Yazarlar
- Ozden, Talat(16)
- Akinoglu, Bulent G.(15)
- Sezer, İsmet(11)
- Basoglu, Mustafa Engin(9)
- Özden, Talat(8)
- Akpinar, Adem(7)
- Terhan, Meryem(7)
- Başoğlu, Mustafa Engin(6)
- Cakmak, Recep(6)
- Erol, Ismail(6)
- Peker, Iskender(6)
- Turan, Rasit(6)
- Akpinar, A.(5)
- Ar, Ilker Murat(5)
- Kömürcü, Murat Ihsan(5)
- Sezer, Ismet(5)
- Altas, Ismail H.(4)
- Altuner, Elif Esra(4)
- Benli, Tolga(4)
- Bozbeyoglu, Pinar(4)
- Kaygusuz, K.(4)
- Tunç, Merve Tuğçe(4)
- Akyol, Mehmet(3)
- Altan, Aytaç(3)
- Barut, Abdulkadir(3)
- Bilgin, Atilla(3)
- Genc, Omer(3)
- Kankal, Murat(3)
- Kaygusuz, Abdullah(3)
- Kaygusuz, Kamil(3)
- Ozden, T.(3)
- Pilatin, Abdulmuttalip(3)
- Saribiyik, Oguz Yunus(3)
- Searcy, Cory(3)
- Timurkutluk, Bora(3)
- Toros, Serkan(3)
- Turan, İsmet(3)
- Yanarates, Cagfer(3)
- Yanarateş, Cağfer(3)
- Çakmak, Recep(3)
Yayınlar
- MakaleAçık Erişim2024OUTDOOR DEGRADATION ANALYSES OF SIX DIFFERENT AGED PHOTOVOLTAIC MODULE TECHNOLOGIES UNDER THE ARID-STEPPE CLIMATE CONDITION
Cantürk, Zeynep; Özden, Talat; Akinoglu, Bulent G.
Outdoor tests of photovoltaics module are crucial both for marketing and for research and technological developments. The electric generation performance and their degradation rates and lifetime are also related to different climatic conditions of the regions. In this work, the outdoor tests are carried out for six different photovoltaic (PV) modules under Arid-steppe Climate condition of Ankara, Türkiye. Their degradation rates are calculated by using linear regression (LR) and year on year (YOY) methods. The comparison between LR and YOY are carried out and with the other performed studies of different regions of world. In addition, it is investigated that how effective the climatic conditions on daily degradation rates. The results obtained are as follows: Mono-Si and Hetero-junction Silicon (HIT) cell modules degradation rates of 0.71/1.56 %/year and 0.84 %/year are respectively obtained by LR method and 0.57/0.90 %/year and 0.85%/year are respectively by YOY method. The degradation rates for Cupper Indium Selenide (CIS), Cupper Indium Gallium Selenide (CIGS) and microcrystalline Silicon/Amorphous Silicon (µc-Si/a-Si) modules have 1.73/1.49 %/year, 11.55/9.52 %/year and 1.48 %/year for LR method and 1.28/1.12 %/year, 9.94/9.53 %/year and 0.99 %/year for YOY method are obtained respectively. It is also obtained for the Polycrystalline Silicon Modules as 1.20/1.86 %/year degradation rates by LR method and 0.79/1.88 %/year degradation rates by YOY method.
- MakaleAçık Erişim2024Enhanced Hysteresis Droop Control for Equivalent Load Sharing in Parallel PWM DC-DC Converters: Optimized Slew Rate by Resonant Filtering
Yanarates, Cagfer; Altan, Aytac
In this study, enhanced hysteresis droop control for equivalent and fast load sharing in parallel PWM DC-DC converters is presented. The basis behind the work encompasses power system stability, reliability, efficiency, reduction of losses and decrease in the operational cost. In this context, phase management, which constitutes the biggest problem, and the resulting factors such as ripple cancellation, thermal stress, transient response behavior and complexity, is aimed to manage with the proposed control scheme. Performance evaluation of the proposed system is based on sensitivity analysis against possible disturbance and noise, and comparative analysis with PI controller against uncertainty and parameter variations using mathematical modeling and simulation techniques. The results show that the proposed controller has improved performance in both noise attenuation and disturbance rejection at typical switching frequencies of DC-DC converters ranging from 100 kHz to a few MHz. Additionally, applying the proposed control technique considering 10% parameter variations led to the largest difference being recorded at 4% while this difference was 18.68% in conventional PI control. According to the findings of the simulation, the proposed control scheme reduces the settling time by a factor of 4.89, whereas it takes 775.862 μs seconds with the PI controller. Furthermore, with the suggested controller, the overshoot - which was 36.09% with the PI controller - is reduced to just 1%.
- MakaleAçık Erişim2024Effect of thickness and melting temperature of phase change material integrated into exterior wall on building energy performance and CO2 emission reduction; [Dış duvara entegre edilen faz değiştiren malzemenin kalınlığı ve erime sıcaklığının bina enerji performansı ve CO2 emisyon azalımına etkisi]
İlgar, Gamze; Terhan, Meryem
In the study, the effect of phase change materials integrated into the building's external wall has been investigated in terms of material type, thickness, and melting temperature of phase change material on the building energy performance for İzmir Province. A villa residential project has been modelled in 3D using DesignBuilder energy simulation software and two different external wall configurations have been designed by changing the position, thickness and melting temperature of the PCMs into the wall. The amount of CO2 emission reductions that PCMs will provide according to the fuel type of the building's heating system has been calculated. Using PCMs in the external wall not only provides high heating and cooling energy savings but also increases thermal comfort indoors by reducing temperature fluctuations. The PCM melting temperature of 23℃ performs quite well compared to other temperatures in both cooling energy and heating energy demand reduction. By increasing the triple thickness of the PCM, 18.81% in heating energy and 22.85% in cooling energy savings can be achieved. Depending on the external wall and phase change material types, different thicknesses and melting temperatures of PCM, annual total energy saving of the phase-change material is calculated between 10,349.50-83,345.98 kJ/m2.year and the annual CO2 emission reduction according to fuel types has been found as 0.672-14.284 kgCO2/m2.year.
- MakaleYalnız künye2024Waste Heat and Mass Recovery from Boiler Exhaust Gases in a New Generation District Heating System: Energy and Exergy Analysis
Terhan, Meryem
The study performs energy and exergy analyses for each component such as boilers, buildings, distribution networks and heat exchangers of a new generation district heating system. Energy and exergy efficiencies are compared for all system components, and energy and exergy losses are presented using Sankey and Grassman diagrams. Three flue gas condensers with finned bundles are designed for different capacities of boilers that intend to recover water and heat from the waste flue gas in the district heating system due to high flue gas energy losses. Colburn-Hougen and one-dimensional finite difference methods are used to design the flue gas condensers with the MATLAB program. The exergy analysis showed that the exergy input to the system is lost by 4.52% from the distribution networks, 4.15% from all buildings and 2.18% from the flue gas. In the system, the energy and exergy efficiencies of the boilers are calculated to be 87.23% and 17.32%, respectively, and the heat loss from the flue gas is found to be 12%. The design results show that the values of mass convection coefficient (km) for all flue gas condensers decrease from 0.0706 at the inlet condensation zone to 0.0354 towards the outlet. The total condensation rate and condensation efficiency are found to be 86 kg/h and 60%, respectively, for the 2500 kW boiler.
- MakaleAçık Erişim2024Exploring the enablers for building resilience in solar photovoltaic Energy supply chains
Erol, Ismail; Peker, Iskender; Benli, Tolga; Ar, Ilker Murat; Searcy, Cory
A solar photovoltaic energy supply chain (SPvESC) is a global network with several linkages, including mineral and metal mining, material processing, and module and panel manufacturing. Due to the wide range of uncertainties and the unfavorable environmental effects associated with current linear business models, this global network is vulnerable to disruptions. Strengthening the resilience of SPvESCs is crucial for addressing any disturbances. This requires identifying the key enablers of resilience in SPvESCs, an area that has been understudied in the existing literature. An enabler is an aspect that facilitates the achievement of a goal by another aspect. This research contributes to the existing literature by systematically investigating the enablers for SPvESCs to achieve resilience. Thus, the objective of this analysis is to identify enablers that have the potential to enhance the resilience of SPvESCs in Türkiye. This was done by applying the Nominal Group Technique (NGT) in conjunction with a review of the current literature. Neutrosophic (N)-DEMATEL was then utilized to determine the relationships between the identified enablers. Finally, the results were validated using N-DELPHI. The results revealed that sensing and seizing new business models, adaptability to changes in novel energy generation and information technologies, and business contingency plans for natural and man-made disasters were the most influential enablers. The findings provide implications for practitioners, policymakers, and researchers to help ensure improved resilience in SPvESCs.
- MakaleAçık Erişim2024Economic Evaluation of Thermal and Mechanical Activation Energies in Plaster Production
Şener, Muhammed; Uysal, Turan; Erdemoğlu, Murat
Plaster is among the most needed raw materials in the world. In this study, thermal activation provided by calcination and mechanical activation methods provided by intensive milling in the plaster production process were evaluated in terms of activation energy. In this context, the energies of laboratory-scale thermal and mechanical activation processes were calculated and these activation methods were evaluated economically and the ideal activation methods were determined. Although the mechanical activation method creates additional investment and operating costs, it reduces the calcination temperature by 13 °C, thus provides lower energy costs. Addition of a mechanical activator mill before thermal activation in plaster production as a more economical and more environmentally friendly method was proposed.
- MakaleAçık Erişim2024Enhancing the performance of parabolic trough solar collectors: Cost-effective innovative designs for sustainable energy harvesting
Karaağaç, Mehmet Onur; Akıncı, Burak; Ergün, Alper
This study aims to improve the performance and stability of parabolic trough solar collectors (PTSC), especially those with heat storage capacity. Three different receiver tube designs have been meticulously developed to achieve this goal. As a result of the research, the Black surface (BS) -PTSC and PTSC- Paraffin wax (PW) systems achieved 26.5% and 56.8% more thermal energy flow, respectively, compared to the conventional PTSC. In addition, while the average thermal efficiencies of the PTSC, BS-PTSC, and PTSC-PW systems were found to be 11.2%, 14.1%, and 16.9%, respectively, the average exergy efficiencies of the PTSC, BS-PTSC, and PTSC-PW were 1.4%, 1.9%, and 2.3%. Painting the black copper pipe and filling the receiver tube with paraffin wax PCM increased thermal and exergy efficiency. Besides, comparing the temperature differences based on the PTSC system, it was found that BS-PTSC and PTSC-PW systems have 12.3% and 16.4% higher tank temperatures, respectively. The findings of this research have demonstrated the potential of parabolic trough solar collectors equipped with heat storage. It has also increased the sustainability index in terms of sustainability and reduced CO2 emissions into the atmosphere. Furthermore, it has been shown that these simple and inexpensive designs, without significant modifications to the system, can achieve high thermal performance without unnecessary expensive components.
- MakaleAçık Erişim2024A robust chaos-inspired artificial intelligence model for dealing with nonlinear dynamics in wind speed forecasting
Barış, Caner; Yanarateş, Cağfer; Altan, Aytaç
The global impacts of climate change have become increasingly pronounced in recent years due to the rise in greenhouse gas emissions from fossil fuels. This trend threatens water resources, ecological balance, and could lead to desertification and drought. To address these challenges, reducing fossil fuel consumption and embracing renewable energy sources is crucial. Among these, wind energy stands out as a clean and renewable source garnering more attention each day. However, the variable and unpredictable nature of wind speed presents a challenge to integrating wind energy into the electricity grid. Accurate wind speed forecasting is essential to overcome these obstacles and optimize wind energy usage. This study focuses on developing a robust wind speed forecasting model capable of handling non-linear dynamics to minimize losses and improve wind energy efficiency. Wind speed data from the Bandırma meteorological station in the Marmara region of Turkey, known for its wind energy potential, was decomposed into intrinsic mode functions (IMFs) using robust empirical mode decomposition (REMD). The extracted IMFs were then fed into a long short-term memory (LSTM) architecture whose parameters were estimated using the African vultures optimization (AVO) algorithm based on tent chaotic mapping. This approach aimed to build a highly accurate wind speed forecasting model. The performance of the proposed optimization algorithm in improving the model parameters was compared with that of the chaotic particle swarm optimization (CPSO) algorithm. Finally, the study highlights the potential of utilizing advanced optimization techniques and deep learning models to improve wind speed forecasting, ultimately contributing to more efficient and sustainable wind energy generation. This robust hybrid model represents a significant step forward in wind energy research and its practical applications.
- MakaleAçık Erişim2024GIS-based multi-influencing factor (MIF) application for optimal site selection of solar photovoltaic power plant in Nashik, India
Rane, Nitin Liladhar; Günen, Mehmet Akif; Mallick, Suraj Kumar; Rane, Jayesh; Pande, Chaitanya B.; Giduturi, Monica; Bhutto, Javed Khan; Yadav, Krishna Kumar; Tolche, Abebe Debele; Alreshidi, Maha Awjan
The significant natural energy sources for reducing the global usage of fossil fuels are renewable energy (RE) sources. Solar energy is a crucial and reliable RE source. Site selection for solar photovoltaic (PV) farms is a crucial issue in terms of spatial planning and RE policies. This study adopts a Geographic Information System (GIS)-based Multi-Influencing Factor (MIF) technique to enhance the precision of identifying and delineating optimal locations for solar PV farms. The choice of GIS and MIF is motivated by their ability to integrate diverse influencing factors, facilitating a holistic analysis of spatial data. The selected influencing factors include solar radiation, wind speed, Land Surface Temperature (LST), relative humidity, vegetation, elevation, land use, Euclidean distance from roads, and aspect. The optimal sites of solar PV power plant delineated revealed that 'very low' suitability of site covering 4.866% of the study area, 'low' suitability of site 13.190%, 'moderate' suitability of site 31.640%, 'good' suitability of site 32.347%, and 'very good' suitability of site for solar PV power plant encompassing 17.957% of the study area. The sensitivity analysis results show that the solar radiation, relative humidity, and elevation are the most effective on the accuracy of the prediction. The validation of the results shows the accuracy of solar PV power plant prediction using MIF technique in the study area was 81.80%. The integration of GIS and MIF not only enhances the accuracy of site suitability assessment but also provides a practical implementation strategy. This research offers valuable insights for renewable energy policymakers, urban planners, and other stakeholders seeking to identify and develop optimal locations for solar energy power farms in their respective regions.
- MakaleAçık Erişim2024Does structural change matter for sustainable development in newly industrialized countries? Fresh evidence from a new sustainability indicator
Artan, Seyfettin; Erdogan, Sinan; Recepoglu, Muersit; Çakir, Suemeyra cay; Hayaloglu, Pinar; Çakir, Mehmet Ali
The economic gap between developed and developing economies has been diminishing due to the recent rapid economic growth performance of developing economies. While achieving this swift growth level, developing economies have structurally transformed their economies. However, the impact of this structural change on environmental sustainability remains unclear. Therefore, this study focuses on the impacts of structural change, energy structure, and economic growth on the load capacity factor, a comprehensive sustainability indicator, in newly industrialized countries during 2000-2020. To this end, second-generation panel data techniques, which account for cross-sectional dependence and heterogeneity, are used to provide more robust and reliable estimates. The results show that economic growth, structural change, and fossil energy utilization decrease the load capacity factor while renewable energy utilization increases it. These findings underscore the need for energy efficiency and resource-conscious policies that align with environmental sustainability while promoting economic growth, highlighting their crucial role in the future of sustainable development.
- Derleme MakaleAçık Erişim2023Dizel Motorlarda Dimetil Eter Kullanımının Partikül Madde Emisyonlarına Etkileri Üzerine Bir Derleme
Sezer, İsmet
Bu çalışma, dizel motorlarda dimetil eter (DME)’in saf veya yakıt katkısı olarak kullanımı üzerine yapılmış çeşitli çalışmaların sonuçlarından yararlanılarak derlenmiştir. Dizel motorlarda zararlı egzoz emisyonlarını azaltmanın birkaç yöntemi vardır. Bunlardan ilki motor tasarımında ve yakıt enjeksiyon sisteminde modifikasyonlar yaparak yanmanın iyileştirilmesidir, ancak bu pahalı ve zaman alıcı bir yöntemdir. İkinci yöntem ise katalitik konvertör ve partikül fitresi gibi donanımlar kullanmaktır, ancak bu donanımlar motor performansını olumsuz yönde etkiler. Hem egzoz emisyonlarını azaltmak hem de motor performansını artırmak için uygulanan son yöntem çeşitli alternatif yakıtların veya yakıt katkılarının kullanılmasıdır. Dizel motorlardaki en önemli emisyonlar azot oksitler (NOx) ve partikül madde (PM) emisyonlarıdır. Çoğu araştırmacı emisyonları azaltmanın en iyi yolunun doğalgaz, biyogaz, biyodizel gibi alternatif yakıtların veya konvansiyonel veya alternatif yakıtlarla birlikte çeşitli yakıt katkılarının kullanılması olduğunu bildirmektedir. Bu nedenle, alternatif yakıtlar ve yakıt katkıları üzerine yapılan çalışmaların sonuçlarının birlikte değerlendirilmesi pratik uygulamalar için oldukça önemlidir. Bu çalışma, dimetil eterin dizel motorlarda yakıt veya yakıt katkısı olarak kullanılmasının PM emisyonları üzerindeki etkilerinin incelenmesine odaklanmıştır. Yapılan derleme çalışması sonucunda; DME saf olarak kullanıldığında yüksek oksijen içeriği, kimyasal yapısında direkt bağlı karbon bulunmaması, hızlı buharlaşma, yüksek setan sayısı ve düşük tutuşma sıcaklığı gibi özellikleri sayesinde sıfıra yakın PM emisyonu elde edilmesini sağladığı belirlenmiştir. Saf DME’nin dizel yakıtına kıyasla PM emisyonunu %13–228 ve biyodizel yakıtına kıyasla %88.6–227.6 azalttığı tespit edilmiştir. Ayrıca, farklı oranlarda DME içeren dizel–DME karışımlarının dizel yakıtına kıyasla PM emisyonunu %4.7–509 azalttığı ve farklı oranlarda DME içeren biyodizel–DME karışımlarının PM emisyonunu biyodizel yakıtına kıyasla %38.2 azalttığı tespit edilmiştir. Diğer taraftan, LPG–DME karışımının dizel yakıtına kıyasla PM emisyonunu %269–493 azalttığı ve farklı oranlarda DME içeren DME–NH3 karışımlarının saf DME’ye kıyasla PM emisyonunu %40.7–96.7 artırdığı tespit edilmiştir. Öte yandan, egzoz gazı resirkülasyonu (EGR) oranının %10–50 aralığında değiştirilmesinin PM emisyonunu %13.1–48.4 artırdığı tespit edilmiştir.
- Derleme MakaleAçık Erişim2023A review study on the use of dimethyl ether in diesel engines: effects on CO2 emissions
Sezer, İsmet
Emissions from vehicles and other fuel combustion systems can alter the composition of the atmosphere and augment its capacity to absorb heat. These gases, which are effective at trapping heat, are known as greenhouse gases and include all gases found in vehicle emissions. Reducing the emissions of carbon dioxide (CO2) has become an urgent necessity around the world, and many countries have imposed limits on their CO2 output. Using biofuels in automotive engines is an effective way of reducing greenhouse gas emissions. The CO2 emissions emitted from the combustion of biofuels are absorbed as trees and plants grow. Biofuels can be used either as pure fuels or blended with conventional fuels. Most research has declared that the most effective way to reduce greenhouse emissions is the use of various biofuels. Therefore, it is essential to assess the outcomes of research regarding alternate fuels or fuel additives to determine their proper utilization. Using of diesel engines can also help reduce CO2 emissions as they emit less CO2 emissions than gasoline engines. This review study investigates the effects the using of dimethyl ether on CO2 emissions in diesel engines. The results showed that CO2 emissions decrease when using the pure DME and DME blends with diesel and LPG fuels due to the oxygen content and the lower carbon to hydrogen ratio of DME. The decrements in CO2 emissions for pure DME, diesel–DME blends and LPG–DME blend are about 5.2–18.3%, 3–41.6% and 10.6–16.4%, respectively.
- MakaleYalnız künye2023Investigation of used PCM-integrated into building exterior walls for energy savings and optimization of PCM melting temperatures
Terhan, Meryem; Ilgar, Gamze
In the study, the effects on the building's thermal energy performance of using two different phase change materials (PCMs) integrated into the exterior walls at various thicknesses and melting temperatures have been investigated. Four exterior wall types have been designed by changing the position of PCM integrated into the exterior wall for the purpose to decrease heating and cooling energy demand. For each wall type, three different thicknesses (layers) have been studied and energy savings that PCM provided by decreasing the heating and cooling energy demands have been calculated on a monthly and annual basis. According to the energy simulation analyses, the configuration provided the highest heating energy savings (21.32 %) on an annual basis is the three-layer BioPCM27 integrated exterior wall with a melting temperature of 21 °C. The monthly optimum melting temperatures of PCMs have been determined based on the charge and discharge processes of PCM integrated into the exterior walls by evaluating the results of hourly energy simulation analysis. The annual average optimum melting temperature varies between 18 and 19 °C, depending on the exterior wall and material types. The three-layer (3L) InfiniteRPCM21C configuration (Type 3) has the best thermal energy performance among all exterior wall types, with 24.45 % total energy savings in the cooling season and 14.76 % in the heating season.
- BildiriYalnız künye2023Current Sources and Actual PV Modules based Photovoltaic (PV) Emulator for Testing MPPT Algorithms and PV Inverters
Zhou, Zhongfu; Wang, Yidong; Yanarates, Cagfer; MacAulay, John
PV array emulator has been widely used for testing PV inverters and their control algorithms such as maximum power point tracking (MPPT) algorithms. Various power electronics converter-based PV emulators have been presented in many research papers. This paper presents a PV emulator that is based on indoor solar panels (without solar irradiance) and external current source (dc power supply). The external current source is used to emulate the photo current that is usually generated by solar panel under sunlight. The advantages of the proposed PV emulator are that it can generate similar electrical characteristics of actual PV panel without sunlight, it is suitable for testing PV inverters and MPPT algorithms in indoor conditions where the sunlight is usually very weak. In addition, a PV array emulator that can emulate electrical performance under partial shading conditions was constructed by using two solar panels and two current sources. Test results show that the proposed PV emulator provides a similar performance of real PV array under real sun light. It provides a low-cost solution for testing PV inverters and control algorithms inside a laboratory environment.
- MakaleAçık Erişim2023Energy, exergy analysis and optimization of insulation thickness on buildings in a low-temperature district heating system
Terhan, Meryem; Abak, Sena Saliha
In the study, energy and exergy analysis of the buildings on a campus in Turkey are conducted by using actual operating data and taking measurements in the district heating system as a case study. The energy and exergy demands, losses that stem from all buildings are calculated according to average daily outdoor temperature data. Due to the high heat losses in the buildings, determining the optimal insulation thickness for the exterior wall should be investigated. Therefore, optimal insulation thicknesses, energy savings, fuel consumptions and payback periods of the insulation material on the exterior wall of the building are examined by using Life Cycle Assessment and P1–P2 method for natural gas. Optimal insulation thicknesses are calculated for different insulation materials such as XPS, glass wool, rock wool and EPS for the climatic regions (HDD=800–4250°C days). According to average exergy losses from the building components per unit area, the average total exergy loss is calculated as 2.39×10-2 kW/m2.year and 1.42×10-3 kW/m2 (5.92%) of this loss stems from the exterior walls, 1.93×10-3 kW/m2 (8.07%) from the floors, 7.37×10-4 kW/m2 (3.08%) from the roofs, 1.58×10-2 kW/m2 (65.99%) from the windows and doors, 4.04×10-3 kW/m2 (16.92%) from the ventilation with infiltration. Energy requirement values of the building are found between 2.68–25.70 kWh/m3 towards from the warmest to the coldest climatic region for the uninsulated wall. In the un-insulated state, fuel consumption varies between 1.93-18.48 m3/m2 from the warmest to the coldest region. The optimal insulation thickness values of the building’s exterior wall are calculated as between 2.3–10.0 cm according to different climatic regions. In-state of exterior wall insulation of 3 cm, fuel consumption decreases by 46.63%–53.46% compared to different insulation materials and climatic regions compared to the un-insulated state
- MakaleYalnız künye2023SPAN: An open-source plugin for photovoltaic potential estimation of individual roof segments using point cloud data
Özdemir, Samed; Yavuzdoğan, Ahmet; Bilgilioğlu, Burhan Baha; Akbulut, Zeynep
Decentralized solar PhotoVoltaic (PV) is one of the most promising energy sources for cities and individuals pursuing energy self-sufficiency. Especially, the already available rooftop surfaces are a major contributor to push for rooftop mounted PV systems. However, accurate PV potential estimation of individual buildings is still a challenging task since many parameters must be considered such as meteorological factors, panel technology, geographical location, available roof surface area, surface azimuth and tilt angle. In this study, we created an efficient approach that can be used for roof surface's PV potential estimation based on point cloud data and capable of processing various scales from single building to city scale. In the proposed approach, each roof surface's features were utilized for PV potential estimation by employing the PVGIS database. PV potential estimation was carried out on daily, monthly, and annual periods to provide a better estimation. Also, we developed a flexible and easy to use open-source plugin based on the QGIS software for rooftop mounted PV potential estimation capable of estimating every roof surface's PV potential. The method was tested on 80 buildings selected from ROOFN3D dataset. The proposed approach achieved an overall accuracy of 84% and an F1 score of 0.92.
- BildiriYalnız künye2023Analysis Of The Performance Of The Distributed Maximum Power Point Tracking In Building Integrated Photovoltaic Systems
Basoglu, Mustafa Engin; Aiordachioaie, D.
Building-integrated/applied photovoltaic (PV) systems have been widespread recently in terms of electrical energy generation in buildings. These systems are applications with much lower power than land type large-scale systems, addressing the area/building where they are installed rather than centralized production. In this framework, maximum power point (MPP) tracking (MPPT) approaches at module level and sub-module level, balcony railing, Carport or solar tile etc. will be investigated in terms of building integrated PV systems (BIPV). Solar panels act as a building material, insulation material and energy generator in BIPV applications. In building-applied (BAPV) examples, the solar panel is mounted on the building. However, there is no difference between BIPV and BAPV in terms of electrical model. A unique method will be developed for MPPT at module level and sub-module level for such applications. Depending on the power processing strategy in the optimizer power stage, amplifier, synchronous reducer or bidirectional differential power processing topologies will be examined and the most suitable power converter for the module and sub-module level will be determined. Technically, comparisons of the performances of MPPT strategies were made in the MATLAB/Simulink program at the central, module level or sub-module level, and it was shown that the power that can be obtained from the PV module or sub-module increases with the MPPT at the module and sub-module level.
- MakaleAçık Erişim2023Performance analysis of digitally controlled nonlinear systems considering time delay issues
Yanarateş, Cağfer; Okur, Serkan; Altan, Aytaç
In this paper, a comprehensive investigation into discretization, effective sample time selection considering delays in the system, and time and frequency domain analysis of a DC-DC buck converter, which plays a vital role in photovoltaic (PV) systems, is conducted to enhance the understanding of their dynamic behavior, optimize control algorithms, improve system efficiency, and ensure reliable power conversion in photovoltaic applications. To effectively address the non-linear behavior and enhance digital control of a buck converter by selecting the best sample time, several approaches can be employed. These include accurate modeling and identification of non-linear elements, development of advanced control algorithms that account for non-linearities, implementation of adaptive control techniques, and utilization of feedback mechanisms to compensate for deviations from linearity. By considering and mitigating the non-linear behavior, digital control systems can achieve improved accuracy, stability, and transient behavior in regulating the buck converter's output waveforms (voltage or current). The results of the study demonstrated that the trapezoidal integration method which is also known as bilinear approximation, or Tustin's approach outperformed other commonly used discretization methods, such as first-order hold (FOH), zero-order hold (ZOH), impulse response matching (impulse invariant), and matched pole-zero (MPZ) technique, in dual-domain (both time and frequency) analysis. The key finding highlighting the superiority of the bilinear approximation was its ability to achieve the closest match in the frequency domain bridging the continuous-time and discrete systems. This finding emphasizes the significance of the bilinear approach in preserving the frequency characteristics of the original continuous-time system during discretization. By employing this method, the discrete system closely approximated the behavior of its continuous-time counterpart, ensuring accurate frequency-domain representation.
- MakaleAçık Erişim2023Investigating the EKC hypothesis with nanotechnology, renewable energy consumption, economic growth and ecological footprint in G7 countries: panel data analyses with structural breaks
Aydin, Mucahit; Koc, Pınar; Sahpaz, Kadriye Izgi
This study investigates the relationship between nanotechnological innovations, renewable energy consumption, economic growth, and ecological footprint for G7 countries within the framework of the Environmental Kuznets Curve (EKC) hypothesis. The study employs panel cointegration tests with structural breaks from 1990–2018. Nanotechnology is expected to reduce environmental degradation by increasing renewable energy consumption and energy saving. In this context, nanotechnological innovations are an essential tool for sustainable development. However, the literature also emphasizes that nanoparticle emissions from nanotechnology can negatively impact human and environmental health in the long term, and these need to be analyzed. In this context, this study is the first to empirically examine the relationship between nanotechnological innovations, renewable energy consumption, economic growth, and ecological footprint within the framework of the EKC hypothesis. The outcomes affirm that all variables are integrated with the long term. The results show that the EKC hypothesis is valid only in the USA. Nanotechnological innovations have a reducing effect on environmental degradation in the USA, whereas; they have an increasing impact on environmental degradation in Italy and the United Kingdom. Renewable energy consumption enhances environmental quality in Italy, Japan, the United Kingdom, and the USA. Based on these empirical findings, the government should pioneer to development of new the lowest nanoparticle-emitting nanotechnologies. And that way, it will be possible to encourage energy savings and renewable energy consumption more safely, and the effectiveness of sustainable development policies will increase.
- MakaleAçık Erişim2023Energy and economic assessments of waste heat recovery by designs of economizer, condensing economizer and air preheater; [Ekonomizer, yoğuşmalı ekonomizer ve hava ön ısıtıcı tasarımları ile atık ısı geri kazanımının enerji ve ekonomik değerlendirilmesi]
Terhan, Meryem; Özağdaş, Emre; Omar, Muhammed Arslan
In this study, the waste heat loss of flue gases from the boilers of Kafkas University district heating system has been calculated between 6-8% according to the combustion analysis and the annual cost of this heat loss has been found as $58,658.79. In terms of energy efficiency and the national economy, we think that this lost energy should be recovered as much as possible and fuel and energy savings should be achieved. In the paper, the effects of variants such as air excess coefficient, flue gas temperature, boiler capacity and fuel consumption on the heat recovery from flue gas have been presented in detail. The heat recovery scenarios have been presented for reusing this waste energy for space heating, domestic hot water, and preheating combustion air and the applicability of these scenarios has been investigated in terms of thermodynamics and economics. According to the results of the study, in the second scenario examined to cover the domestic hot water need of the guest house building, the energy savings of the scenario can be provided during 20 years of economic life is $122,820.83, and it has the highest savings income among the scenarios. In addition, it is possible to recover approximately 50% of the flue gas loss with thanks to the scenario. On the other hand, the third scenario of heating the boiler combustion air with waste heat is the easiest and most economical scenario because its payback period is only one year, and there are no extra excavation and pipe costs.
