Climate change and energy supply limitation are growing concerns. Solving them requires strong implication from our societies and more and more stakeholders and scientists are therefore interested in energy scenarios publication. They indeed provide options to be investigated in order to set the future strategies to tackle these issues. It is within this context that The Shift Project has launched the Scenario project which main purposes are to clarify this specific prospective field and develop a pedagogical energy scenario modeling tool. The Master Thesis work presented in this report is the result of a six months internship in the company within the Scenario project team, and more particularly within the energy scenario modeling tool development team. Beside the energy demand and supply side of a scenario design stands the energy sector. The work focused on this aspect, which corresponds to all the industry and the energy flows standing in between primary energy resources and our final energy consumption. It can therefore be considered as the global conversion process of the energy, which encompasses conversion efficiencies, energy allocation and the different losses. This energy sector is of main concern when one is dealing with energy scenarios since it can contain many possibilities to be investigated in order to set up different variants. Getting a strong knowledge about the energy sector is then crucial. Nevertheless, the global conversion process between primary and final energy still remains a big black box for many of us and therefore prevents us to realize its role and the means that can be applied to explore even further the possible energy scenarios possibilities.    To counteract this observation, this thesis work was dedicated to analyze the energy sector at world scale by revealing its components and the main levers that could be used to shape the future energy system. This analysis was conducted via the system approach and lead to the development of a methodology to model the energy sector and develop a module in which cursors enable an end-user to generate a wide range of scenarios and explore different resources allocation options etc. This module is part of TSP’s energy scenario modeling tool together with a demand and a supply side modules. This work is intended to provide a clear vision of the energy sector and the key parameters that might be of main importance to initiate variants study for energy scenarios prospects, such as power efficiencies, energy mix or distribution losses.

The residential sector was responsible for 25% of the Final Energy Demand (FED) in the European Union in 2015. Countries in Central and Eastern Europe such as the Czech Republic are particularly concerned with ensuring security of supply at the lowest possible cost in recent years. FED for space heating still corresponds to the largest fraction of the total FED in the residential sector in the Czech Republic. The vast majority of buildings constructed in 1990- 2000 do not comply with current standards for thermal protection and owners often rely on their own financial means when attempting to improve the overall Energy Performance (EP) of buildings. The goal(s) associated with renovation- or refurbishment measures must be defined to clarify the extent of work and consequently minimize investments. The aim of this thesis, a case study, was to use a whole building energy simulation program (IDA-ICE) to get insight into the potential of different retrofitting measures (represented by scenarios) to improve EP of a single-family summer house located in the South Bohemian Region of the Czech Republic. One of the simulated scenarios was the owner ́s suggestion to replace windows and entrance doors. The goal was to reduce FED for space heating to ≤50 kWh.m-2 floor area and year and by doing so attaining the status of a low-energy building. Simultaneously, reduced FED for space heating was supposed to be achieved without compromising air quality and should involve only the most efficient refurbishment measures to minimize the overall work. The scope was strictly limited to EP improving measures without consideration of mechanical ventilation or modification of the currently used space heating system. It was concluded that the owner's suggestion to merely replace windows and entrance doors would be an insufficient solution. SC-4 (i.e. the combined effect of windows and entrance doors replacement and the ground-floor insulation) and SC-5 (i.e. the combined effect of ground-floor insulation and the insulation of external walls and the roof) were deemed to represent the most optimal solutions from the simulated EP improving measures. The goal was achieved in both, i.e. 46.8 kWh.m-2 floor area and year in SC-4 and 44.3 kWh.m- 2 floor area and year in SC-5. Averages of zone air temperatures in selected zones were found to be more stable in SC-4, however, SC-5 performed better when comparing averages of CO2 concentration-values in selected zones on the first floor. Nevertheless, averages of relative humidity and CO2 concentration-values in all simulated scenarios were within the acceptable range of 35-60% and about 520 to 1000 ppm respectively (except for Bedroom 2 zone).

The aim of the research is to explore the differences in final energy consumption and environmental impact of the construction materials related to the atrium alternative and a business-as-usual and evaluate how to improve thermal properties of old buildings that require renovations to fit thermal efficiency standards and comfort in operational conditions while reducing the overall impact of the projects. Results show that for the low-rise atrium most of the parameters related to the final energy demands and environmental impacts of the atrium construction materials are proportional and linear to the increase of the glazing area size. When compared to simply renovating old structures, the atrium alternative can promote a decrease in thermal losses by transmission and increase in incident solar radiation through the glazed area depending on the atrium dimensions and glazing area size. And although cooling, heating, electrical and ventilation demands are raised for the overall demand of the building the construction of an atrium bears less environmental impact than renovating old structures damaged by weather. / <p>2021-04-08</p>