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The environmental restrictions on consuming fossil fuel energy indefinitely and the increasing need for energy in human society have created a necessity to improve energy efficiency in all sectors of demand including buildings. Consequently, research interest has been provoked to enhance the energy performance of building facades. This research investigates a multifunction and energy-efficient glazing system in which both electrical energy and thermal energy are collected from the glazing while providing thermal resistance and intelligent daylighting. Innovations such as Vacuum Glazing (VG) with its characteristics related to high thermal resistance have been investigated solus or combined with other innovations in intelligent energy-efficient facades. The vacuum-included building facades aim to reduce heat transfer through the glazing and potentially add an extra energy-related function to the system. Vacuum water flow glazing, vacuum electrochromic glazing, vacuum Suspended Particle Device (SPD) glazing, vacuum Photovoltaic (PV) glazing, and evacuated flat plate solar collectors are examples of multifunction vacuum-included building façades. Photovoltaic/Thermal (PV/T) is an innovation in solar energy technology that while absorbing the wasted heat from the PV phenomenon of the PV cells aims to increase output electricity as well as harvest benign thermal energy. Also, Semi-Transparet Photovoltaic (STPV) facades in which PV cells are placed between glass pane layers were introduced and widely investigated to control daylight and solar heat gain, also, to generate small-scale electric energy from the large fenestrated surface in zero/low energy buildings. In this research, the integration of VG, PV/T, and Concentrating Photovoltaic Glazing (CoPVG), which is an STPV glazing concept, has been investigated in the aspect of energy performance. This research introduces an enhanced version of the CoPVG device. The original CoPVG system was designed as a seasonal glazing, that concentrates sunlight onto the focus of the lens to exploit electricity generation during summer. Whilst, in winter, the system transmits light for indoor daylighting purposes. The newly developed version of the glazing, entitled Concentrating Photovoltaic/Thermal Evacuated Glazing (CoPVTEG) is a Semi-Transparent Photovoltaic/Thermal (STPV/T) glazing which is capable of simultaneously harvesting thermal energy and electricity. In addition, VG has been integrated into the device to enhance its thermal resistance providing a low U-value semi-transparent glazing. In advance, an experiment was conducted to test the optical efficiency of the lenses of CoPVG concept. The experimental results were compared with an analytical model developed at Ulster University. As discovered that the model predicts the optical performance of the lenses reliably, the model is then used to create a visual representation of the glazing's annual optical performance, demonstrating how the glazing responds to changes in the sun's position in the sky throughout the year. As an example, the results indicate that utilising the lenses in glazing towards the south in Belfast leads to a shift in its performance from room lighting to shading on April 1st, and vice versa on September 15th. The analyses, also, showed that utilizing the CoPVG lenses can potentially enhance the electrical output power of the glazing ranging between 5% and 8% and from 46% up to 52% during winter and summer, respectively, when that is compared with traditional STPV glazing with the same opaque area percentage. A finite element method was employed to simulate the glazing computationally, aiming to determine the interaction of the device with the vacuum gap. The developed model was validated by conducting experiments including fabricating a full-size prototype, designing and constructing an experimentation rig, and performing tests. Two different configurations were considered for simulation. The VG can be positioned in either an outward-facing manner, known as disposition A, or an inward-facing manner, known as disposition B. These dispositions were analysed computationally to determine the thermal and electrical output powers of the device in Belfast, UK. It was found that locating the VG inside, i.e., disposition B, potentially doubled the output electrical power compared to the other configuration, ranging from 63.32 W/m2 to 92.56 W/m2 and from 36.03 W/m2 to 43.88 W/m2 at noon throughout the year for disposition B and A, respectively. However, the thermal harvesting potential of disposition A is higher than disposition B. In this case, the device potentially generates from 216.46 W/m2 to 406.20 W/m2 thermal power at noon throughout the year. While the potential will be reduced from 163.54 W/m2 to 396.11 W/m2 in disposition B. Disposition A is more advantageous for cold-dominant climate zones while disposition B is the suggestion for a temperate climate zone similar to the studied case.

The building sector is responsible for more than one-third of global energy consumption. With increasing global population, the demand for energy efficiency buildings and on-site electricity production is rising. Building integrated photovoltaics (BIPV) is one of the most promising contributors to net-zero energy buildings, while also increasing the aesthetic value of the built environment. Among all the transparent solar cells, dye-sensitised solar cells (DSSCs) have low production cost, semi-transparency nature and a range of colours for building design. This thesis presents an overview of the current energy scenario and future prospects, state-of-the-art of photovoltaic technologies and the challenges in commercialising new generation solar cells. The first approach here is to find an efficient and low-cost alternative photoanode, sensitiser and counter electrode for DSSC. The tested materials are high surface area mesoporous TiO2, new ruthenium complex (m-HRD-1) sensitiser and Jet nebulizer spray coated CZTS. All the obtained results are compared with the commercial materials. Secondly, semi-transparent DSSCs are fabricated with different transparencies and their colour properties such as correlated colour temperature and colour rendering index are evaluated. Moreover, glazing properties and daylight glare analysis are studied to assess the possibility of adopting semi-transparent DSSCs into building architectures. Finally, a low solar concentrator is placed on the transparent-DSSCs to enhance their photovoltaic performance. The internal charge transfer mechanism of the DSSCs is also studied to understand the impact of the concentrated light. Furthermore, the performance of the concentrator coupled devices under different light intensities is studied. The results presented here provide a fertile base for further investigation, which will focus on improving the performance of all the new generation low cost solar cells using optical elements with new designs. The target is to improve the performance and stability of the transparent solar cell devices and use them as BIPV materials to overcome the challenges of the increasing energy demand.

The ongoing transformation of the energy system along a more sustainable trajectory requires advancements in a range of technological fields, as well as active involvement of different societal groups. Integration of photovoltaic (PV) systems in the built environment in particular is expected to play a crucial long-term role in the deployment of renewable energy technologies in urban areas, demanding the successful cooperation of planners, architects, engineers, scientists and users. The realisation of that technological change will require innovation at both an individual (within firms and organisations) and a collective (sector) level, giving rise to systemic approaches for its characterisation and analysis of its drivers. This study investigates the processes that either accelerate or hinder the development and diffusion of Building-Integrated PV (BIPV) applications into the market. Affected by developments in both the renewable energy and construction industries, the BIPV innovation system is a multi-sectoral case that has been explored only partially up to now. Acknowledging the fact that drivers of innovation span the globalised BIPV supply chain, this research adopts both an international and a national spatial perspective focusing on the UK. The analysis is based on a novel analytical framework which was developed in order to capture innovation dynamics at different levels, including technological advancements within firms, competition and synergy with other emerging and established innovation systems and pressures from the wider socio-economic configuration. This hybrid functional framework was conceived by combining elements from three academic strands: Technological Innovation Systems, the Multi-Level Perspective and Business Studies. The empirical research is based on various methods, including desktop research, semi-structured interviews and in-depth firm-level case studies. A thorough market assessment provides the techno-economic background for the research. The hybrid framework is used as a guide throughout the empirical investigation and is also implemented in the analytical part of the study to organise and interpret the findings, in order to assess the overall functionality of the innovation system. The analysis has underlined a range of processes that affect the development and diffusion of BIPV applications including inherent technological characteristics, societal factors and wider transitions within the energy and construction sectors. Future approaches for the assessment and governance of BIPV innovation will need to address its hybrid character and disruptiveness with regards to incumbent configurations, in order to appreciate its significance over the short and long term. Methodological and conceptual findings show that the combination of insights from different analytical perspectives offers a broader understanding of the processes affecting innovation dynamics in emerging technologies. Different approaches can be used in tandem to overcome methodological weaknesses, provide different analytical perspectives and assess the performance of complex innovation systems, which may span multiple countries and sectors. By better reflecting complexities, tensions and synergies, the framework developed here offers a promising way forward for the analysis of emerging sustainable technologies.

Buildings both commercial and residential are the largest consumers of electricity. Integrating Photovoltaic technology in building architecture or Building Integrated Photovoltaics (BIPV) provides an effective means for meeting this huge energy demands and provides an energy hub at the place of its immediate requirement. However, this technology is challenged with problems like low efficiency and high cost. An effective way of improving the solar cell efficiency and reducing the cost of photovoltaic systems is either by reducing solar cell manufacturing cost or illuminating the solar cells with a higher light intensity than is naturally available by the use of optical concentrators which is also known as Concentrating Photovoltaic (CPV) technology. Integrating this technology in the architecture is referred as Building integrated Concentrating Photovoltaics (BICPV). This thesis presents a detailed performance analysis of different designs used as BICPV systems and proposes further advancements necessary for improving the system design and minimizing losses. The systems under study include a Dielectric Asymmetric Compound Parabolic Concentrator (DiACPC) designed for 2.8×, a three-dimensional Cross compound parabolic concentrator (3DCCPC) designed for 3.6× and a Square Elliptical Hyperbolic (SEH) concentrator designed for 6×. A detailed analysis procedure is presented showcasing the optical, electrical, thermal and overall analysis of these systems. A particular issue for CPV technology is the non-uniformity of the incident flux which tends to cause hot spots, current mismatch and reduce the overall efficiency of the system. Emphasis is placed on modelling the effects of non-uniformity while evaluating the performance of these systems. The optical analysis of the concentrators is carried out using ray tracing and finite element methods are employed to determine electrical and thermal performance of the system. Based on the optical analysis, the outgoing flux from the concentrators is predicted for different incident angles for each of the concentrators. A finite element model for the solar cell was developed to evaluate its electrical performance using the outputs obtained from the optical analysis. The model can also be applied for the optimization of the front grid pattern of Si Solar cells. The model is further coupled within the thermal analysis of the system, where the temperature of the solar cell is predicted under operating conditions and used to evaluate the overall performance under steady state conditions. During the analysis of the DiACPC it was found that the maximum cell temperature reached was 349.5 K under an incident solar radiation of 1000 W/m2. Results from the study carried on the 3DCCPC showed that a maximum cell temperature of 332 K is reached under normal incidence, this tends to bring down the overall power production by 14.6%. In the case of the SEH based system a maximum temperature of 319 K was observed on the solar cell surface under normal incidence. An average drop of 11.7% was found making the effective power ratio of the system 3.4. The non-uniformity introduced due to the concentrator profile causes hotspots in the BICPV system. The non-uniformity was found to reduce the efficiency of the solar cell in the range of 0.5-1 % in all the three studies. The overall performance can be improved by addressing losses occurring within different components of the system. It was found that optical losses occurred at the interface region formed due to the encapsulant spillage along the edges of the concentrator. Using a reflective film along the edge of the concentrating element was found to improve the optical efficiency of the system. Case studies highlighting the improvement are presented. A reflective film was attached along the interface region of the concentrator and the encapsulant. In the case of a DiACPC, an increase of 6% could be seen in the overall power production. Similar case study was performed for a 3DCCPC and a maximum of 6.7% was seen in the power output. To further improve the system performance a new design incorporating conjugate reflective-refractive device was evaluated. The device benefits from high optical efficiency due to the reflection and greater acceptance angle due to refraction. Finally, recommendations are made for development of a new generation of designs to be used in BiCPV applications. Efforts are made towards improving the overall performance and reducing the non-uniformity of the concentrated illumination.

In recent years, new construction has witnessed a rise in the adoption of building-integrated photovoltaics (BIPV) and smart glazing strategies, however, costs have remained one of the concerns and create barriers to implementation. Considering Austin’s population is predicted to double by 2050, this study utilized the DOE high-rise apartment stock commercial building model to analyze both the annual cost and energy savings of employing PV and smart glazing technologies. Applications of electrochromic glass (EC) in isolation (that is, without BIPV) resulted in an average 27% reduction of building energy use intensity (EUI), while applications of mono-crystalline silicon (mono-Si) panels and dye-sensitized cell (DSSC) facade panels with EC in isolation (without BIPV) yielded 38.9% and 29.7 % reductions, respectively. Notably, considering both EC and BIPVs resulted in an average decrease in building EUI of 73% and 65% for Mono-Si and DSSC panels, respectively. In terms of costs, dye-sensitized cells with electrochromic glass proved to be “twice as good” (in terms of the payback period decreasing by half, and consequently the cost-benefit ratio improving by a factor of two), when compared to mono-crystalline silicon cells with EC glass. Currently, less than 1% of buildings in Austin are net-zero, while Austin’s 2021 Climate Equity Plan seeks to achieve a 25% reduction in emissions for existing buildings, followed by a goal to achieve net-zero operational carbon emissions for all new constructions by 2030. As a result, this study can aid the strategy for reduction in emissions and advance Austin closer to its goal of net-zero emissions by 2040.

Abstract: A Luminescent Solar Concentrator (LSC) is a device that consists of a transparent plate with photovoltaic (PV) cells connected to one or more sides. The transparent plate functions as a waveguide and contains luminescent particles, such as organic dyes or quantum dots. The luminescent particles absorb sunlight and part of the re-emitted rays is guided towards the edges of the LSC by total internal reflection, where light is converted to electrical energy from the PV cells. The efficiency of the received sunlight directed to the edges of the LSC is determined by the size of the waveguide and the luminescent particles. This thesis outlined the important characteristics of the LSC, such that we can optimize its optical efficiency for best performance. Here, red-dye (Lumogen F 305) and silicon quantum dots (Si-QDs) were studied, and their application to the LSC was simulated by modifying the physics of the photon interaction. Initially, a red-dye-based LSC model was simulated in ray-tracing software. The LSC simulation results are compared to existing experimental measurements. After the validation of results, the ray-tracing method was extended to the silicon quantum dot-based thin-film LSC model. Quantum dots were found to be a good luminescent particles for LSCs since they have a large Stokes shift, which reduces the re-absorption loss. Later, a silicon quantum dot thin-film LSC model was simulated, in which, a ray-tracing simulation model is developed to study the optical efficiency of a given LSC structure. The model consists of a low-iron glass with a copolymer film known as Poly (butyl methacrylate-co-methyl methacrylate) and silicon quantum dots embedded in it. The quantum dot characteristics were changed in this model, and the optical efficiencies were recorded. The models were used to present different parameter studies of the LSC to optimize performance.

In his book Ritual House, Ralph Knowles states, "The houses we inhabit, the cities surrounding our houses, even the clothes we wear - all are shelters we erect against the elements. But they are also manifestations of ancient rituals, developed in response to nature's rhythms" (2006). Implicit within this quote is the importance of nature's rhythms in our lives, particularly those related to the movement of the sun. Many built environments have no connection to the exterior. Those who work in these spaces are disconnected from these natural rhythms and often experience detrimental physiological effects. However, technology has the potential to reintroduce aspects of natural rhythms into built environments. This research crossed disciplinary boundaries separating architecture, engineering, psychology, and building science during the design of an architectural intervention for an interior workspace known as the Sandbox, at Virginia Tech. The design proposal includes skylights that combine Photovoltaic-integrated glazing with LED lighting to create conditions that stimulate the occupants while connecting inside to out. To reestablish a connection to natural rhythms the BIPV energy monitoring is used during the day to record variations in solar radiation which at night are played back through intensity and color variations of LED lighting. The effect of the LED lighting was compared with the sunlight entering through the skylights using quantitative analysis methods and qualitative visual comparison tools including time lapse photos and videos. The research merges architectural design, lighting technology and BIPV to demonstrate a proof-of-concept for the reintroduction of natural rhythms into built environments.

It is forecasted the human population will increase by 33% by 2050 and 70% by 2100. With exponential population growth there exists a global energy demand to power the lives of humans and the cities they dwell in. To meet this need it is imperative that society curbs its greenhouse gas emissions and resource consumption; clean energy is greatly needed. This requires major innovations in building technology, energy efficiency, power savings, recycling and renewable energy generation. This is paramount to sustaining natural resources and the human condition for future generations to continue into perpetuity. However daunting, this crisis gives rise to critical opportunities in the area of architectural design and resource augmentation. This D.Arch dissertation presents a technological building solution through an intrinsic application of nature and energy: The Sun and its light. The design development of a Building Integrated Photovoltaics (BIPV) awning system digitally retrofitted on a high-rise building in downtown Honolulu, Hawai’i will be assessed based its energy savings and power utilization methods. Measurements of this system will be in examining a methodology, which focuses on the duality of its active (photovoltaic) energy generation merged with its passive (shading) energy qualities. Investigation will focus on how to consolidate a merger for increased power potential in electrical energy performance, on-site energy savings, and progressive architectural design. The project looks at ten BIPV iterations, which use energy and daylight simulations, to judge the designs’ form and function. This is done to achieve a 1-to-10 BIPV factor, which balances certain qualitative and quantitative outlines for final implementation. From the research, design, data collection and energy simulations, it was discovered that in implementing the preferred BIPV façade retrofit, in downtown Honolulu, produced power savings in the magnitude of 7.8%, generated over 404k kWh/year and established a payback period of 4 years. Not only can BIPV design implementations provide for efficient cost dynamics but can also extend into future energy production and saving benefits. These aspects are crucial in providing a template for potential PV ubiquity and adoption within the built environment for better resource utilization and energy recycling in the 21st century.