Suchergebnisse

The objective of this thesis is to optimize the design parameters of a large scale photovoltaic power plant in order to find its optimal size having the lowest payback period. A methodology is proposed to guide the investors and technical staff in the design of such a system, with core emphasis on self-consumption policy. A flowchart of the process, that uses site survey, system components, associated costs, meteorological data, load analysis, is created. A three-step algorithm is developed in order to solve the optimization problem that searches for the PV plant size having the lowest payback period. The first phase of the algorithm is to minimize the energy fed into the grid for free of charge. In other words the self-consumption is maximized. The decision variables such as the tilt angle of the PV modules, number of PV modules connected in series across a string, number of strings connected to an inverter and the number of inverters are calculated in this phase. The second phase involves maximizing the occupied land area and determining layout of the PV plant. The layout is based on consecutive PV blocks in the installation area. Number of rows and columns in a PV block are obtained in this phase. Last phase is based on the calculation of the optimal size of the PV plant, which has the lowest payback period, by using an iterative approach. Net present value analysis is used as a supplementary tool in order to allow the investor to make better judgment on the project. A case study is carried out in Cyprus International University campus in order to support the proposed methodology. The lowest payback period is achieved at 6.18 years with the total installed capacity of 712 kWp. The payback period results iv calculated by the proposed algorithm and PV*SOL Premium, which is one of the most commonly used PV planning software in the PV market, for each increment in the PV plant size are compared. The difference between the payback periods obtained from the proposed algorithm and PV*SOL Premium is 1.79% on average and 0.34% at the optimum PV plant capacity. According to the case study, a 712 kWp self-consumption PV plant can be installed on 9055 m2 of land area. The initial investment cost is calculated as € 1,063,700. The system can consume 97.92% of its own annual production while only 2.08% of the annual PV energy generation is exported to the grid. The system reaches a self-sufficiency ratio of 25.02%. The net present value is calculated as € 7,091,000. Keywords: Solar energy, large-scale PV power plant, non-incentivized self-consumption, design optimization. ; ÖZ: Bu tezin amacı, büyük ölçekli fotovoltaik (FV) enerji santralinin tasarımını optimize etmektir. Öz tüketim politikasını temel alarak, böyle bir sistemin tasarımında yatırımcılara ve teknik personele rehberlik etmek için bir yöntem geliştirilmiştir. Bu bağlamda tüm süreci gösteren ve saha araştırması, sistem bileşenleri ile ilgili maliyetler, meteorolojik veriler, yük analizi konularını kapsayan bir akış şeması oluşturulmuştur. En düşük geri ödeme süresi olan FV santralini bulmak için üç adımdan oluşan bir optimizasyon algoritması geliştirilmiştir. Algoritmanın ilk aşaması, şebekeye ücretsiz olarak verilen ancak ekonomik karşılığı olamayan enerjiyi en aza indirgemektir. Bir başka değişle öz tüketimi en üst seviyeye çekmektir. FV modüllerinin eğim açısı, bir dizi boyunca seri bağlanmış FV modül sayısı, bir eviriciye bağlı dizi sayısı ve evirici sayısı gibi karar değişkenleri bu aşamada hesaplanır. İkinci aşamada, kullanılan arazinin hesaplanıp, FV santralinin yerleşimi belirlenir. Bu aşamada bir FV bloğunda bulunan yatayda ve dikeyde yerleştirilen modül sayıları belirlenir. Son aşamada ise tekrarlanan bir yaklaşım kullanılarak, en düşük geri ödeme süresi olan FV santralinin optimum büyüklüğünü hesaplanır. Net bugünkü değer analizi, yatırımcının projeyle ilgili daha iyi karar vermesine olanak tanıyacak şekilde geri ödeme süresi analizi ile birlikte kullanılır. Önerilen metodolojiyi desteklemek için bir üniversite kampüsü için durum çalışması yapılmıştır. En düşük geri ödeme süresini olan 6.10 seneyi veren FV santralinin optimum kapasitesi 712 kWp olarak hesaplanmıştır. FV santralinin büyüklüğündeki her artış için önerilen algoritma ile hesaplanan geri ödeme süresi sonuçları PV*SOL Premium yazılımından elde edilen sonuçlar ile karşılaştırılmıştır. Önerilen vi algoritmanın sonuçları ile PV*SOL Premium yazılımından elde edilen sonuçlar arasında yalnızca %3'lük bir fark olduğu görülmüştür. Yapılan durum çalışmasına göre, 9055 m2 arazi üzerine öz tüketim prensibi ile çalışan 712 kWp gücünde bir FV tesisi kurulabilmektedir. Sistemin ilk yatırım maliyeti 1.06.700 € olarak hesaplanmıştır. Sistem, kendi yıllık üretiminin ,92'sini tüketebilirken, yıllık PV enerjisinin yalnızca %2,08'ini elektrik şebekesine verilmektedir. Sistem, ,02'lik kendi kendine yeterlilik oranına ulaşmaktadır. Net bugünkü değer 7.091.000 € olarak hesaplanmıştır. Anahtar Kelimeler: Güneş enerjisi, büyük ölçekli FV santrali, teşviksiz öz tüketim, tasarım optimizasyonu. ; Doctor of Philosophy in Electrical and Electronic Engineering. Thesis (Ph.D.)--Eastern Mediterranean University, Faculty of Engineering, Dept. of Electrical and Electronic Engineering, 2017. Supervisor: Prof. Dr. Osman Kükrer.

Segregation of hydrophobic and hydrophilic domains is central to the formation of biological membranes, lipid bilayers and micelles and is also involved in protein folding. In this paper we introduce a new empirical equation which enables the calculation of the free energy of solvatation for all protein constituents.
The free energy of solvatation consists of two components ; the first derives from interactions between the constituent atoms of the protein, while the second results from interactions between protein and solvent, as expressed by the surface area of protein atoms covered by solvent molecules. The total energy of the macromolecular system is distributed along the torsional axes of the protein.
We propose here that protein folding can be represented as the aggregate of two computational procedures. The first step calculates the initial structure subsequently used in the molecular dynamics approach. For this purpose a local minimum energy procedure defines the most stable secondary structure of each amino acid which occurs during the theoretical conformational transition of the protein from an ideal alpha-helix to an ideal beta-sheet. The second calculation procedure consists of a molecular dynamics approach applied to the torsional axes of the protein, to identify the structure of the protein with a minimal total energy. This " ab initio " method therefore requires no

Investment risks of utility-scale PV systems may arise from a wide range of sources: political stability in a region, interest rate levels and currency exchange rates or future energy price. However, the presence of stable political and economic conditions and feed-in tariffs or power purchase agreements may limit interest and price risks to acceptable levels. The technical risk of deviations between expected and actual life-time energy yield of a PV power plant is mostly influenced by the quality of energy yield predictions in case that system components correspond to their datasheet and guaranteed values and the maintenance concept is applied as expected. Recent publications estimate the standard uncertainty of life-time energy yield predictions to about 8%, which directly contributes to overall investment risk. In this paper we analyze two different strategies to reduce the influence of uncertainties of energy yield predictions on investment risks. The first strategy is diversification of risk, i.e. investing in a portfolio of systems. The second strategy is related to adjusted investment periods. It is concluded, that both strategies as well as the combination of these strategies are able to significantly reduce uncertainties. The resulting uncertainty of the lifetime energy yield for the combination of both approaches is estimated to about 3%.

non-peer-reviewed ; The 'European Green Deal' attributes a pivotal role to the decarbonisation of the EU energy system in order to reach climate objectives in 2030 and 2050. Photovoltaic energy (PV), among the plethora of renewable energies, can greatly contribute to EU energy system transition. A recent study carried out by the Joint Research Centre shows that, inter alia, the yield, quality and long-term performance of PV modules present an improvement potential, which could be tackled by means of regulatory instruments, such as the Ecodesign Directive and the Energy Labelling Regulation. In standardisation terms, the durability of a product, intended as an estimator of its technical lifetime, can be defined as the 'ability to function as required, until a limiting state is reached'. The PV modules have a typical annual degradation rate of 0.8%-1%, which leads to 80% of the initial nameplate rating at 20-25 years.