India’s geographical location renders it with ample solar-energy potential ranging from 4-7 kWh/m2 daily and 2,300–3,200 sunshine hours annually. The diverse nature of human settlements (scattered low-rise to dense high-rise) in India is one of the unexplored avenues of harnessing solar energy through electricity generation using photovoltaic (PV) technology. Solar energy is a promising alternative that carries adequate potential to support the growing energy demands of India’s burgeoning population. A previous study estimates, by the year 2070, with 425 million households (of which utilizing only 20 %), about 90 TWh of electrical energy can be generated utilizing solar energy. PV is viable for onsite distributed (decentralized) power generation offering advantages of size and scale variability, modularity, relatively low maintenance and integration into buildings (no additional demand land). The application of solar PV technology as the building envelope viz., walls, façade, fenestration, roof and skylights is termed Building Integrated Photovoltaic (BIPV). Apart from generating electricity, PV has to also function as a building envelope, which makes BIPV systems unique. Even with a gradual rise in the number of BIPV installations across the world over the years, a common consensus on their evaluation has not yet been developed. Unlike PV in a ground mounted system, its application in buildings as an envelope has huge implications on both PV and building performance. The functions of PV as a building material translates well beyond electricity generation alone and would also have to look into various aspects like the thermal comfort, weather proofing, structural rigidity, natural lighting, thermal insulation, shading, noise protection safety and aesthetics. To integrate PV into a residential building successfully serving the purpose (given the low energy densities of PV and initial cost), would also mean considering factors like the buildings electricity requirement and economic viability. As many studies have revealed, 40% of electricity consumed in a building is utilized for maintaining indoor thermal comfort. Tropical regions, such as India, are generally characterized by high temperatures and humidity attributed to good sunlight, therefore, the externality considered for this study has been the impact of BIPV on the thermal comfort. Passive designs need to regulate the buildings solar exposure by integrating a combination of appropriate thermal massing, material selection, space orientation and natural ventilation. On the other hand, PV design primarily aims to maximize solar to generate maximum energy. The design requirements for climate-responsive building design may thus infringe upon those required for optimal PV performance. Regulating indoor thermal comfort in tropical regions poses a particular challenge under such conditions, as the indoor temperature is likely to be sensitive to external temperature variations. In addition, given current performance efficiencies for various PVs, high initial cost and space requirement, it is also crucial to ascertain PV’s ability to efficiently support buildings energy requirement. Thus, BIPV would require addressing, concurrently, design requirements for energy-efficient building performance, effective PV integration, and societal feasibility. A real time roof integrated BIPV system (5.25 kW) installed at the Center for Sustainable Technologies at the Indian Institute of Science, Bangalore has been studied for its PV and building thermal performance. The study aims at understanding a BIPV system (based on crystalline silicon) from the technical (climate-responsiveness and PV performance), social (energy requirement and energy efficiency) and economical (costs and benefits) grounds and identifies relevant factors to quantify performance of any BIPV system. A methodology for BIPV evaluation has been proposed (Integrability Methodology), especially for urban localities, which can also be adopted for various PV configurations, building typologies and climatic zones. In the process, a novel parameter (thermal comfort energy) to evaluate the thermal performance of naturally ventilated buildings combining climate-responsiveness and thermal comfort aspects has also been developed. An Integrability Index has also been devised, integrating various building performance factors, to evaluate and compare the performance of BIPV structures. The methodology has been applied to the 5.25 kW BIPV system and the index has been computed to be 0.17 (on a scale of 0 – 1). An insulated BIPV system (building applied photovoltaic system) has been found to be favorable for the climate of Bangalore than BIPV. BIPV systems have also been compared across three different climates (Bangalore, Shillong and Delhi) and given the consideration of the same system for comparison, the system in Delhi is predicted to have a higher Integrability than the other two systems. The current research work is a maiden effort, that aims at developing and testing a framework to evaluate BIPV systems comprising technical, social and economic factors.

The current work, through experimental and numerical investigations, analyses the process and cycle level deviations in engine response on fuelling multi-cylinder natural gas engines with producer gas. Producer gas is a low calorific value bio-derived alternative with composition of 19 ± 1% CO and H2, 2 ± 0.5 % CH4, 12 ± 1% CO2 and 46 ± 1% N2 and has thermo-physical properties significantly different from natural gas. Experimental investigations primarily address the energy balance (full cycle analysis) and in-cylinder response (process specific analysis) at various operating conditions covering naturally aspirated and turbocharged mode of operation with natural gas and producer gas. Numerical investigations are based on two thermodynamic scope mathematical models, a zero dimensional model (Wiebe function) and a quasi-dimensional model (propagating flame front heat release). A detailed diagnostic analysis on a six cylinder (E6) indicates, turbocharger mismatch, the first explicit impact of fuel thermo-physical property variation. Turbocharger matching and optimization resulted in a peak load of 72.8 kWe (BMEP 9.47) at a maximum brake torque ignition angles of 22 deg before TDC and compressor pressure ratio of 2.25. Engine energy distribution analysis indicates skewed energy balance with higher cooling load (in excess of 30%) as compared to fossil fuel operation. This is attributed to the presence of nearly 20% H2 which enhances the convective cooling through the higher thermal conductivity. Parametric variation of H2 fraction on a two cylinder engine (E2) with four different syngas compositions (mixture H2 varying from 7.1% to 14.2%) depicts enhanced cooling load from 33.5% to 37.7%. Process level comparison indicates significant deviations in the heat release profile compared to fossil fuels. It has been observed that with an increase in mixture hydrogen fraction (from 7.1% to 14.2%), the fast burn phase combustion duration reduces from 59.6% to 42.6% but the terminal stage duration increases from 25.5% to 48.9%. The enhanced cooling of the mixture (due to the presence of hydrogen), particularly in the vicinity of walls is argued to contribute towards the sluggish terminal phase combustion. Immediate implication of thermo-kinematic response variation is on the magnitude and sensitivity of combustion descriptors and the need for dependent control system calibration for producer gas fuelled operation is established. Descriptor analysis is extended to knocking pressure traces and a new simple methodology is proposed towards identifying the occurrence and regime of knock. Analysing the implications through numerical investigation, the influence of the altered thermo-kinematic response for producer gas fuelled operation impacts 0D simulations. Zero dimensional simulations fail with conventional coefficients requiring fuel specific coefficients. Based on fuel specific coefficients, the suitability of 0D model for the simulation of varying operating conditions ranging from naturally aspirated to turbo charged engines, compression ratios and different engine geometries is established. The analysis is extended to quasi-dimensional through the eddy entrainment and laminar burn up model. The choice of laminar flame speed and turbulent parameters is validated based on the assessment of the flame speed ratio (4.5 ± 0.5 for naturally aspirated operation, turbulent Reynolds number of 2500 ± 250 and 9.0 ± 1.0 for turbocharged operation, turbulent Reynolds number of 5250 ± 250). In the estimation of laminar flame speed, the limitation of GRIMech 3.0 mechanism for H2-CO-CH4 systems is explicitly established and GRIMech 2.11 is used to arrive at experimentally comparable results. In-cylinder engine simulation results covering parametric variation of load, ignition angle and mixture quality, for engine natural gas fuelled naturally aspirated operation and producer gas fuelled naturally aspirated and turbocharged after cooled are compared with experimental results. The quasi dimensional analysis is extended to simulate end gas auto-ignition and is validated by using experimental manifold conditions for turbocharged operation for which knock has been observed. Extending the model to a Waukesha cooperative fuels research engine, motor methane number of 110 is reported for standard composition producer gas. The use of quasi dimensional models with end gas reaction kinetics enabled for knock rating of fuels represents first of its kind initiative.

The objective of this thesis is to evaluate the engineering properties of Municipal Solid Waste (MSW) that are necessary in the design of landfills. The engineering properties of MSW such as compressibility, shear strength, stiffness and hydraulic conductivity are crucial in design and construction of landfills. The variation of the engineering properties with time, age and degradation are of paramount importance in the field of landfill engineering. There is a need to address the role of the engineering properties in landfill engineering as it is not apparent how the engineering characteristics vary with time. The thesis presents the results of study of the engineering properties of MSW comprehensively and develops experimental data for design of MSW landfills. The work includes the study of the index properties and the engineering properties of MSW such as compressibility, shear strength, shear modulus and damping ratio and a detailed experimental study of the bioreactor landfill. The components of settlements, variation of shear strength with respect to unit weight and particle size are determined experimentally and analyzed. The dynamic properties such as shear modulus and material damping ratio and its variation with parameters such as unit weight, load, amplitude, degradation and moisture content are studied and analyzed. The normalized shear modulus reduction curve which is used in the seismic analysis of the landfills is developed for MSW based on the experimental results and previous studies. A pilot-scale bioreactor was setup in the laboratory for long term monitoring of the settlement, temperature variation and gas production simultaneously. The parameters of interest viz, pH, BOD, COD, conductivity, alkalinity, methane and carbon-di-oxide were determined. The generated data can be effectively used in the engineered design of landfills. For a better understanding, the present thesis is divided into the following eight chapter Chapter 1 provides a general introduction to the thesis with respect to the importance of engineering properties of MSW and presents the organization of the thesis. Chapter 2 presents a detailed review of literature pertaining to the basic, index and the engineering properties of MSW namely compressibility, shear strength, shear modulus and damping ratio, bioreactor landfill and also the scope of the study. Chapter 3 includes the materials and methods followed in the thesis. Chapter 4 presents the evaluation of compressibility characteristics of MSW including the components of settlement and the settlement model parameters. Chapter 5 presents the determination of the shear strength properties of MSW using direct shear tests and triaxial tests. The variation of the strength with respect to unit weight and the particle size is examined. The results are examined in terms of strength ratio and stiffness ratio and the implications are discussed. Chapter 6 presents the study of the dynamic characters of MSW. The variation of the shear modulus and damping ratio with respect to unit weight, confining pressure, loading frequency, decomposition and moisture content are analyzed. Normalized shear modulus reduction and damping curves are proposed for seismic analysis. Chapter 7 presents the study of the conventional and the bioreactor landfill in a small scale laboratory setup. A large scale experimental setup is fabricated to study the characteristics of a bioreactor landfill and includes the long term monitoring and analysis of temperature, gas, settlement and leachate characteristics periodically. The results of the comprehensive study are presented in this chapter. Chapter 8 summarizes the important conclusions from the various experimental studies reported in this dissertation. Conclusions and the scope of future work are presented. A detailed list of references and the list of publications from the thesis are presented at the end. Appendix A presents the life cycle analysis and life cycle cost analysis of MSW land disposal options. The land disposal options such as open dumps, engineered landfills and bioreactor landfills are analyzed in this study.

Introduction: Sustainability is humanity’s collective ability to sustain development that meets the needs of the present without compromising the ability of the future generations to meet their own needs. Preceding closely to the World Commission on Environment and Development (WCED) Report of 1987, the General Assembly has adopted the UN Declaration, in 1986 [GA RES. 41/128] and has re-emphasized its importance in the UN Millennium Declaration, 2000. Given this anthropocentric rights basis of sustainability it becomes necessary to understand what this ability and development are with respect to the individual human. Problems of relevance, whose resolution benefits more people in general, are often intractable to the methods of rigorous problem-solving (1). Systemic problems of development score high on relevance, low on being amenable to rigor (1) and are considered wicked in nature (2). Consequently, the concern for sustaining human development is wicked and hence calls for taking a design approach as design is considered good at resolving wicked problems(3). This suggests that the collective ability for sustainability with respect to the individual is design ability i.e. to specify solutions that satisfy requirements arising from having to meet self-determined individual (human) developmental needs. However, literature connecting design, sustainability and human development systemically is found lacking and calls for conducting integrative trans-disciplinary research. Prevention and remedial of consequences of technology to the habitability of earth requires the identification, understanding and control of interactions between humans and between humans and the earth systems. These interactions need to be identified generally and understood systemically in the context of being able to sustain human development. However, despite this need for research in interactions and an integrative framework for informing interventions (4) to prevent or remedy unsustainable situations literature that addresses this need is found inadequate. Research Objective: To develop a descriptive model of interaction to be able to identify and describe interactions and understand interactions at human-scale. To develop a prescriptive framework within which to situate the prevention and remedial of problems related to un sustainability by design and prescribe conditions that ensure coherence of design interventions to principles. Research Method: As is the nature of problems of relevance, the proposed research by nature spans multiple disciplines. Descriptive inquiry into widespread literature spanning conservation, development, systems theory and design is conducted before synthesizing a descriptive model of interaction that situates design cycle as a natural cycle based on interpretation of entropy and Gestalt theory of human perception. A manual discourse analysis of a section of the WCED report is undertaken to inquire into the conceptual system (worldview) behind sustainable development to understand human interactions based on worldview. Addressing the need for choosing alternative goals of development for sustainability, Sen’s capability approach to human development is adopted after critically reviewing literature in this area and synthesizing an appropriate integration of design ability, tools, (cognitive) extension and design capability for human development. Models based on theories spanning design expertise, psychology and systems thinking are reviewed and synthesized into a prescriptive framework and two intervention scenarios based on it. The framework, intervention scenarios and the model are illustrated with evidence from qualitative bibliographic analysis of several cases related to sustaining human development in principle. Results: Sustainability is proposed as a human ability; this human ability is proposed to be design ability to sustain human development. A descriptive model of interaction that situates anthropogenic action as a design cycle is proposed. Based on this model, identifying entities and interactions is demonstrated with examples. It is proposed that humans interact, designing, due to and based on their worldview. Expansion of capabilities as stated in capability approach to lead to human development is ‘extension’ of design ability to design capability mediated by tools. Personal and interpersonal interactions at human scale are described through tool-use categories. A prescriptive framework for sustainability by design that holds human needs as central to interventions for sustainability is proposed. Based on this framework, pro-active and reactive scenarios of design intervention for prevention and remedial of un sustainability are constructed and demonstrated using several cases. Summary: Problems of relevance like sustaining human development are wicked in nature and require knowledge and action mutually informing each other. Addressing the inter-disciplinary nature of the problem requires a design approach as design is known to integrate knowledge from several disciplines to resolve wicked problems. The imperative to be able to sustain human development provides the widest profile of requirements to be met and design is shown to be central to meeting these requirements at the various scales that they surface. Sustainability is defined as humanity’s collective ability to develop meeting needs of the present without compromising the ability of the future generations for meeting their own needs. This collective ability translates to the individual’s design ability to specify solutions that satisfy requirements arising out of having to meet self-determined developmental needs. The process of ‘expansion’ -- of capabilities that free people choose and value – that realizes human development is the process of tools affording the extension of design ability to design capability necessary for progressively satisfying requirements arising out of self-determined needs of increasing complexity. It is proposed that humans interact, designing based on and due to their worldview. Personal and interpersonal interactions at human scale are described through tool-use categories. A prescriptive framework for sustainability by design is developed stating conditions to guide systemic design interventions for preventing and remedying unsustainability within pro-active and reactive scenarios respectively. A descriptive model of interaction is developed to situate and enable understanding of interactions. The framework, scenarios and the model are illustrated using several cases related to sustaining human development.