Alumni

The characteristics of the wind differ temporally and regionally due to geographical differences, topographic structures of the regions and different warming of the earth. The potential of the wind is determined by factors such as wind speed, blowing direction and blowing time. Likewise, these factors should be examined when establishing wind power plants. However, not only the wind speed and capacity factor, but also technical, environmental, economic and social criteria should be considered in the selection of suitable areas where WPPs will be installed. Different issues such as the difficulties encountered in the process of choosing the location of wind power plants,and optimizing our responsibilities towards nature for today’s economic conditions and for the investor should be examined together. The working principle of Geographic Information Systems is to examine many criteria together. This thesis study aims to develop a site suitability analysis method using Geographic Information System and Analytical Hierarchy Process techniques for the sustainability of wind energy and the planning of the areas where WPPs will be installed, as a solution to the problems mentioned above, and to apply this method in a sample field. İzmir province was chosen as the study area. 14 different criteria were used in the evaluation of the study. These; wind speed, distance to highways, distance to bird migration routes, residential areas, forest areas, agricultural areas, industrial and commercial areas, urban green areas, distance to fault lines, salt flats and lakes, maquis and natural vegetation, slope and distance to energy transmission lines. The aim of this study; to decide on the important criteria and constraints, to evaluate them with the help of Multiple Decision Analysis approach, to put them in a certain order and to transfer this order to a visual map with the help of Geographic Information Systems to create a suitable site for wind farms. As a result of the study, suitable sites for wind farms in İzmir, the biggest city of the Aegean Region, were selected and the positive and negative aspects of these sites were included in the evaluation.According to the results of the study, very suitable areas were determined in Çeşme district and Bergama district. And the result obtained is shown in the map. Keywords: Wind, energy, geographic information system, Multi criteria decision analysis, environment.

Energy forestry includes all processes and planning to cultivate trees that can be used in solid, liquid, and gas fuel production. By energy forestry, which is carried out by growing fast-growing non-edible plants, national energy supply security is protected by native resources and reduces greenhouse gas emissions from fossil fuels. Since energy forestry practices are also included in afforestation, they also constitute an essential carbon sink. Realizing this potential, it is a complex task to spatially plan energy forestry implementation. The establishment of multi-use forest plantations requires integrating spatial information technologies such as Geographic Information Systems (GIS) based decision support mechanisms and remote sensing. In this study, a comprehensive model based on R. pseudoacacia, P. aculeata, A. altissima, L. leucocephala, M. azedarach, and P. euphratica trees was developed, and it is aimed to determine the areas where energy forestry can be done with GIS-based Multi-Criteria Decision Analysis (GIS-MCDA) method. The study mainly consists of the following stages: (1) Determination of criteria (soil pH, sand content, clay content, depth, elevation, slope, aspect, temperature, and precipitation) for the cultivation of model trees, (2) spatial database development, (3) standardization of criteria, (4) determination of criteria weights and (5) determination of suitable areas for energy forestry with weighted linear combination method in GIS-MCDA model. While using the fuzzy technique for soil and topography data in the standardization phase, climate data are standardized by the Plant Climate Suitability Model (PCSM), in which the ecological characteristics of the plant are also integrated. Based on expert opinions, the Analytical Hierarchy Process was used in the factor weighting phase, and spatial suitability maps for energy forestry were obtained according to both the present and the future period (2050). In determining how energy forestry will be affected by temperature and precipitation changes in the future period, the projection data of future climatic conditions (HADGEM2-ES RCP4.5) have been integrated into PCSM. In addition to obtaining the spatial suitability of the studied species, comprehensive studies on the control of plant mobility and species competition in and around the plantations to be cultivated and multi-purpose use of these trees other than energy raw materials are presented. Besides, the CO2 reduction rates of forest plantations extending from the present to the future period were determined by evaluating the carbon sink potentials of the suitable areas together with the CO2 emissions from today’s energy sector. During both literature review and analysis, this study, which was separated from previous studies, reveals that at least 70% of CO2 emissions from the energy sector today can be kept by 2020 and 97% by 2030 with the developed model. All of these qualities and the striking findings of this study can be included in the “intended national contribution statements,” “energy planning,” and “greenhouse gas reduction policies” proposed by the United Nations to countries. This study creates a national road map that will yield benefits in many sectors and areas. The thesis’s motivation is to develop a practical and useful model for sustainable energy forestry to increase our country’s renewable energy potential and reduce CO2 emissions in combating climate change and reducing foreign dependency on energy. The thesis study results have a guiding nature for future planning and scientific studies in light of all these issues mentioned.

Today, the energy resources used to generate electricity are largely in fossil based. In addition to the fact that fossil-based resources are limited, the lack of equal use of these resources in worldwide leads to price imbalance and political crises. Resources that can be used as an alternative to fossil resources are renewable energy sources which are sustainable, environmentally friendly and clean. The use of solar and wind energy from renewable energy sources has been increasing in recent years. Turkey is located in a very fertile region in terms of renewable energy sources. In particular, Turkey has a very high potential of solar energy. Solar energy is one of the cleanest, sustainable and low environmental impact energies, and reduces dependency on energy as it is a domestic resource. Photovoltaic Power Plants (FVGS) is one of the most intensive solar energy applications. Since the initial investment cost is high for FVGS, choosing the right and effective place is very important. Site selection of solar power plants (SPP) depends on the criterions such as land quality, weather conditions of the region, distance to electricity transmission lines, agriculture and environmental protection areas. Therefore, SPP site selection is a critical issue for investors. Multi-criteria decision methods are often used for different site selection studies. In this study, the site suitability of the SPP lands in İzmir was evaluated by Geographic Information System (GIS) with Multi Criteria Decision Making (MCDM) tools and Analytical Hierarchical Process (AHP) method. In the study, for solar power plant location selection in the working region of İzmir, as the first step, 6 location selection criteria were determined. These are solar energy potential, slope, aspect, land use, distance to energy transmission lines and distance to roads. These criteria belong to different areas like orographic, economic, land use, climatic and environmental. The climatic solar energy potential has emerged as the most important criterion since it defines the potential photovoltaic electricity generation of a particular field. Weight percentages of the criteria were calculated using AHP method. After the weights were obtained, the relevant data were collected and the necessary analyzes were made with the help of GIS software ArcGIS and the most suitable places for FVGS were found in İzmir province. The final result map obtained in the study was divided into 6 classes as “unsuitable”, “low suitable”, “moderate”, “suitable”, “very suitable”, “best suitable”. Each class has a different percentage. According to the results of the analysis, the field data of the classes are as follows; unsuitable 1,046,539,03 ha, low suitable 0,01 ha, moderate 31,737,17 ha, suitable 40,561,14 ha, very suitable 36,287,02 ha, best suitable 14,499,51 ha and total area of 1,169,623,88 ha were calculated. The ratio of classes to the total surface area of İzmir province is as follows; 89.48%, 0.00%, 2.71%, 3.47%, 3.10%, 1.24%. As a result of this analysis, it has been determined that the area with the highest rate for the selection of suitable place in the FVGS of İzmir province (not including the unsuitable class) is “suitable” and “very suitable”.

While the use of renewable energy sources is becoming widespread, many research and development studies are carried out to increase the application areas of photovoltaic power systems. In particular, research on system parameters affecting productivity and productivity is increasing every passing day. In this study, effects of snowfall on production values of photovoltaic power systems were investigated. In the simulation programs, which are commonly used, the snow load accumulated on the panel surface in the days following the snowfall is prevented. Within the scope of this study, a meaningful connection was tried to be established by comparing the production values of a photovoltaic power system established in Erzurum province where heavy snowfall is observed and the estimated data of a simulation program used in the preparation of power plant feasibility reports for two years. According to the results obtained in the light of limited data, for a day reinterpreted with the profit model, when the total daily production values are considered, 90% proximity to the actual production value is obtained compared to the initial results of the simulation. However, it should be kept in mind that this result corresponds to only one day in the data set and the model shows significant deviations on different days. Since there are many climatic parameters that affect snowfall and residence time, it should not be overlooked that the result of the study is a local assessment for the designated plant.

Demand for renewable energy is increasing due to problems such as the increase in demand, global warming, and rapid depletion of fossil fuels. However, the impact of renewable energy on environmental conditions and the discontinuous production have a negative effect on the efficient use of energy. Therefore, the stored energy must be properly distributed to the loads. Load management systems are needed to minimize the energy imbalance in production and consumption. In systems where there is no load management, in view of the worst scenario, the battery size and system power are calculated high and the installation cost increases. It is aimed to reduce the installation cost and to ensure the system to be efficient and long-lasting with intelligent load management. In this study, load control of the devices in a house which is off grid has been performed. Based on user comfort and criteria, 4 priority load classifications were controlled according to the calculated SOC value. The control system which is compatible with different situations and makes autonomous decisions has been developed by using PLC. In the SOC calculation, coulomb counting method which is widely used in literature is preferred. Power optimization is aimed to keep the loads with high priority in the system. The touch HMI panel is used for the user to read and write data in the system. Thus, the battery is used efficiently and the user’s comfort is increased.

Despite being non-suitable within environmental parameters, uncontrolled disposal sites are stil being used as a part of the solid waste management and many of these sites in many places are waiting to be fixed, as the implementation of sanitary landfills are fairly new. Uncontrolled disposal sites are fields, which require serious funding and have major potential, as they are a means to produce energy. Therefore, the question of whether the producing energy from the stored gas could cover the expenses of the rehabilitation facility is an important one for a newly closed uncontrolled disposal site. Within this context, a sample uncontrolled disposal sight was selected and the rehabilitation process and technical and economical feasibility of its energy production was monitored. Rehabilitation and energy production system of the sample field’s initial set up expenses and the income from it’s elecricity production were calculated. In order to examine the economical feasibility, LandGEM model was used when estimating the prospective storage gas and potential energy production levels were calculated. According to the findings of the study, while the yearly average of energy production of the sample field was 0,897 MW in 2018, approximate prediction of energy production was valued as 0,823 MW in the same year. Having considered the fact that the field will be operated for 15 years, it was discovered that the profits will be 3,18 million $ within the context of cost-analysis findings. In conclusion of the study, it was realised that the rehabilitation process for the uncontrolled disposal sites was feasible in technical and economical terms, yet, it’s profit margin was determined as low yield. Keywords: Energy production, storage gas, municipal solid waste storage areas, rehabilitation, economy.

Most of the energy the world needs is provided by the Sun. Among renewable energy power plants, solar energy is a type of energy production with high potential in terms of resources. Renewable energy plants eliminate the dependence of countries on foreign sources. Turkey has a fairly good geographical position in terms of renewable energy potential. However, the level of renewable energy production is low. Several feasibility studies in Turkey and power plant installation is carried out due to high level of solar power potential. In this study, it is aimed to determine the suitable areas where solar power plants can be established within the boundaries of Izmir province. Firstly, the factors that may affect the installation and efficiency of solar power plants have been identified. Regional data were collected by considering these factors. Percentage impact ratio was determined by software analysis of each factor effective to determine the suitability of the land. By combining the percentage effects of the determined factors with a method supported by geographic information system, the analysis of the sites within the boundaries of the study area was conducted. Lands not suitable for the installation of the PV are excluded from the assessment. When the remaining suitable land was classified, was calculated by taking the effect of radiation and temperature 70,3%, ENH 7,7%, slope 14,8%, see 7,2% PV plant. In this direction, the engineering, economic and social criteria that will determine the technical suitability of the areas where solar power plants will be established are determined and efficient areas where solar power plants can be established have been determined.

The study aims to investigate the torrefaction of wood chips and nut shells and the identification of optimimum temperature and residence time parameters. Torrefaction is a thermal process with a temperature range between 200 °C-300 °C and residence time 10 to 60 minutes. As a result of this process, hydrophobic biochar with increased energy density and with high grindability, is obtained. This biochar can be used in a coal combustion system with coal or as fuel in gasification systems. Temperature, particle size, residence time, heat flow, biological properties of biomass are the parameters that affecting the process. In this study, torrefaction of pine shavings and nut shells which sent by TÜBİTAK MAM E.E. was carried out in a muffin furnace which has 0-1500 °C temperature range and 10 ° C/d heat flow. The experiments were carried out at 3 torrefaction temperatures (260 °C, 280 °C, 300 °C) with 30 and 60 minutes residence time for each temperature value. As the temperature and residence time increased, the mass yield and the volatile matter ratio decreased and the thermal value and the fixed carbon ratio increased for both feedstocks. The effect of temperature is greater than the effect of residence time. It was concluded that 300 °C and 60 minutes residence time processing conditions for wood chips and nut shells would be the most suitable production conditions for co-combustion of coal and biochar in the fluidized bed.

In this thesis, suitable areas for switchgrass cultivation - what is one of the biofuel material and can be alternative energy source apart from fossil fuels- via GIS, AHP and RS techniques. To make a decision for cultivation areas, first of all, the constraints and factors were identified and created widely database with obtained and producted data. Then the comprehensive multi-criteria decision analysis model was created and used for seven scenarios with variable factor suitability intervals. In this model for all scenarios; (1) Constraints were eliminated from whole working area, (2) Factors were standardized with FUZZY logic method to normalize the factor’s suitability intervals for switchgrass cultivation, (3) All factor’s weights were calculated with AHP matrix, what were created with specialists and (4) All these steps were integrated to MCE module and results were obtained via weighted overlay in MCE. Developed criteria evaluation model was applied in 1.2 million hectares of İzmir. In this area, all agricultural areas (624. 023 ha) and forested areas were constrained; thus marginal areas (49.612 ha-non-agricultural area) were determined. In these marginal areas, factor standardisation and factor weighting were integrated to MCE; thus the results were obtained in seven variable scenarios. In the first scenario (low elevation and slope values existed), the areas between middle and high suitability to cultivation were calculated as 18.899 ha. In the other third scenario (high evaluation and slope values existed), the areas between middle and high suitability to cultivation were calculated as 28.484 ha. When the switchgrass yield is tackled, the determined areas can supply approximately 40 % of all the fuel-oil demand of the city. This value is very significant for the İzmir, what is the third populous city of the Turkey. The developed model in this thesis can be useful for decision makers, managers and institutions. The model steps and results and recommendations have also very important qualification to bring forward all future works about this subject. Keywords: Geographic Information Systems, Multi Criteria Evaluation, Switchgrass, Remote Sensing, Analytic Hierarchy Process