Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2025Agrivoltaic system design for sugar beets and wheat in central Anatolia
Yalçın, Ömer; Kuzyaka, Duygu; Özden, Talat
Agrivoltaic systems, which integrate photovoltaic (PV) panels with the usage of agricultural land, emerge as a promising strategy by facilitating the simultaneous generation of renewable energy alongside the cultivation of various crops within the same area. This research is centered on the design and implementation of an agrivoltaic system that is specifically customized for the cultivation of wheat and sugar beet in the Central Anatolia Region of Turkey. The primary objective of this research is to optimize the spatial arrangement of the PV panels to achieve a balance between the generation of energy and the productivity of the crops. Through a detailed assessment of shading effects and Photosynthetic Photon Flux Density (PPFD) levels, this investigation will endeavor to unravel the complex interplay between panel configuration and its consequential impacts on both plant growth and energy output. In this investigation, the shading impacts attributed to three distinct configurations—specifically, the conventional solar power plant (SPP), the intermittently arranged panel layout, and the intermittently arranged V-shaped panel configuration—were assessed, and their appropriateness for the cultivation of wheat and sugar beet was evaluated. The V-shaped design, which additionally facilitates rainwater collection, yielded an enhanced PPFD value across the three designated regions beneath the panels.
- 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.
- BildiriYayıncıda açık erişim2022Shading Effect of Transparent Photovoltaic Panels on Crops Underneath Agrivoltaic Systems
Esmaeilzad, Nasim Seyedpour; Dino, Ipek Gursel; Güney, Dilara; Yildirim, Yusuf Ersoy; Turan, Rasit; Özden, Talat; Amaducci, S
Agrivoltaic systems combine soil-grown crops with photovoltaic (PV) panels erected several meters above the ground. Combining solar panels and food crops on the same land can maximize land utilization. Under the PV panels, however, microclimate factors like solar radiation, air temperature, humidity, and soil temperature change. An agrivoltaic system must optimize sunlight sharing between solar panels and crops to maximize food energy production. It has been challenging to improve and analyze the performance of agrivoltaic systems due to the lack of a defined crop-specific parameter. In this work, we present a practical option to partially replace bifacial modules with semi-transparent ones, providing comparable levels of crop protection and greater climate change resilience while generating green energy and increasing land-use efficiency. The agrivoltaic system must be tailored to satisfy the needs of crops. For this purpose, a simulation model was conducted, which examined the impact of module transparency and cell layout based on light availability.
- BildiriAçık Erişim2018Daily and monthly module temperature variation for 9 different modules
Özden, Talat; Tolgay, Doga; Akinoglu, Bulent G.
One of the main parameter affecting the efficiency of PV modules is the module temperature. In this respect, outdoor testing of modules is very important to determine the temperature dependent performances and degradation rates. In this work, we analyzed the module temperatures of 9 different modules tested in the outdoor testing facility of METU-GUNAM, Ankara (latitude ∼40°N, in Central Anatolia and the climate is dry continental). The tested module types are two CIS (identical), one μc-Si/a-Si, one Poly-Si, three Mono-Si (two identical), one HIT and one bifacial. The module temperatures can reach up to 76°C while the ambient is around 39 °C during summer days. Monthly average module temperatures can reach up to 33.7°C (CIS) while the monthly average ambient is at 26.0°C and drops down to 1 °C while average ambient temperature is about the same as average module temperature. The results showed that the monthly averages of module temperatures differences are maximum during summer (∼3.5°C) and minimum during winter (1.1°C). It is interesting that the two CIS modules have the highest monthly average module temperature and although they are supposed to be identical their temperatures differ significantly. Bifacial and HIT module temperatures are lower than the Mono-Si modules. One of the two identical Mono-Si modules was not cleaned and its module temperature is always lower than the one that was cleaned periodically, as expected. In this work, we also present the results and discussions on the spatial variations of measured module temperatures of PV panels.
- BildiriYalnız künye2018On the Yearly Performance of a Bifacial PV Module in Central Anatolia - Turkey
Özden, Talat; Turan, Raşit; Aklnoǧlu, Bülent Gültekin; Zaz, Y.; Essaaidi, M.
With the tremendous increase in the photovoltaic (PV) power plants world-wide remarkable decreases in their installation prices per watt are attained mainly due to economic scale effect. This brings questioning to increase their energy yields by considering any possible way like fabricating bifacial solar modules. Present study is on the performance analysis of a bifacial PV module using one-year outdoor testing results in Ankara-Turkey. The module performed very well and reached a specific yield value of 1750 kWh/kWp. This value for Central Anatolia region is well above the values predicted (and suggested) by the local authorities. The efficiency and performance ratio variation with respect to ambient and module temperature are obtained. The calculated dependence of efficiency on the module temperature is found to be η=-0.073Tmod+18.05, and the maximum measured module temperature is about 70 °C. The results show that the bifacial modules have the potential to replace the mono facial modules that are now dominating the PV market.
- BildiriYalnız künye2018Seasonal Variation of the Monthly Efficiencies of Thin Film PV Modules
Özden, Talat; Turan, Raşit; Akmoǧlu, Bülent Gültekin; Zaz, Y.; Essaaidi, M.
Outdoor testing of solar photovoltaic (PV) modules must be carried out at different climates as PV power plants nowadays are installed and continues to be installed in many countries. Present study is outdoor testing results and analyses of 5 thin film modules in Ankara, Turkey. The analyses are carried out using monthly efficiencies of the modules that are derived using the energy yield and input. The average efficiencies of the CIS, CIGS and μc-Si/a-Si thin film modules are. We present the monthly and average efficiencies and discuss their variations with the parameter: input, ambient temperature and relative humidity. We also carried out seasonal analyses using Pearson's correlation coefficient and find out that the efficiencies are differently dependent on the above mentioned parameters. This arose a new open question on differentiation of the strength of the effect of each parameter on the monthly efficiencies.
- BildiriAçık Erişim2017Effect of Ambient Conditions on Monthly Performances of Three Different PV Arrays
Özden, Talat; Akinoglu, Bulent G.; Turan, Rasit; Martinez, V; Gonzalez, J
Solar PV cells may be mainly divided into two parts as crystalline and thin film. Mono-crystalline silicon (e.g. Mono-Si) and microcrystalline based amorphous silicon and other thin films (e.g. gc-Si/a-Si and CdTe thin films) are widely used PV cells in the arrays. The outdoor performances of these systems depend on some climatic parameters and conditions, and it is important to understand how the monthly efficiencies vary with these parameters. In the present study, the data obtained from three grid connected PV arrays of Mono Si, a-Si/p.c-Si and CdTe thin film that were operated for 41 months in Ankara-Turkey is analyzed. The results showed that Mono-Si an-ay performance depends on the 5 parameters of outdoor climatic conditions while a-Si/gc-Si and CdTe thin film arrays performances arc not significantly affected by the variation of the climatic parameters. The possible reasons are discussed in details.
- BildiriYalnız künye2012Designing a load agent for power management with a multi-agent home automation system
Özden, Talat; Okumuş, Halil Ibrahim
In this study, a load agent design is performed for the power management which lets us use existing electrical energy for consumer's needs, comfort and criteria in the areas such as flats and commercial buildings that independently meet their energy need from renewable energy sources. The load agent is designed on the basis of radio-frequency communication so it is a wireless communication system which also has the ability of switching off or making power flow by measuring current of the load. The agent has a flexible structure in order to be compatible with all ambient equipments. It can work with all equipments on the system properly, without any hardware changing. And this is shown in the paper.
- BildiriYalnız künye2012Control of an optimum modelled air heating system and real time simulation
Özden, Talat; Tuǧal, Harun; Okumuş, Halil I.
In this paper, a controller was designed for air heating system and parameters of controller were calculated. A real time simulation of system was done to compare properties of controller both in simulation and real time simulation. To design a controller the system should be modelled. The modelling processes have done in our previous article was about modelling of air heating system.
- BildiriYalnız künye2011Comparison of state space controllers with two different observers on an identified water tank system
Özden, Talat; Ciba, Osman Nuri; Okumuş, Halil Ibrahim
In this paper, identification of a water tank system is performed, and controller and observer for identified system are constructed. Identification is done via Linear Black Box Identification which consists of unknown parameters; need to be estimated from measured data. Firstly, PRBS Signal is built using data, which is achieved by analyzing step response of the plant and considering that the change in the input signal may not be too large since we are going to use a linear model to indentify a nonlinear process. Considered linear models are ARX, ARMAX and OE, whose results are compared using different criteria such as simulation, correlation, and pole-zero plots. And the chosen model which is an Armax model will be given explaining the reasons why it is chosen. In the next step, controllability and observability tests are performed for chosen Armax model and observer and controller designs are performed. Predictive and filtering observers are constructed to observe the system and state space feedback controllers with and without integrators are constructed to control the system. Depending on the achieved observers and controllers, response of real system and simulation are compared to find best controller and best observer for the water tank system.