scholarly journals The nZEB Requirements for Residential Buildings: An Analysis of Thermal Comfort and Actual Energy Needs in Portuguese Climate

2021 ◽  
Vol 13 (15) ◽  
pp. 8277
Author(s):  
Jaime Resende ◽  
Helena Corvacho

As of now, in the EU, all new buildings will have to comply with the requirements for nearly zero energy buildings (nZEB). Portugal defines limits for the maximum useful energy needs for heating and for the maximum primary energy needs and establishes that 50% of primary energy needs must be covered by local renewable energy sources, based on the dwellings’ nominal condition of use. However, the actual use is different. Thus, a simulation tool is used to assess thermal comfort and energy needs for different conditions of use of a dwelling complying with nZEB requirements. Eight different locations are chosen, covering all Portuguese climate zones. The nZEB requirements lead to unusually high levels of thermal insulation, especially in the coldest regions, so special care must be taken by the designers to avoid overheating in summer. Without using HVAC system, some discomfort is found but comfort is possible with low energy consumption. Furthermore, the compliance with nZEB requirements proved to be enough to ensure that a significant percentage of useful energy needs for heating, cooling and domestic hot water is supplied by local renewable energy sources. This is key in order to overcome the high rate of energy poverty in Portugal.

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5984
Author(s):  
Hanna Jędrzejuk ◽  
Dorota Chwieduk

This paper analyses possibilities of refurbishment of Warsaw’s residential buildings towards standards of the Positive Energy District. The annual final energy consumption in the city in 2019 for the district heating was 8668 GWh, gas (pipelines) was 5300 GWh, electricity from the grid was 7500 GWh, while the emission of the carbon dioxide was 5.62 × 109 kg. The city consists of 18 districts, which are heterogeneous in terms of typology and structure of buildings. The great variety of buildings can be seen, for example, by the annual final energy demand for space heating and hot water preparation per unit of room area. This annual index ranges from over 400 kWh/m2 in historic buildings to 60 kWh/m2 in modern buildings. A reduction in the consumption of non-renewable energy sources and carbon dioxide emissions can be achieved by improving the energy standard of residential buildings and by using renewable energy sources: solar energy, geothermal energy and biogas. The potential barriers for achieving the status of a positive energy district, for example, problems connected with ownership, financing new investments and refurbishment and legal boundaries, have been identified. Moreover, changing the existing electrical grid and district heating systems in urban areas in Warsaw requires comprehensive modernization of practically the entire city’s infrastructure.


Smart Cities ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 471-495
Author(s):  
Viktor Stepaniuk ◽  
Jayakrishnan Pillai ◽  
Birgitte Bak-Jensen ◽  
Sanjeevikumar Padmanaban

The smart active residential buildings play a vital role to realize intelligent energy systems by harnessing energy flexibility from loads and storage units. This is imperative to integrate higher proportions of variable renewable energy generation and implement economically attractive demand-side participation schemes. The purpose of this paper is to develop an energy management scheme for smart sustainable buildings and analyze its efficacy when subjected to variable generation, energy storage management, and flexible demand control. This work estimate the flexibility range that can be reached utilizing deferrable/controllable energy system units such as heat pump (HP) in combination with on-site renewable energy sources (RESs), namely photovoltaic (PV) panels and wind turbine (WT), and in-house thermal and electric energy storages, namely hot water storage tank (HWST) and electric battery as back up units. A detailed HP model in combination with the storage tank is developed that accounts for thermal comforts and requirements, and defrost mode. Data analytics is applied to generate demand and generation profiles, and a hybrid energy management and a HP control algorithm is developed in this work. This is to integrate all active components of a building within a single complex-set of energy management solution to be able to apply demand response (DR) signals, as well as to execute all necessary computation and evaluation. Different capacity scenarios of the HWST and battery are used to prioritize the maximum use of renewable energy and consumer comfort preferences. A flexibility range of 22.3% is achieved for the scenario with the largest HWST considered without a battery, while 10.1% in the worst-case scenario with the smallest HWST considered and the largest battery. The results show that the active management and scheduling scheme developed to combine and prioritize thermal, electrical and storage units in buildings is essential to be studied to demonstrate the adequacy of sustainable energy buildings.


2021 ◽  
Vol 19 ◽  
pp. 205-210
Author(s):  
Milan Belik ◽  

This project focuses on optimisation of energy accumulation for various types of distributed renewable energy sources. The main goal is to prepare charging – discharging strategy depending on actual power consumption and prediction of consumption and production of utilised renewable energy sources for future period. The simulation is based on real long term data measured on photovoltaic system, wind power station and meteo station between 2004 – 2021. The data from meteo station serve as the input for the simulation and prediction of the future production while the data from PV system and wind turbine are used either as actual production or as a verification of the predicted values. Various parameters are used for trimming of the optimisation process. Influence of the charging strategy, discharging strategy, values and shape of the demand from the grid and prices is described on typical examples of the simulations. The main goal is to prepare and verify the system in real conditions with real load chart and real consumption defined by the model building with integrated renewable energy sources. The system can be later used in general installations on commercial or residential buildings.


2021 ◽  
Vol 144 ◽  
pp. 14-21
Author(s):  
Vladimir P. Polevanov ◽  

The growth in primary energy consumption in 2019 by 1.3% was provided by renewable energy sources and natural gas, which together provided 75% of the increase. China in the period 2010–2020 held a leading position in the growth of demand for energy resources, but according to forecasts, India will join it in the current decade.


Author(s):  
Hasan Dinçer ◽  
Serhat Yüksel ◽  
Hüsne Karakuş

Renewable energy sources are clean energy sources that meet the energy needs in a sustainable way. Therefore, it is necessary to invest in renewable energy sources. However, there are some difficulties in renewable energy investments. It has problems such as high initial installation cost, underdeveloped technological infrastructure, and insufficient financial support. Several financial products are being developed in order to overcome the mentioned difficulties. In this context, the purpose of this study is to explain the role of green sukuk in the financing of renewable energy investments. Depending on this purpose, the study has been examined with a literature review. The production of renewable energy sources can be encouraged with green sukuk. However, green sukuk is an advantage for Islamic companies that want to realize environmental projects. On the other hand, it offers the opportunity to the environmentally friendly Islamic investors to evaluate their savings.


2019 ◽  
Vol 887 ◽  
pp. 148-155
Author(s):  
Paola Penna ◽  
Oscar Stuffer ◽  
Alexandra Troi ◽  
Valentina Carí

What Americas Cup and a heritage building have in common? They both aim at innovative technologies and cutting-edge solutions. The owner of the project, an ex-crew member of the most famous sailing match race in the world, pushed the planning team to develop extraordinary solutions for his house. The house, Villa Castelli, is an historical listed building located on the Como lake. During its history, it has been transformed many times, giving as results a non-uniform structure composed by different construction technologies. The aims of the owner were: an overall refurbishment particularly focused on energy efficiency, the exploitation of renewable energy sources based on-site production and a fixed budget. To reach these goals, the energy needs have been reduced improving the performance of the thermal envelope. Then, the building's technical systems have been re-developed in order to exploit as much as possible available renewable energy sources. From the very beginning, it was clear that, for finding optimal solutions, a multidisciplinary approach was necessary. The design approach should be the result of a shared approach integrating different fields, such as creative design, technology, knowledge of material properties, building physics. The great synergy among building envelope retrofitting, innovative technological solutions and the deployment of renewable energy sources allows the transformation of this historical listed building into an outstanding example of a nearly zero energy building (nZEB).


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ardasher Namazbay Yussupov ◽  
Akmaral Ardasherovna Yussupova

PurposeThe purpose of this article discusses the design of underground eco-houses using a dome structure of light construction while taking into account the historical experience of the development of the local population. This article considered the traditions of folk architecture and modern sophistication in the creation of energy-efficient eco-houses in foreign countries in the context of architecture and construction of affordable residential homes for the local population.Design/methodology/approachThe research presented in this paper was motivated by the need for developing agro-tourism facilities in hard-to-reach areas of the Silk Road in Southern Kazakhstan causes the construction of eco-houses built using local construction materials. Since ancient times in Southern Kazakhstan and during seasonal migrations in yurts of light construction, people have lived in mud-brick houses deep in the ground. Along with architectural and artistic solutions in building construction, great importance was attached to saving material resources, labour costs and achieving heat stability of residential buildings.FindingsIn the architectural and planning solution of the eco¬-house, progressive directions of construction of agrotechnical structures using renewable energy sources are adopted. Particular importance was given to the choice of the construction site on an elevated area nearby historical monuments and a favourable season for the construction of eco-houses with considering the natural and climatic characteristics of rural areas of Southern Kazakhstan.Research limitations/implicationsThis paper discussed the issues of insulation, ventilation and improving the eco-house microclimate comfort using local building materials. Improving the architectural and artistic expressiveness of the eco-house in terms of the tradition of folk architecture was also explicitly discussed in this paper.Practical implicationsTables with the justification of expediency of construction of economical eco-houses in natural and climatic conditions of Kazakhstan and Central Asia are provided. The results help to improve the energy efficiency of eco-houses in Kazakhstan by using renewable energy sources.Social implicationsSocial benefits are associated with the use of local raw materials. Eco-houses built from traditional building materials can become accessible to a wide range of people and stimulate the development of small businesses. This may be associated with the construction of eco-houses to serve visiting tourists in remote picturesque oases, as well as the manufacture of dome structures, felt products and the preparation of reed panels and so on.Originality/valueThe thermotechnical characteristics of the region's ground energy are given, which can significantly save the cost of heating the eco-house. Solutions for optimal insolation, ventilation of the eco-house are provided, taking into account the natural and climatic conditions of Southern Kazakhstan.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Baraka Kichonge ◽  
Iddi S. N. Mkilaha ◽  
Geoffrey R. John ◽  
Sameer Hameer

The study analyzes the economics of renewable energy sources into electricity generation in Tanzania. Business as usual (BAU) scenario and renewable energy (RE) scenario which enforce a mandatory penetration of renewable energy sources shares into electricity generations were analyzed. The results show total investment cost for the BAU scenario is much lower as compared to RE scenario while operating and maintenance variable costs are higher in BAU scenario. Primary energy supply in BAU scenario is higher tied with less investment costs as compared to RE scenario. Furthermore, the share of renewable energy sources in BAU scenario is insignificant as compared to RE scenario due to mandatory penetration policy imposed. Analysis concludes that there are much higher investments costs in RE scenario accompanied with less operating and variable costs and lower primary energy supply. Sensitivity analysis carried out suggests that regardless of changes in investments cost of coal and CCGT power plants, the penetration of renewable energy technologies was still insignificant. Notwithstanding the weaknesses of renewable energy technologies in terms of the associated higher investments costs, an interesting result is that it is possible to meet future electricity demand based on domestic resources including renewables.


Sign in / Sign up

Export Citation Format

Share Document