The aim of the master’s thesis was to design heating, ventilation and cooling systems and to evaluate possibility of using renewable sources in case of a reconstructed two-storey family house. Air to water heat pump and floor system were designed to ensure both heating and cooling supply in the building. A heat recovery ventilation system was proposed. Gains of electrical energy from photovoltaic array were calculated and then possibility of coverage the heat pump consumption was evaluated. The thesis contains required calculations including building heat losses, heat gains, air exchange rates and the dimensioning of all mentioned systems. Technical drawing is also comprised.

To mitigate climate change and to achieve global carbon neutrality, the expansion of renewable energy sources is of paramount importance. In this context, photovoltaics (PV) are widely regarded as one of the most promising technologies to lead the transformation towards decarbonized energy systems. However, the manufacturing of PV systems is associated with initial greenhouse gas emissions linked to the procurement of PV components. Therefore, current research focuses on minimizing initial emissions to improve the overall environmental performance of PV systems. Since previous research suggests that conventional aluminum module frames contain a significant amount of embodied carbon, this study investigates a possible material substitution with wood as alternative frame material to lower the overall carbon footprint of PV modules.  To test the technical feasibility of PV modules with wooden frames, a proof of concept (POC) is conducted using wood types that exhibit necessary characteristics regarding their mechanical properties and durability. Guided by the finite element method and preliminary testing, a novel frame design is conceived, and PV modules with wooden frames are realized. The prototypes are put to extensive testing, in which the mechanical stability is examined, and weathering effects are investigated in an outdoor installation. Furthermore, a life cycle assessment (LCA) is carried out to quantify potential benefits of wooden compared to aluminum frames regarding their global warming potential and other environmental impact categories. Lastly, this study compares the economic performance of wooden PV module frames with aluminum frames and considers possible optimizations in the value chain of wooden frames. POC results show that PV modules with wooden frames - in line with industrial standards - are feasible, yet mechanical stability and durability vary depending on the type of wood and overall design. LCA results suggest that wooden frames exhibit invariably better environmental performance in all impact categories although a reduced module lifetime may impair the overall life cycle performance. In regard to cost efficiency, wooden frames are more costly than aluminum frames, yet financial incentives or subsidies may make low-carbon materials more competitive in the future. It can be concluded that wooden PV module frames may be a promising alternative to standard aluminum frames provided that the overall lifetime is identical. Thus, additional studies are required to analyze the long-term performance and to identify areas of application for modules with wooden frames, for instance in the building-integrated PV sector. Lastly, further research is needed to explore additional utilizations of wood in PV systems such as in ground and roof mounting structures.

Recently, decentralized household photovoltaic (PV) systems have become more affordable and there is a tendency to decrease subsidies for the PV excess electricity fed into the grid. Therefore, there is growing interest in methods to increase the self-consumption (SC), which is the part of the electricity produced by PV and directly consumed on buildings. It has been found that battery storage is an effective way to achieve this. When there is a heat pump system installed, thermal energy storage using the thermal mass of the building or hot water tanks, can also be used to increase the household self-sufficiency and minimize the final energy use. The main aim of this thesis is to develop operational control strategies for the heating system of a single-family house with an exhaust air heat pump, a photovoltaic system and energy storage. In order to accomplish this a detailed system model was developed in TRNSYS 17, which includes a six-zone building model and the heat pump control. Moreover, these control strategies include short-term weather and price forecast services.  Another objective is to evaluate the impact on the benefit of these control strategies in terms of energy use and economic performance for a wide range of boundary conditions (country/climate, electricity prices, occupancy and appliance loads).  Results show that the control using a forecast of dynamic electricity price in most locations leads to greater final energy savings than those due to the control using thermal storage for excess PV production. The exception is Sweden, where the result is the opposite. Moreover, the addition of battery storage leads to greater decreases in final energy than the use of the thermal storage (TH mode), which is limited to the thermal mass of the building and small hot water tank of the compact heat pump. As far as the impact of the advanced control (combined use of TH and PRICE) on cost savings is concerned, savings (up to 175 €) are possible in Spain and in Germany. The design of the TH and PRICE mode show low computational complexity that can be easily implemented in existing heat pump controllers. Additionally, the PRICE mode should have no capital and running cost for the end user while the TH mode might require an external electricity meter. Another yet implication with the TH mode is the need to activate the room thermostatic valve.

The master’s thesis deals with study the effectiveness of operation of photovoltaic power station. The theoretical part describes the legislative steps that led to the development of photovoltaic power stations, not only in Czech Republic but throughout Europe. The following is a review of the issue of photovoltaics, which includes the development of photovoltaics in the world, research of photovoltaic power stations in the Czech Republic and technology of photovoltaic power stations. At the end of the theoretical part is a list of methods to evaluate efficiency investments. The practical part includes a description of the selected photovoltaic station Zakřany 5.4 MWp, financial projection and economic evaluation of the real operation and there is also explicit evaluation of the economic efficiency of the project.. The comparison of the projection and the real operation and the possible negative influences affecting the power station are in conclusion.

The work deals with development and assembly of ultrasonic airflow measurement module for measurement of air flowing around photovoltaic panel. This system allows quantification of photovoltaic panel air cooling. The work contains development of sine wave generator, bridge amplifier and receiver with passive band pass filter, amplifier and comparator. It also deals with digital part realization. This digital part is formed by Renesas 78K0R microcontroller on demo board. The last part of this work contains testing of the whole system in aerodynamic tunnel and on photovoltaic panel installation.

This project solves the problem of cooling the photovoltaic cell. Solar cell was modeled according to a real model in SolidWorks, and subsequently created the model was simulated in SolidWorks Flow Simulation and Ansys Fluent. The use of both systems allow a comparison of their possibilities in the field of heat transfer and their suitability for the case. The conclusion summarizes the first results and outline further developments cooling design to optimize the performance of the solar cell.

The aim of this thesis is the design and building services systems in buildings with energy close to zero. The thesis 2 variants were designed heating and DHW. In variant 2 is considered with the photovoltaic system to generate electricity that is used up mainly in the building. It is part of the thesis experiment, whose aim was to monitor and evaluate the structure of electricity consumption in the residential unit.

The purpose of this dissertation is to design the dual-axis solar tracker carrying the concentrator photovoltaic panels. The preamble of the dissertation shortly examines a photovoltaic cells development up to concentrators and the common support structures of solar power plants. The second part focuses on the engineering process itself. It includes the choice of the variant that suits best the requirements, the calculations of wind load and design of the various joints. The conclusion part is devoted to the evaluation, economy analysis of the construction and proposals for improvements.

This diploma thesis deals with the accumulation of electrical energy in the scale of small house. The theoretical part describes the various ways of storing power. The practical part is devoted to the design and comparison of electrical energy accumulation for a particular house.

abstract: The emergence of perovskite and practical efficiency limit to silicon solar cells has opened door for perovskite and silicon based tandems with the possibility to achieve >30% efficiency. However, there are material and optical challenges that have to be overcome for the success of these tandems. In this work the aim is to understand and improve the light management issues in silicon and perovskite based tandems through comprehensive optical modeling and simulation of current state of the art tandems and by characterizing the optical properties of new top and bottom cell materials. Moreover, to propose practical solutions to mitigate some of the optical losses. Highest efficiency single-junction silicon and bottom silicon sub-cell in silicon based tandems employ monocrystalline silicon wafer textured with random pyramids. Therefore, the light trapping performance of random pyramids in silicon solar cells is established. An accurate three-dimensional height map of random pyramids is captured and ray-traced to record the angular distribution of light inside the wafer which shows random pyramids trap light as well as Lambertian scatterer. Second, the problem of front-surface reflectance common to all modules, planar solar cells and to silicon and perovskite based tandems is dealt. A nano-imprint lithography procedure is developed to fabricate polydimethylsiloxane (PDMS) scattering layer carrying random pyramids that effectively reduces the reflectance. Results show it increased the efficiency of planar semi-transparent perovskite solar cell by 10.6% relative. Next a detailed assessment of light-management in practical two-terminal perovskite/silicon and perovskite/perovskite tandems is performed to quantify reflectance, parasitic and light-trapping losses. For this first a methodology based on spectroscopic ellipsometry is developed to characterize new absorber materials employed in tandems. Characterized materials include wide-bandgap (CH3NH3I3, CsyFA1-yPb(BrxI1-x)3) and low-bandgap (Cs0.05FA0.5MA0.45(Pb0.5Sn0.5)I3) perovskites and wide-bandgap CdTe alloys (CdZnSeTe). Using this information rigorous optical modeling of two-terminal perovskite/silicon and perovskite/perovskite tandems with varying light management schemes is performed. Thus providing a guideline for further development. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019