Farklı Bina Formlarında Güneş Pili Uygulamalarının Enerji Ve Maliyet Etkinliği Açısından Değerlendirilmesi

Abstract

Bu tez çalışmasında farklı bina formlarında güneş pili uygulamalarının enerji ve maliyet etkinliği değerlendirilerek, güneş pili uygulamalarındaki en etkin bina formunun ve güneş pılı uygulama seçeneğinin tanımlanmasına yönelik bir yaklaşım geliştirilmiştir. Çalışma beş bölümden oluşmaktadır. Birinci bölümde, alternatif enerji kaynaklarından güneş enerjisinin önemi ve güneş enerjisi sistemlerinin aktif ve pasif sistemler olarak binalarda kullanılması açıklanmıştır. İkinci bölümde, aktif güneş enerjisi sistemlerinden binalarda kullanılabilen bir sistem olan güneş pilleri tanitilarak, güneş pili bileşenleri aciklanmistir. Güneş pili sistemleri farklı özelliklerine göre sınıflandırılmıştır. Üçüncü bölümde, farklı bina formlarında güneş pili uygulamalarının enerji ve maliyet etkinliği açısından değerlendirilmesine yönelik bir yaklaşım binalarda güneş pili uygulamalarında enerji harcamalarını ve maliyeti etkileyen değişkenler anlatılarak tanıtılmaktadır. Dördüncü bölümde, farklı bina formlarında iklimsel konfor ve enerji korunumunu sağlamak amacıyla güneş pili uygulamalarının enerji ve maliyet etkinliği açısından performanslarının değerlendirilmesini hedefleyen yaklaşımın uygulaması yapılmıştır. Ayni hacim ve ayni bina yüzey alanına sahip 7 farklı bina formu için, düz çatı, kırma çatı ve beşik çatı önerildiğinde, çatı ve/veya cephelerde güneş pili uygulamaları gerçekleştirilmiştir. Binaların yıllık toplam enerji (ısıtma+sogutma+aydınlatma) yükleri, farklı güneş pili uygulaması kombinasyonları ile elde edilen kazançlar hesaplanarak karşılaştırmalı olarak değerlendirilmiştir. Güneş pilinin uygulandığı çatı tipi, açısı, yönü ve alanı gibi değişkenlerin güneş pili ile elde edilen enerji kazançları üzerindeki etkisi tartışılmıştır. En yüksek kazancın elde edildiği güneş pili uygulama seçeneği maliyet etkinliği yönünden değerlendirilmiştir. Beşinci bölümde sonuç ve öneriler yer almaktadır.

In Turkey, more than half of the energy requirement is met by imports because of limited national energy resources. A considerable portion of total energy is consumed in the residential sector, especially for heating, cooling and lighting of buildings. Therefore; increasing energy efficiency in buildings becomes crucial in order to reduce total energy consumption. An energy efficient building would ideally rely on alternative energies as its main source to meet its heating, cooling and lighting needs. An optimized passive design integrated alternative energy systems can greatly reduce the energy consumption in buildings. One way to increase energy savings is to reduce the consumption of fossil fuels and to use alternative energy resources which are clean, cheap and unlimited. Photovoltaics (PV) panels are one of the energy efficient systems which use solar energy to provide necassary electrical energy for heating, cooling and lighting in buildings. Rooftop installation is the most common mode of PV application in buildings, but not the only one possible. Installation in South, East and West façades is also possible. Building facade area and orientation are the main determinants of the PV panels efficiency. Therefore, building form which determines the facade area of the building is one of the most important design parameters affecting electricity generation by PV panels. It is possible to design a lot of building forms that yield the same volume, but different facade area. Therefore, the ratio of total facade area to building volume (A/V) is an indicator in describing the building form. The aim of this study is to develop an approach to determine the most efficient Building Attached Photovoltaic Panel (BAPV) application on different building forms by evaluating energy and cost performance. The study consists of 5 chapters. In the first chapter, the potential of energy sources are compared and the importance of solar energy, which is one of the most important alternative energy sources, is emphasized. Passive and active solar systems applied on buildings are explained with their basic specifications. In the second chapter, Building Attached Photovoltaic Panel systems which can be applied as an active solar systems on buildings are discussed. The basic working principles of photovoltaic systems are explained and the components of the building atteched phovoltaic systems (such as solar cells, module, panel, inverter, battery, charge control units and other components) are defined. The classification of PV systems is described. Building Attached Photovoltaic Panel systems are classified according to their material types (polycristal sylyssium, monocristal syslisum, thin film, amorf silysium etc.) connection types (serial, parallel), grid connection types (on-grid, off-grid, hybrid) , structural characteristics and transparency characteristics. PV related factors which influence the energy loads and costs, are analyzed. These factors are classified as follows: • Conditions related to cells and modules types • Battery efficiency • Invertors efficiency • Surface area • Angle of incidence • Shading • The variation of PV panel performance in long term period In the third chapter, a new approach aimed to evaluate BAPV systems on different building forms from the energy efficiency and cost effectivity point of view is introduced. This method consists of the following steps: • Determination of the regional climatic datas (solar radiation, outdoor temperature, outdoor air movement, outdoor humidity) • Determination of the internal climatic datas ( indoor temperature, indoor surface temperatre, indoor air movement, indoor humidity) • Determination of design variables affecting the evaluation of energy and cost effectivity of BAPV for different building forms. These variables are; - site and the location of the building according to the other building, - building form alternatives and the orientation of the building, - using period of the building according to the function of the building - optical and thermophysical properties of building envelope (the absorptivity of the building envelope, the transparency ratio, the value of the required overall heat transfer coefficient of opaque component, the detail of opaque component which satisfied the required overall heat transfer coefficient). • Calculation of annual total energy (heating, cooling and lighting) loads for different building forms. • Determination of variables related to PV system application. These variables are; - PV system application alternatives - PV system types - evaluation of energy efficiency of PV systems applied on the building envelope of different building forms. • Economic evaluation of high performed alternative for different building forms. The steps for the economic evaluation are as follows: - Determination of an economic evaluation technique for PV system application - Preparation of necessary datum and hypothesis to apply the chosen evaluation technique (Preparation of the inıtial capital cost of PV systems, preparation of the manitenance and repair cost, preparation of the management cost, preparation of disposal cost and salvage value, determination of the study period and determination of the escalation and discount rate). - Calculation and comparison of PV system alternatives’ Life Cycle Cost for different building forms - Determination of the most convenient building form and PV system application alternative with respect to their life cycle costs The fourth chapter consists of the application of the method introduced in the third chapter to residential buildings in different regions of Istanbul. The method is applied for 7 different building forms with the same A/V ratio. Each building form is evaluated with flat roof, gable roof and pitched roof. Buildings were assumed to be oriented toward the main directions (S, E, W, N). and located on a flat parcel of land devoid of incline, and not shaded by other buildings. The indoor air temperature in all spaces of the building was assumed to be equivalent and calculations were carried out by considering each building as a single zone. The thermal performance of the different building forms under the effect of different PV application systems are evaluated by calculating the annual heating, cooling and lighting loads by using the simulation program “ Design Builder” that is the user friendly visual interface of Energy Plus. Climatic data has been taken from, IWEC (International Weather for Energy Calculations) weather data in the Design Builder. Results of the application are compared by means of graphic systems. In the fifth chapter, results of the present study were explained.