high electricity costs almost six times higher than UK mainland energy prices. This article is focused on a methodology for finding the best renewable energy system with the lowest levelized cost of energy (LCOE) in comparison to the current energy rate of 66 p/kWh. Three different main cases of study have been compared in performance for different levels of renewable energy integration and energy storage, evaluating the estimated size of the system, installation cost and CO2 emissions. The results, which depend on the assumptions outlined, show that Case 2 renewable energy generation system is the most suitable in terms of reduction of CO2 emissions and expected earnings from a lower LCOE. Uncertainty in the results could be minimized if actual data from the island is made available by following the same methodology to find the best solution to the island's current energy generation problem. Due to non-available data for the load profiles and wind velocity a set of assumption were required to be implemented. As such, two different load profiles were selected—one with a peak of energy consumption in winter and the other with a summer peak. [ABSTRACT FROM AUTHOR]

Computation of view factors is required in several building engineering applications where radiative exchange takes place between surfaces such as ground and vertical walls or ground and sloping thermal or photovoltaics collectors. In this paper, view factor computations are performed for bifacial solar photovoltaic (PV) collectors based on the finite element method (FEM) using two programming languages known as Microsoft Excel-Visual Basic for Applications (VBA) and Python. The aim is to determine the computer response time as well as the performance of the two languages in terms of accuracy and convergence of the numerical solution. To run the simulations in Python, an open source just-in-time (JIT) compiler called Numba was used and the same program was also run as a macro in VBA. It was observed that the simulation response time significantly decreased in Python when compared to VBA. This decrease in time was due to the increase in the total number of iterations from 400 million to 250 billion for a given case. Results demonstrated that Python was 71–180 times faster than VBA and, therefore, offers a better programming platform for the view factor analysis and modelling of bifacial solar PV where computation time is a significant modelling challenge. [ABSTRACT FROM AUTHOR]

The main aim of this article is to present research findings related to the design of an electric rickshaw for use in Kolkata, India, identifying weaknesses in the current cycle rickshaw, developing a design solution to address problems found, and exploring the possibility of utilising solar power. Through research and testing it was found there were many design issues, concerns with health and safety, comfort, and ergonomics. All problems found were addressed by implementing design upgrades. The testing of the current cycle rickshaw identified the power and energy required to implement an electric drive system, where a 500 W 24 V DC motor and a battery capacity of 220 ampere hours was used in conjunction with a pedal assist system to provide a range of up to 52 km. A conceptual prototype was developed to prove the successful application of a pedal assist system, which was established as a viable option for design. The design has been critically evaluated and the relevant issues discussed. [ABSTRACT FROM AUTHOR]

Fuelled by energy security problems and urban air pollution challenges, several countries worldwide have set the objective to gradually eliminate petrol and diesel cars. The increasing support from government and demands for environmental friendly means of transportation are accelerating the use of battery electric vehicles. However, it is indispensable to have accurate and complete information about their behaviour in different traffic situations and road conditions. For the experimental analysis carried out in this study, three different electric vehicles from the Edinburgh College leasing program were equipped and tracked to obtain over 50 GPS and energy consumption data for short distance journeys in the Edinburgh area and long-range tests between Edinburgh and Bristol (UK). The results showed that the vehicles' energy intensities were significantly affected by the driving cycle pattern, with a noticeable diminution due to low temperatures. It was found that the real available range of the electric vehicle in some situations could be 17% lower than the predicted mileage shown in the dashboard of the vehicle. The difference from the New European Driving Cycle (NEDC) values was even higher. The study has also provided a discussion on the effect of the electricity mix on carbon emission reduction. [ABSTRACT FROM AUTHOR]

In the absence of ground reflected radiation measured data, an average albedo value of 0.2, which describes the reflective properties of the bare ground is generally used. The variation of albedo based on different foreground surfaces and under different atmospheric conditions is an area which is under research. This paper presents an experimental investigation of albedos of different foreground materials that can be used for photovoltaic (PV) applications. Overcast skies are predominant in northerly locations and will have a high frequency of low solar altitudes, and thus ground reflection is an important contributor towards total solar energy gain. The foreground surfaces include common materials: Grass, sand, and cement slabs, and some non-conventional materials: White pebbles, white boards, white tiles, and aluminium foil. The impact of factors, such as ageing, solar elevation, rain, and cloud cover (sky conditions) is analysed to determine the changes in albedos of these materials. Each material was observed to have individual performance characteristics under these factors. It was found that the non-conventional materials were least prone to weather-related changes and have higher albedo values as compared to the conventional materials, and also have good potential to replace the conventional materials for any given PV application. [ABSTRACT FROM AUTHOR]