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The purpose of this paper is to propose a fixed PV energy system design and a sun tracking PV energy system design to meet the primitive energy demands of a typical house in Sakarya, Turkey with energy payback times (EPBT) and greenhouse payback times (GPBT) calculations.

The designs were developed based on the total solar radiation received on the surface of the PV modules. The EPBT and the GPBT of the designs were investigated by utilizing the current embodied energy data of the literature and annual energy output of the proposed systems. The monthly mean total solar radiation, the yearly total solar radiation and the annual energy output of the systems were calculated according to the results of previous studies of authors on 80-W prototypes of a fixed PV energy system tilted at the yearly optimum tilt angle of Sakarya and a two-axis sun tracking PV energy system.

The annual energy outputs of the fixed system and the tracking system were established to be 10.092 and 10.311 MJ, respectively. EPBT of the systems were estimated 15.347 years for the fixed system and 11.932 years for the tracking systems which were less than the lifespan of PV modules. The greenhouse gas emitted to produce and install the systems were estimated to be 6,899.342 kg for the fixed system and 5,040.097 kg for the tracking system. GPBT of the systems were calculated to be 5.203 and 2.658 years, respectively.

PV energy is clean without greenhouse gas emission during the operation. However, significant emissions occur in the life cycle of PV modules until the installation is completed. Therefore reducing the number of PV modules make great differences in the GPBT of PV energy systems. In this paper, comparisons between the GPBT results of the optimally tilted fixed system and tracking system were performed to discuss the best option by means of environmental concerns.

Priorities of decarbonizing the mining sector together with an availability of cost-effective technological solutions lead renewable energy (RE) to become an attractive energy source for the mining industry. Several pilot projects are run as hybrid systems, providing additional capacity to traditional energy systems. The purpose of this paper is to develop a mathematical model as a decision-making tool. The decision refers to a replacement of the fossil fuel system contains by the hybrid system in the sense of no return.

Four systems are considered. System one contains only a diesel plant. System two consists of a hybrid energy system with a photovoltaic (PV) part and a genset as back-up. System three includes a conventional natural gas combined cycle (CGCC) plant. Finally, system four covers a hybrid energy system with a PV part and CGCC turbine. The mathematical model is based upon the well-known concept of levelized cost of electricity.

The scenarios account for the degradation rate of PV modules, the PV yields of mines in different locations and the greenhouse gas emissions impact. The results show the break-even times of each scenario and the years of no return for the four systems in each scenario.

The solution of the model is performed for two case-studies. Case study 1 compares the diesel and hybrid PV-diesel systems. Case study 2 compares the CGCC and hybrid PV-natural gas systems.

This model can be generalized to all mining settings, with specific practical implications for off-grid mines.

The results of this paper bring a valuable contribution to carbon dioxide emissions reduction.

The paper aims to enhance the attention of decision-makers on fossil fuel and RE technologies increase the attractiveness of RE in powering mining operations.

Non-linear power–voltage characteristics of solar cell and frequently changing output due to variation in solar irradiance caused by movement of clouds are the major issues need to be considered in photovoltaic (PV) penetration to maintain the power quality of the grid. It is important for a PV module to always function at its maximum available power point to increase the efficiency and to maintain the grid stability. A possible solution to mitigate these generation fluctuations is the use of an electric double-layer capacitor or supercapacitor energy storage device, which is an efficient storage device for power smoothing applications. This study aims to propose a power smoothing control approach to smoothen out the output power variations of a solar PV system using a supercapacitor energy storage device.

To extract the maximum possible power from a PV panel, there are several maximum power points tracking (MPPT) algorithms developed in literature. Fuzzy logic controller-MPPT method is used in this work as it is a very efficient and popular technique which responds quickly under varying ecological conditions, reduced computational complexity and does not depend on any system constraints. Fuzzy logic-based MPPT controller by Boost DC–DC converter is developed for operating the PV panels at available maximum power point. Fuzzy logic-proportional integral (PI) charge controller is implemented by Buck–Boost converter to provide the constant current and suitable voltage for supercapacitor and to achieve better power smoothing. PI charge controller is preferred in this work as it offers better outcomes and is very easy to implement.

Simulation results conclude that the proposed power smoothing control approach can efficiently smooth out the power variations under variable irradiance and temperature situations. To confirm the accurateness of the proposed system, it is validated for poly-crystalline PV module and comparison of results is done by using different case study with and without the use of an energy storage system under change in irradiance condition. The proposed system is developed and examined on MATLAB/Simulink environment.

The performance comparison between PV power output with and without the use of a supercapacitor energy storage device under different Case Studies shows that the improved performance in smoothing of power output was achieved with the use of a supercapacitor energy storage device.

The Kingdom of Saudi Arabia (KSA) is facing a rapid growth in energy demand mainly because of factors like burgeoning population, economic growth, modernization and infrastructure development. It is estimated that between 2000 and 2017 the power consumption has increased from 120 to 315 TWh. The building sector has an important role in this respect as it accounts for around 80 percent of the total electricity consumption. The situation is imposing significant energy, environmental and economic challenges for the country. To tackle these problems and curtail its dependence on oil-based energy infrastructure, KSA is aiming to develop 9.5 GW of renewable energy projects by 2030. The campus of the King Fahd University of Petroleum and Minerals (KFUPM) has been considered as a case study. In the wake of recently announced net-metering policy, the purpose of this paper is to investigate the prospects of rooftop application of PV in buildings. ArcGIS and PVsyst software have been used to determine the rooftop area and undertake PV system modeling respectively. Performance of PV system has been investigated for both horizontal and tilted installations. The study also investigates the economic feasibility of the PV application with the help of various economic parameters such as benefit cost ratio, simple payback period (SPP) and equity payback periods. An environmental analysis has also been carried out with the help of RETScreen software to determine the savings in greenhouse gas emissions as a result of PV system.

This study examines the buildings of the university campus for utilizable rooftop areas for PV application. Various types of structural, architectural and utilities-related features affecting the use of building roofs for PV have been investigated to determine the corrected area. To optimize the performance of the PV system as well as space utilization, modeling has been carried out for both horizontal and tilted applications of panels. Detailed economic and environmental assessments of the rooftop PV systems have also been investigated in detail. Modern software tools such as PVsyst, ArcGIS and RETScreen have also been used for system design calculations.

Saudi Arabia is embarking on a massive solar energy program as it plans to have over 200 GW of installed capacity by 2030. With solar energy being the most abundant of the available renewable resource for the country, PV is going to be one of the main technologies in achieving the set targets. The country has, however, unlike global trends, traditionally overlooked the small-scale and building-related application of solar PV, focusing mainly on larger projects. This study explores the prospects of utilization of solar PV on building roofs. Building rooftops are constrained in terms of PV application owing to wide ranging obstacles that can be classified into five types – structural, services, accessibility, maintenance and others. The total building rooftop area in the study zone, calculated through ArcGIS has been found to be 857,408 m² of which 352,244 m² is being used as car parking and hence is not available for PV application. The available roof area, 505,165 m² is further hampered by construction and utilities related features including staircases, HVAC systems, skylights, water tanks and satellite dish antennas. Taking into account the relevant obstructive features, the net rooftop area covered by PV panels has been found to be in the range 25–41 percent depending upon the building typology, with residential buildings offering the least. To optimize both the system efficiency and space utilization, PV modeling has been carried out with the help of PVsyst software for both the tilted and horizontal installations. In terms of output, PV panels with tilt angle of 24° have been found to be 9 percent more efficient compared to the horizontally installed ones. Modeling results provide a net annual output 37,750 and 46,050 MWh from 21.44 and 28.51 MW of tilted and horizontal application of PV panels, sufficient to respectively meet 16 and 20 percent of the total campus electricity requirements. Findings of the economic analysis reveal the average SPP for horizontal and tilted applications of the PV to be 9.2 and 8.4 years, respectively. The benefit cost ratio for different types of buildings for horizontal and tilted application has been found to be ranging between 0.89 and 2.08 and 0.83 and 2.15, respectively. As electricity tariff in Saudi Arabia has been increased this year by as much as 45 percent and there are plans to remove $54bn of subsidy by 2020, the cost effectiveness of PV systems will be greatly helped. Application of PV in buildings can significantly improve their environmental performance as the findings of this study reveal that the annual greenhouse gas emission in the KFUPM campus can be reduced by as much as 40,199 tons carbon dioxide equivalent.

The PV application on building roof especially from economic perspective is an area which has not been addressed thus far. Khan et al. (2017) studied the power generation potential for PV application on residential buildings in KSA. Asif (2016) also investigated power output potential of PV system in different types of buildings. Dehwas et al. (2018) adopted a detailed approach to determine utilizability of PV on residential building roofs. None of these studies have covered the economics of PV systems. This study attempts to address the gap and contribute to the scholarship on the subject. It targets to determine the power output from different types of building in an urban environment by taking into account building roof conditions. It also provides detailed economic assessment of PV systems. Subsequent environmental savings are also calculated.

The purpose of this paper is to evaluate the expected cost of a large-sized photovoltaic (PV) system (= 1 MW) in reaching grid parity, not taking into account any type of government incentives (now quite uncommon in industrialized countries). A PV system located in Southern Italy will be the subject of this assessment.

The paper presents the case of a 1 MW ground-mounted PV system. The data regarding solar radiation on the surface of the modules and the relative solar diagrams were simulated and reported using PVSYST® 5.21 software. To evaluate the profitability and solvency of the project, a number of factors were taken into consideration: profitability indicators of net present value and internal rate of return, the debt service coverage indicators of debt service cover ratio and loan life cover ratio and their mean annual values (annual debt service cover ratio and annual loan life cover ratio, respectively). A sensitivity analysis with respect to the most critical element (weighted average cost of capital) gave strength to the results.

The achievement of grid parity for 200 kW PV systems is happening globally in areas with higher irradiation, but it clearly refers to residential utilities and is not applicable to large systems. The case study considers a power plant (= 1 MW) to assess the total cost that it would need to have to be economically advantageous.

This is an assessment made using a case which, given an average irradiance value in the area and the energy produced, can be used in all countries lying in the temperate zone. For other areas, a scaling coefficient would be needed.

The paper is useful for understanding the order of cost, which must catch up to PV technology to make investments in power plants profitable in the absence of government incentives. It is also helpful for those who make government policies so that these may propose possible incentives commensurate with the actual difference between the value of the technology and the value of the investment. The study is also useful for a possible comparison with a system sharing the same characteristics (size, energy production) for off-grid use and customers.

The study can be a valuable support for government policies to incentivate PV systems that contribute to a reduction of greenhouse gases and that help contain climate change. The case study represents a real case taken directly from a real project. This case study and its sustainable features have not been previously presented in a scientific journal.

Photovoltaic (PV) systems are experiencing exponential growth due to environmental concerns, unlimited and ubiquitous solar energy, and starting-to-make-sense panel costs. Alongside designing more efficient solar panels, installing solar trackers and special circuitry for optimizing power delivery to the load according to a maximum power point tracking (MPPT) algorithm are other ways of increasing efficiency. However, it is critical for any efficiency increase to account for the power consumption of any amendments. Therefore, this paper aims to propose a novel tracker while using MPPT to boost the PV system's actual efficiency accounting for the involved costs.

The proposition is an experimental pneumatic dual-axis solar tracker using light-dependent resistor (LDR) sensors. Due to its embedded energy storage, the pneumatic tracker offers a low duty-cycle operation leading to tracking energy conservation, fewer maintenance needs and scalability potential. While MPPT assures maximum load power delivery, the solar PV's actual delivered power is calculated for the first time, accounting for the solar tracking and MPPT power costs.

The experiments' results show an increase of 37.6% in total and 35.3% in actual power production for the proposed solar tracking system compared to the fixed panel system, with an MPPT efficiency of 90%. Thus, the pneumatic tracking system offers low tracking-energy consumption and good actual power efficiency. Also, the newly proposed pneumatic stimulant can significantly simplify the tracking mechanism and benefit from several advantages that come along with it.

To the best of the authors’ knowledge, this work proposes, for the first time, a single-motor pneumatic dual-axis tracker with less implementation cost, less frequent operation switching and scalability potential, to be developed in future works. Also, the pneumatic proposal delivers high actual power efficiency for the first time to be addressed.

This study aims to provide a new method for precisely sizing photovoltaic (PV) arrays for standalone, direct pumping PV Water Pumping (PVWP) systems for irrigation purposes.

The method uses historical weather data and considers daily variability in regional temperatures and rainfall, crop evapotranspiration rates and seasonality effects, all within a nonparametric bootstrapping approach to synthetically generate daily rainfall and crop irrigation needs. These needs define the required daily supply of pumped water to achieve a user-specified level of reliability, which provides the input to an intuitive approach for PV array sizing. An economic comparison of the costs for the PVWP versus a comparably powered diesel generator system is provided.

Pumping 22.8646 m³/day of water would meet the pasture crop irrigation needs on a one-acre (4046.78 m²) tract of land in South Florida, with 99.9% reliability. Given the specified assumptions, an 8.4834 m² PV array, having a peak power of 1.1877 (kW), could provide the 1.2347 (kWh/day) of hydraulic energy needed to supply this volume over a total head of 20 meters. The PVWP system is the low-cost option when diesel prices are above $0.90/liter and total installed PV array costs are fixed at $2.00/Watt peak power or total installed PV array costs are below $1.50/Watt peak power and diesel prices are fixed at $0.65/liter.

Because the approach is not dependent on the shapes of the sampling distributions for regional climate factors and can be adapted to consider different types of crops, it is highly portable and applicable for precisely determining array sizes for standalone, direct pumping PVWP systems for irrigating diverse crop types in diverse regions.

The application of hybrid renewable energy system (HRES) can mitigate inadequate access to clean, stable and sustainable energy among households in sub-Saharan Africa (SSA). Available studies on HRES seem to concentrate only on its techno-economic and environmental viability. In so doing, these studies do not seem to underline the likely challenges that follow the acquisition of HRES by especially low-income households. The ensuing reality is, of course, a limitation in the use of HRES in homes with low incomes. It is therefore imperative to analyze how a household with low income can afford this kind of energy system. The purpose of this study, therefore, lies in presenting a techno-economic, environmental and affordability analysis of how HRES is acquired.

To arrive at a grounded analysis, a typical household in SSA is used as an example. The analysis focused on the pattern of energy use, and this is obtained by visiting an active site to evaluate the comprehensive load profile. In the course of analysis, an optimal techno-economic design and sizing of a hybrid PV, wind and battery were undertaken. Additionally, an acquisition analysis was done based on loan amortization.

The interesting result is that a combination of the photovoltaic-gasoline-battery system is the most cost-effective energy system with a net present cost of $2,682. The system combination can lead to an emission reduction of approximately 98.3 per cent, compared to the use of gasoline generating sets, common mostly in SSA. If an amortized loan is used to purchase the energy system, and the payment plan is varied such that the frequency of payments is made quarterly, annually, semi-annually, bi-monthly, semi-monthly and bi-weekly, it will be observed that low-income household can conveniently acquire a HRES.

The result presented a framework by which a low-income household can purchase and install HRES. To facilitate this, it is recommended that low-income households should be given interest-friendly loans, so as to enhance the acquisition of HRES.

The purpose of this study was to design a renovation plan for a university campus building (Department of Electrical and Computer Engineering) with the aim to achieve nearly zero energy performance, ensuring a low specific demand (lower than 44 kWh/m²) and a high level of on-site renewable generation (equivalent to more than 20 per cent of the energy demand).

The baseline demand was characterized based on energy audits, on smart metering data and on the existing building management system data, showing a recent reduction of the electricity demand owing to some implemented measures. The renovation plan was then designed with two main measures, the total replacement of the actual lighting by LEDs and the installation of a photovoltaic system (PV) with 78.8 kWp coupled with an energy storage system with 100 kWh of lithium-ion batteries.

The designed renovation achieved energy savings of 20 per cent, with 27.5 per cent of the consumed energy supplied by the PV system. This will ensure a reduction of the specific energy of the building to only 30 kWh/m², with 42.4 per cent savings on the net-energy demand.

The designed renovation proves that it is possible to achieve nearly zero energy goals with cost-effective solutions, presenting the lighting renovation and the solar PV generation system a payback of 2.3 and 6.9 years, respectively.

This study innovated by defining ambitious goals to achieve nearly zero energy levels and presenting a design based on a comprehensive lighting retrofit and PV generation, whereas other studies are mostly based on envelope refurbishment and behaviour changes.

In October 2011 the Government brought in measures to reduce the revenue provided by the Feed in Tariff (FIT) system. This change came under a lot of opposition due to the potential affects that it would have upon the industry. The purpose of this paper is to explore the potential benefits of the FIT and the impact that the Governments Comprehensive Spending Review had upon the industry and its uptake by the householders.

For the study and to calculate the benefits of the FIT, a predictive modelling tool was built that could calculate the potential income and savings for a household. A photovoltaic (PV) installation was then monitored for over a year and the results of the predictive modelling tool were compared to actual results produced from the system to show how accurate the modelling tool was. The impacts of the Governments comprehensive spending review and the potential impacts in the industry were then calculated and discussed.

The FIT is still a good incentive for people investing in PV. However, the reduction in the FIT may impact the “Rent a Roof” system and this in turn will impact most heavily on lower income families. The research also concluded that the changes in the political agenda have had a major impact on the FIT for both the industry and the community. Thus, the solar FITs will continue to be an attractive incentive in place to pay for heating through renewable means and thus ensuring reducing the own carbon footprint. Concomitantly, well-developed ownership schemes need to be put in place.

The reduction in the FIT was the right move by the Government as it should prevent the increase in energy bill prices which will affect the people without PV at this point in time. It also has been set so that it is still generous enough to encourage the industry and stimulate installation as there is still profit but not in a way that should put people off. The UK may just have to take time to realise that the FITs are still a good deal after the very generous tariff that preceded them.