Whole life sustainability assessment at the building industry and constructed assets, through the whole life costing assessment and life cycle costing assessment evaluating the economic and financial aspects

Net-zero energy buildings can be understood as buildings, that for a given time, generate as much energy as they consume. Either, from the point of view of supply or consumption, energy availability is related to some basic issues such as source (s), conversion, distribution, utilization, waste, optimization, efficiency and autonomy. These issues reveal the complexity of the subject of energy and justify the special attention given to it by the academic community. To obtain tangible results in the analysis of these systems, in our study we focus on the modelling and optimization of energy solutions applied to buildings or similar systems. On the other hand, the time frame of the analysed objects was extended to their expected life cycle period. The main objectives were stablished as: - Verify and analyse the state-of-the-art of renewable energy solutions for buildings and constructed assets and the applicability of life cycle costing analysis to these issues; - Configure reproducible models of buildings and their main electrical loads, via Computer Aided Process Engineering tools, to proceed simulations and optimization, considering as primary energy source solar energy; - Quantify, using real-life and hypothetical case studies, the benefits of the proposed solutions, aiming the whole life sustainability assessment through the reduction of the whole life cycle costing; and -Guarantee the reproducibility of the models and main general results of this study and make them public, to contribute with their applicability and further researches. A Literature Review was performed, focusing on Whole Life Costing Assessment (WLCA), that encompasses Life Cycle Costing Assessment (LCCA) and the adoption of this methodology for the economic pillar evaluation of the Sustainability Life Cycle in the Building and Solar Energy sectors. Research showed the effectiveness of this methodology as the main component for assessing sustainability in the economic domain, and the relationship with the primary methods of environmental and social areas. The energy industry has been responsible for a significant number of publications, and the use of LCCA for different scale solar energy solutions as vehicles, houses, buildings, highways, rural properties and power plants indicates the usefulness of this methodology. In the large-scale solar energy solutions, for Solar Photo Voltaic (SPV) and Concentrating Solar Power (CSP), the use of LCCA can upraise the advantages for choosing or integrating both solutions. In minor scale solar energy solutions where the crescent technological evolution of SPV Cells has resulted in higher energy efficiency rates, the use of the LCCA can demonstrate the sensitive reduction on the Levelized Cost of Energy (LCOE), reflecting on the feasibility of solutions as the Net-Zero Energy Buildings (NZEB). Also clarifying the feasibility of their critical ancillary solutions, named Electrical Energy Storages (EES) and the Thermal Energy Storages (TES). These facts allied to the crescent number of studies and publications shows that LCCA is a promising field of studies and a powerful tool to achieve a most complete and reliable Life Cycle Sustainability Assessment of solar energy technologies and the solar energy implementation projects, mainly in the design phase. However, often the selected solar systems for buildings are analysed from an energetic and economic point of view rather than from detailed feasibility analysis and a life cycle perspective. In the first case study, the objective was to evaluate with pre-design modelling and simulation the electrical demand of a Logistics Centre and determine the adequate system configurations, considering the Life Cycle Costing (LCC). The energy supplied by the photovoltaic (PV) panels connected with the grid brings more flexibility for energy management, and the energy surplus is an essential factor to be considered. A base case was established and three alternative scenarios for optimization considered. Combining the use of TRNSYS 18 - Simulation Studio and its optimization library component, GenOpt - Generic Optimization Program, different options of grid energy contracts were simulated. They consider the variable tariffs and the integration with PV. Based on the LCC the GenOpt performed the Single-Objective Optimization (SOO) process, also considering the Payback Period (PBP) of investments. This approach allowed envisaging possible configurations reducing up to a quarter of annual grid energy consumption and around 21% the LCC in a timeframe of 20 years. The PBP of investments is below six years. These results serve as input for the design and operation set up. In the second case study, a hypothetical building was configured with detailed loads for tropical climate and systems to simulate different configurations of an air-cooled chiller associated with PV and TES. The objective was to show that the cooling systems, as one of the most energy consuming systems can have their efficiency increased if it is associated with photovoltaic panels (PV) and thermal energy storage systems (TES). For tropical climate regions, the Brazilian National Energy Planning, PNE 2030 (Ministerio de Minas e Energia 2006) indicates that the refrigeration and space cooling consumes a significant amount of energy, reaching 32% and 34% in residential and commercial buildings, doubling the contribution compared to the United States Also using the TRNSYS 18 - Simulation Studio, a set of scenarios were simulated, and their outputs analysed in a life cycle perspective using Life Cycle Costing (LCC) for the calculations. The simulations considered variations in sizing and operability of the systems and generated results that establish a pathway toward a zero-energy building, using input data and parameter from manufacturers and standardized level of comfort for the building occupants to generate the feasible scenarios. The modelling and simulation of different scenarios allowed envisage the most economic configurations for buildings in a life cycle perspective, though the LCC reduction within a safe range of operability considering the energy efficiency and consequently the sustainability aspects of buildings. The results can be used as premises for initial design or for planning retrofits of the buildings, aiming the zero-energy balance.