Renewable Energy Systems (M. Sc.)
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The global population is anticipated to experience a significant surge by 2050, posing profound challenges in ensuring food and energy security. Concurrently, the prevalence of hunger, exacerbated by pandemics, climate shocks, and conflicts, underscores the urgency to enhance agricultural productivity and energy efficiency. Agriculture currently accounts for 70% of freshwater consumption and 30% of global energy usage, requiring innovative solutions to meet increasing demands. In this context, Agri-Photovoltaic (Agri-PV) systems emerge as a promising approach, integrating agricultural practices with solar technology to enhance food production and energy generation simultaneously. These systems not only address the pressing need for sustainable food and energy sources but also offer benefits such as resilience against extreme weather events and income diversification for farmers.
This study investigates the potential of Agri-PV systems to address power outages in rural areas of Kissane in Morocco, as well as Bouda in Algeria. These areas are characterized by weak grid networks. After developing the load profiles of farms and households in the case study areas based on real data and literature, the PV-SOL software is utilized to estimate the size of the photovoltaic system. After simulation in the software and considering the type of Agri-PV substructure, three different scenarios for sizing the system are taken into account. The first scenario aims to cover all energy demands for both farms and households, the second focuses solely on farms, and the third focuses only on household energy requirements.
The results reveal that with six hours of power outage in a day, Kissane requires a 39 kWp Agri-PV system with an 85.31 kWh battery to fulfill its total energy demands. For farms alone, a 38 kWp system with an 82.04 kWh battery is necessary, while households, due to cooperative arrangements and few houses, need only a 1 kWp system with a 3.27 kWh battery. In Bouda, facing six power outages in a day, a 46 kWp system with a 144.34 kWh battery is required for total energy, 41 kWp with a 125.78 kWh battery for farms, and 5 kWp with an 18.56 kWh battery for households. Economic analysis favors Morocco due to higher electricity prices, yielding Kissane a positive 8.69% internal rate of return (IRR) and a competitive 10.95 cent/kWh levelized cost of electricity (LCOE). In contrast, Bouda faces economic challenges with a -2.93% IRR and a 13.77 cent/kWh LCOE, necessitating financial incentives for viability.
Keywords: Agri-Photovoltaic (Agri-PV), power outage, load profile, grid network, rural energy security, Morocco, Algeria
The dairy farms form a vital part of German agriculture and consume significant energy for their operation. Germany is working towards energy transition to transform the existing fossil fuel-nuclear system to a sustainable energy system that relies on renewable sources due to various societal and political demands. As the energy demand is increasing due to the rise in population, there is also a growing push in Germany to adopt energy efficient technologies and measures to reduce energy waste. There is a scope for improving the energy efficiency in dairy farms. Using energy optimization techniques can help reduce the load on energy suppliers as well as increase cost savings for farms.
German farmers are adopting newer digital technologies to achieve optimization of energy in their farms. One of the key tools in realizing energy optimization is the Energy Management System (EMS). The use of EMS in the case of dairy farms has been reviewed and presented in this work. The objective of the study is to investigate the potential of energy optimization in dairy farms. Efficiency measures like replacing inefficient farm equipment are necessary to achieve energy efficiency. These measures are discussed in detail and their potential to save energy in dairy farms is presented. A comparison of all these measures is studied and how much energy savings can be obtained is reviewed.
The use case scenario of EMS in different applications is presented as an indication of possibilities for energy savings using EMS. Furthermore, how the AI technology in combination with EMS can be used in farms and its benefits in dairy farming is reviewed. The types of farms on which the energy optimization measures can be implemented in an ideal case scenario are reviewed. The result of the study shows that there is vast potential for energy optimization in German dairy farms. Thus, the presented work can be further studied to identify further optimization possibilities with the advancement of AI and newer technologies.
Energy independence of commercial buildings is a critical aspect of modern construction. In the context of a planned office building project in Ekibastuz, Kazakhstan, located in an extreme climate with unstable coal energy tariffs, it is necessary to determine the energy needs and understand how to cover them. This thesis focuses on determining the level of efficiency in the use of electricity, reducing dependence on local energy suppliers, and integrating alternative sources. The energy assessment was carried out using software tools such as Autodesk Revit and DesignBuilder, which allow the integration of building information modeling (BIM), building energy modeling (BEM) and energy supply modeling (ESM) to optimize the energy design.
The results of commercial projects aimed at achieving nearly zero-energy building (nZEB) standards have informed the development of two energy concepts, both aiming to decrease dependency on district heating networks. These concepts encompass electrical and thermal concepts. In the electrical concept, the air-water heat pump (AWHP) and electric boiler demonstrated better energy efficiency compared to the thermal concept, which utilized a biomass boiler in conjunction with solar thermal collectors (STC) to mitigate the impact of coal-fired electricity. In addition to reducing energy dependence in the air handling unit (AHU), it is proposed to introduce a ground water-to-water heat pump (GWWHP), which is connected to the surface exchanger to capture heat leaks from central heating networks. A comparative analysis of installations without and with heating recovery unit (HRU) shows a fivefold reduction in electricity consumption for heating supply air. Solar technologies, including STC and photovoltaic (PV) panels, are integrated into each concept, but the limited use of STC makes a PV system the preferred option. The decisions made during the modeling process resulted in a fourfold reduction in the office building's average annual consumption compared to government requirements. Selection of energy efficient equipment and modeling led to nZEB classification for both concepts, achieving renewable energy system (RES) penetration rate from 16% to 33% of total consumption.
Economic analysis using the annuity method highlights the cost-effectiveness of rooftop PV systems compared to façade PV systems. In addition, wood pellets and solar heat help reduce costs in the thermal concept. The environmental analysis shows the significant reduction in carbon dioxide emissions achieved by the thermal concept, highlighting the importance of alternative energy sources for sustainable urban development.
The demand for heat energy is increasing worldwide and to achieve net zero
carbon emissions targets, more innovation is needed for heat production. Heat
pumps are considered a potential replacement for boilers and are currently in
high demand. The next approach is to optimize the use of heat pumps with
household PV production to avoid grid overloading due to running increased
demand by the heat pump. In this work, a Reinforcement Learning algorithm is
used in the MATLAB RL toolbox with an energy-building model built in MATLAB
Simulink Carnot. The energy building model uses a heat pump to charge thermal
storage, and a PV system is considered with a typical ON/OFF strategy. This work
shows how the RL toolbox has the potential to interact with this energy-building
model to optimize the heat pump with a PV system. All suggested agents by the
MATLAB RL toolbox are investigated with this building energy model (BEM), and
annual simulation is performed with a well-trained agent, which converges
during training. Two different models have been developed for heat pump
control. The first model is called the RL-based Heat Pump Controller, which is
designed to meet thermal targets only. The second model is called the PV-
optimized RL-based Heat Pump Controller, which not only meets thermal targets
but also considers the operation of the PV system with the heat pump. The
simulation results show that using the RL toolbox, the RL-based Heat Pump
Controller model has performed excellently. In the PV-optimized RL-based Heat
Pump Controller model, there is almost a 4.37% increase in PV self-consumption
compared to the typical control strategy, resulting in annual electricity savings
of almost 3.52 MWh. Some challenges of using the RL toolbox are also
highlighted with future recommendations, which mainly include computational
efforts.
This thesis is focused on investigating the different criteria, such as Wind Capacity Penetration, Wind Energy Penetration, Maximum Share of Wind Power, Short Circuit Ratio and Simultaneity Factor. The main idea is to determine these criteria application areas, particularly installed power limitations in a particular region, in terms of grid stability.
The passenger transport sector is undergoing a transition towards electric mobility to reduce CO2 emissions. One commonly mentioned challenge that could hinder the success of electric vehicles is the availability of public charging infrastructure.
This work focuses on optimizing public car infrastructure from both technical and economic perspectives, providing valuable insights for decision-makers and operators of charging infrastructure.
It begins with a general analysis of mobility behavior in Germany, followed by an examination of charging locations.
Subsequently, the stakeholders involved in public car charging infrastructure are identified, and their goals are used to construct a set of key performance indicators (KPIs). These KPIs enable a comprehensive assessment of public car charging infrastructure.
The identified KPIs, including Economic Efficiency, Utilization, and Usability, are then applied to an exemplary set of public charging points, showcasing the practicality of these metrics, and offering valuable insights into their current situation.
The findings from the application of the KPI set, such as the critical economic situation of the assessed public charging infrastructure, are integrated with potential improvement opportunities and concrete measures to achieve the set goals.
The work emphasizes the importance of charging demand and utilization rate as key factors for the success of the evaluated charging stations, while also highlighting various other aspects that can enhance the performance of any public charging station.
Power systems globally are undergoing a significant transformation driven by the need to transition from fossil fuel-based systems to low-carbon and renewable energy sources. Increasing distribution energy resources penetration has led to the development of local generation and consumption ideas and, consequently, the emergence of the microgrid concept. However, the displacement of traditional power plants by distributed energy resources, especially in low voltage grids, poses new challenges for distribution grids’ operation, such as voltage control. The reactive power support capability of distributed energy resources, one of the microgrid components, makes them a potentially useful source for voltage issues. However, this support should be allowed within the framework permitted by regulations.
Although the Brazilian power system is mainly based on renewable energy sources, Brazilian legislation does not support the potential service capability of distributed energy resources. Moreover, the absence of an ancillary services market and the non-remuneration of ancillary services are the main reasons for distributed energy resources and microgrids not participating in such services.
This thesis proposes developing two business models for a non-isolated microgrid in Brazil, one that considers regulations and one that can be described as innovative by not considering regulations. The business model has been developed with a reactive energy compensation approach in which PV inverters are used. Furthermore, two different remuneration mechanisms have been proposed for the innovative business model. The microgrid where the developed business models are implemented is modelled and simulated in Open Distribution System Simulator with IEEE 13-node test feeder. Since the simulated microgrid does not have any voltage issues, sensitivity analysis is performed to be able to provide more accurate results. The sensitivity analysis results show that the proposed remuneration mechanism can motivate the microgrid to provide ancillary services, resulting in a profit for the microgrid and mitigating voltage problems of the distribution grid.
The further expansion of decentralized renewable energy sources and ramp-up in electric mobility and heat pumps triggers the need for traditional grid reinforcement measures. To effectively address the growing demand, it is crucial to simultaneously assess numerous options to generate technically optimal and economically feasible solutions. Therefore, new traditional grid reinforcement measures are introduced to the grid planning tool, eDisGo, and grid reinforcement simulations are conducted on high-resolution synthetic grid models representing the German grids for the investigations. Firstly, one scenario representing the future state of the German grid and six synthetically generated medium voltage grids, including underlying low voltage grids, are chosen. After grid issues are determined by respecting voltage and loading limits with power flow analyses based on the selected scenario, the existing and new measures are applied to the grids as a group or individually to solve the issues. Subsequently, with the results obtained for the MV and LV grid levels, the changes in the grids are analysed, and the extent to which the employed measures provide improvements. Lastly, as a result of the analyses, considering the grid reinforcement costs of each measure or measure group, the optimal solution for each grid characteristic is presented. In grids with highly loaded long feeders and a high number of feeders, reinforcements for LV grids with an additional MV/LV substation can offer the most suitable solution in terms of cost and improvement ratings. Splitting the feeders at a particular point provides cost-efficient solutions in reinforcing critical voltage deviations in MV and LV grids. In the reinforcement of overloading issues, the most optimal solutions cost- and improvement-wise is generally adding-line-based measures if the feeders are not long and comprised of highly overloaded lines. Optimization of switching unit in medium voltage rings conducted based on the loading of the feeders; although it is not a suitable solution in every case in terms of cost and improvement, costs can be kept at a lower priority since it is a vital reinforcement measure in terms of ensuring supply reliability in the rings.
In response to the rising environmental concerns, emission-free ferries, particularly hybrid hydrogen fuel cell and electric battery (HFC-EB) ferries have been considered a promising alternative to conventional ones with the potential to achieve efficient emissions reduction. However, their widespread adoption in the maritime industry is still limited due to numerous obstacles, including the lack of the required infrastructure to support them and the absence of regulatory frameworks such as refueling protocols designed for ferries. Currently, the design of hybrid ferries’ storage systems is driven solely by their requirements and focuses only on the optimization of the ferry’s operational side using several approaches, such as energy management systems (EMS). In regards to this, the present work considers the infrastructure dimension, such that a proposal of a hydrogen refueling protocol for ferries has been first developed based on the SAE J2601 standard designed particularly for light-duty vehicles. Further to this, two simplified models of a hydrogen refueling station (HRS) and a power charging station (PCS) infrastructures have been developed in Dymola/Modelica and later used to conduct the optimization investigations of a selected ferry case study regarding the infrastructure in a holistic approach. The energy split design between hydrogen and electricity was studied along with other parameters that impact the infrastructure design to be optimized regarding the infrastructure holistically by running various simulations. The sensitivity analysis results of these investigations’ simulations show the significant impact of infrastructure consideration when designing a hybrid ferry. In addition, it has been demonstrated that immense potential benefits can be harvested from the infrastructure perspective in terms of efficiency and cost effectiveness, including savings of power losses, cooling energy, storage system volume on board the ferry, and operational costs of both the ferry and infrastructure. Finally, by considering all the findings in an integrated and interconnected way, stakeholders of the maritime transportation sector, including ferry owners and operators and infrastructure providers, can identify the optimum split design of the hybrid storage system in a holistic approach regarding the infrastructure following the methodology for optimization developed
throughout this work.
Keywords: Hydrogen fuel cell/electric battery ferry, hydrogen refueling protocol for ferries, storage system design, optimization methodology, infrastructure, charging, refueling, simulation
The main objective of the thesis is to develop the simulation model of the refrigerant cycle in full operation mode by MATLAB Simscape and validate the model with the measurement data from the existing heat pump prototype. It starts with introducing the fundamentals of heat pumps, including explaining the refrigerant cycle, coefficient of performance, and performance factor. Then review the application of different types of heat pumps, refrigerants, and heat exchangers from the literature. For modeling the heat pump, two methods are used in the work. The compressor and the expansion valve are using the first method which is modeled by the datasheet and the measurement data; the condenser and the evaporator are utilizing another method for modeling which is by the MATLAB tool parameter estimator. The thesis has explained the detailed method of modeling the heat pump. After completing the model, it has been run and validated by the measurement data from the prototype. The model can operate properly and the properties of the simulation model are reasonable. But for validating the model which means compared to the measurement data from the prototype, there are still some flaws or errors, especially for the evaporator model. They will be discussed in the work. Overall, the thesis still provides a promising method for developing the simulation model of a heat pump.
Large PV power plant investments have accelerated in the last decade due to economic and political developments in the world. These investments have led to the technological development and maturity of all components used in a large PV power plant. However, large PV power plants still face various failures at the system and component levels. Detecting these failures instantly or even in advance will minimize the operation and maintenance costs and maximize the system reliability and safety of large PV power plants. As SCADA is still the most mature control and monitoring technology in the industry, PV power plant designers and operators can benefit from its functionalities to develop predictive maintenance strategies and control the large PV power plant built in a wide area. The thesis aims to conduct research on available SCADA infrastructure technologies for large PV power plants and compare them in a technical aspect to understand their effect on developing predictive maintenance strategies.
Developing predictive maintenance strategies for large PV power plants depends on the correct, coherent, and reliable data provided by the SCADA system. All the necessary SCADA components that generate and transmit the operational data are identified. Standard SCADA communication protocols and topologies are compared in terms of their applicability to large PV power plants and their positive contribution to developing predictive maintenance strategies. Key performance indicators are identified for generating the actual operational trends, which are compared to expected or designed operating trends in the scope of predictive maintenance strategy. To improve the reliability and safety of the SCADA system, cyber-attack risk mitigation methods and redundancy instruments are presented.
By considering all the findings and results of the multifaceted comparisons, a SCADA infrastructure system is designed as a case study to improve the effectiveness of the predictive maintenance strategy of a gold mine PV + BESS hybrid power plant in Burkina Faso.
Convective losses inside a cavity of a novel insulating glass flat-plate solar thermal collector
(2022)
Large-scale solar thermal district heating plants are considered to serve as a renewable alternative in European District Heating systems but their execution imposes widely-considered demand fluctuations and initial cost challenges. Consequently, A novel Insulated glass flat plate solar thermal collector (IGFPC) of low manufacturing cost is introduced to the industry, nevertheless, more research is needed on the collector’s convective heat losses and efficiency. This research focuses on the numerical study of the convective heat losses inside the cavity of the novel IGFPC. The review of other literature concludes the inability to describe the convective losses inside the cavity using other researchers’ correlations due to its large aspect ratio and high operating Rayleigh range so a computational fluid dynamics (CFD) simulation using the Finite Elements Method (FEM) is performed. The research investigates the optimum simulation settings and the optimum mesh size to solve the CFD simulation, in addition to, the governing correlations representing the heat transfer regime inside the cavity. The cavity inclination is studied at angles 0, 15, 30, 45, and 60 degrees heated from below, and Rayleigh numbers ranging from 10^3 to 10^6. It is concluded that the Reynolds stress model (RSM) is the most accurate turbulent model to represent turbulent flow inside the cavity and its results are comparable to other results from the literature. In comparison with the literature review, the simulation results show low convective heat losses at Ra < Ra critical and high convective heat losses at Ra > Ra critical. It is also noted that at a lower Rayleigh number, the cavity experience edge rolls at lower inclination angles and cell rolls at higher inclination angles. Finally, a correlation in the Nusselt Rayleigh domain is derived to be used for numerically calculating overall losses and efficiency for cavities with a high aspect ratio.
Keywords: solar district heating, convective heat losses, solar thermal collector, insulated glass flat-plate collector, natural convection, computational fluid dynamics, Nusselt / Rayleigh correlations, Rayleigh number, rectangular cavity, cavity inclination angle
The Distribution Network (DN) in Europe and North America today is witnessing a paradigm shift in operation from a conventional passive system where a top to bottom active and reactive power flow is maintained with a low level of monitoring to an active system where the power flow has become bi-directional with the influx of Distributed Generators (rooftop solar photovoltaic units, wind generating units, etc) in the low voltage (LV) and medium voltage (MV) networks. This implementation of DGs poses power quality problems as it causes stress on the existing voltage regulating strategy in the DN. To tackle this issue, utilities in both regions are integrating smart devices for controlling and monitoring the DN to guarantee power quality for their customers.
The initial part of this paper focuses on individually and collectively studying the factors that determine how a network responds to voltage control. After which the impact and response of various load types and composition to voltage control were analysed. The difference between the MV and LV grid topology of the two regions was also highlighted. The second part of the project concentrates on the conventional and improved control devices implemented by utilities for achieving voltage stability. A case study of a representative network from both regions highlighting the advantages and challenges faced by adopting automated voltage regulation (AVR) was also carried out in this paper. In addition, the historical failure of the grids of both regions was examined to identify how the grid will react when a voltage control tool fails intending to suggest possible solutions.
The battery energy storage system is one of the systems that can support the use of renewable energy. The battery system is used to store electric energy, and it provides flexibility when energy is required at a certain time. It is essential to adjust the temperature of the battery cells in order to maintain better performance, a long lifespan, and great safety in the battery system. As a result, it is necessary to have a proper and better designed thermal management system that can keep the battery cells within the required temperature range when the battery systems are in operation. Heat transfer is a considerable phenomenon that is connected with the battery energy storage system. In general, temperature is the most important variable in heat transfer, which occurs when heat moves from a higher temperature zone to a lower temperature region. Heat transfer within the medium can be described by conduction, convection, and radiation. This thesis describes a study that was undertaken to tackle heat convection based thermal problems inside the battery module and the battery system rack. The battery module and the battery system rack are employed in energy market operations and renewable energy storage. Thermal heat convection based on heat transfer and fluid (air) flow inside the battery module and the battery system rack is designed in SolidWorks software and then simulated with FloEFD software for CFD simulations. SolidWorks and FloEFD software are described in detail, including heat transfer and fluid flow, internal and external air-forced boundaries, and physics connections. In addition, the process flow of 3D model design using SolidWorks software and the simulation process using FloEFD software explains the different possible initial conditions, boundary conditions, and necessary inputs. This thesis report also describes in detail the available strategies and approaches to addressing this thermal problem using FloEFD software. The simulation results are presented at the end of the thesis report in the form of a simulation and analysed solution for the battery system cooling.
The world is moving forward, and its energy need is also increasing daily. Currently, a significant amount of this energy comes from a finite resource called fossil fuels. The biggest problem with this resource is the high amount of carbon emissions, which has an adverse impact on the environment in the form of global warming, greenhouse gases, ozone layer depletion, etc. This in turn could lead to dangerous consequences for the planet and the ecosystems. Governments across the globe are getting serious and taking big resolutions toward green energy, but the set targets are big and still far away. High motivation and strong will among the top leaders are necessary to achieve the target of using green energy for most of the world's energy demands. This must be met with prompt actions and a decisive approach. Hydrogen, the resource available abundantly in the atmosphere, can be the biggest hope towards this target. Studies have shown that hydrogen can take the green energy revolution a long way if produced on a large scale.
A renewed and widespread hydrogen momentum is growing in the energy market. The last years have witnessed a substantial increase in demand for hydrogen, including several countries introducing and developing new hydrogen national strategies and many private companies leaning toward investing in hydrogen-related projects. Green hydrogen's environment-friendly and versatility will lead the world toward a hydrogen economy.
Though there are increased investments in the technological advancement in green hydrogen, there exist many unresolved issues related to technical and infrastructural challenges. Nevertheless, a clean and renewable hydrogen economy will not only fight climate change but also offers a comprehensive infrastructure for new opportunities in terms of jobs and employment. Hydrogen may play a crucial role in restructuring the international alliances and conflicts regarding global transformation and decarbonisation of the energy market. By 2050, hydrogen can supply up to 24% of the world's energy needs
This paper is inclined towards a quantitative assessment of the hybrid (with and without battery storage) green hydrogen production system in terms of working and financial feasibility.
Despite having the world's fastest-growing population, Sub-Saharan Africa has the lowest electrification rates, indicating the urgent need for improved energy infrastructure. While all its member countries have, since 2016, bid to abide and follow through with the 7th sustainable development goal, among others, electricity access remains below targeted rates. Research and implementation plans have extensively focused and relied on grid extension into semi-urban regions while neglecting rural settlements. Low population densities of rural regions discourage many electrification approaches. Sub-Saharan Africa, however, records a drop in the price of renewable power products and penetration of mini-grid technology into some of its rural regions. This brings forth the potential in assessing whether the integration of existing micro-grids in rural regions is a feasible electrification approach. To link energy demand and supply from the existing micro-grids, this thesis quantitatively audits energy consumption and develops load profiles for Uutsathima village and its distinguished settlement categories using MATLAB algorithms. The resulting load profiles are fed into PVsyst to size mini-grids per case scenario and compare the existing micro-grid capacity to recommend the best solutions when considering micro-grid integration. Results show that the existing 50% of excess unused energy generated can potentially electrify business settlements of Uutsathima and electrification of households can be attained by implementation of a new mini-grid. Findings validate and define conditions for the feasibility of micro-grid integration dependent on generation capacities as well population/ settlement density.
Since more and more large conventional power plants, based on direct-coupled synchronous generators (SGs), will be phased out in the future, frequency stability must be guaranteed. Consequently, grid-forming inverters are needed to ensure the system stability of the future grid. In the joint research project “VerbundnetzStabil”, conducted by Fraunhofer ISE and its partners, the stability of a grid system with a high penetration of inverter-based renewable energy sources (RES) is investigated. This master thesis aims to analyze the response of the inverter simulation model, designed by Fraunhofer ISE, facing different events, whether it reacts as a synchronous machine and helps to maintain the stability in the network, and at the same time analyze the cross-coupling effect between the active and reactive power of the controller. For this purpose, the test models were designed in DIgSILENT PowerFactory to get RMS and EMT results. The results were compared with experimental results obtained in the multimegawatt Lab from Fraunhofer ISE to improve the inverter response.
Keywords: droop control, grid forming inverters, cross-coupling effect, inverter control, power system stability, inverter testing, inverter parameters
This thesis talks about the latest EU grid codes and compares various EU countries based on their national grid codes adopted from the EU framework. Inverter existing and future technologies and their functionalities are discussed in detail. A MATLAB/Simulink model of the inverter and a DigSILENT model of a real plant has been made for simulation purpose and to verify various functionalities and requirements from the inverter.
This study aims to compose a coupling interface between the agent-based model ‘AgentHomeID' and the energy system model ‘SCOPE-Path' to determine building heat supply systems and then evaluate the impact of building aggregations and decentralized heat limits changes on ‘SCOPE-Path' model output and computation effort. First, a coupling interface based on the output of the ‘AgentHomeID' was developed, and then it was used as an input to the existing path optimization model ‘SCOPE-Path.' The first model defined as reference model holds the highest number of building classes and narrow space on decentralized heat limits. Three more different models were derived from the detailed reference model. A reduced number of ten and eight residential building classes were applied to the second and third models. The fourth model derived from the reference model specified a wide range of decentralized heat limits with a similar number of building classes as in the reference model.
Finally, the three different models were optimally simulated for the same scenario, given that the third model with eight residential building classes failed to be optimized, and the accuracy of the outputs and computational effort of the optimized models were evaluated. The reference model required the longest computation time. The second model with ten residential building classes showed the most significant reduction in computational effort with varying degrees of accuracy loss. The fourth model with a wide range of decentralized heat limits reduced computational efforts substantially with varying degrees of accuracy loss in outputs.
The crucial drawback of this study is the exclusion of solar thermal from the second, third and fourth models to simulate optimally. This approach barred the observation to determine the definite impacts of the building aggregation and wide range of decentralized heat limits distinctly on the ‘SCOPE-Path’ model's output and computation effort. Furthermore, it was insufficient to identify the effects of further building aggregation on ‘SCOPE-Path’ due to the non-optimized third model with eight residential building classes.
Photovoltaic facade, a dual functional product which is an elemental component of the building envelope has the capability to generate clean electricity. It also has the capacity to meet the local energy demand and provide protection from external environment. This research is focused on distributed electricity generation application and economic feasibility of vertical window PV facades, an element of building-integrated PV. The objective of the study is to investigate the energy potential that can be recovered from window-integrated organic photovoltaics (OPV), a technology that allows solar modules to be (semi-)transparent. A brief description of the regulations, standards and laws that monitor the development rate of PV is reviewed. A simulation model using MATLAB is built to determine the irradiation potential and the energy harvest of OPV modules in Nuremberg, Germany. The optimum orientation angle of the facade is found based on the azimuth angles. For the area of Nuremberg, a vertical PV system yields the maximum energy harvest when being a southwest-oriented. Based on a statistical distribution of buildings and facade orientations considered all over Germany, the total energy that can be harnessed from window PV facades is estimated to be about 23 TWh per year and the LCOE is calculated to be 69,2 c.€/kWh with state-of-art OPV modules with a lifetime of 5 years. Subsequent development of the organic photovoltaic technology with respect to efficiency and lifetime has the ability to yield 100% transparent window PVs with an overall energy harvesting potential of about 80 TWh per year at a cost of 6 c.€/kWh, if all suitable windows in Germany are equipped with such modules.