scholarly journals Energy Benchmarking of Existing Office Stock in Spain: Trends and Drivers

2019 ◽  
Vol 11 (22) ◽  
pp. 6356 ◽  
Author(s):  
Gangolells ◽  
Casals ◽  
Ferré-Bigorra ◽  
Forcada ◽  
Macarulla ◽  
...  

Buildings play a central role in the clean energy transition, which is why it is vital to understand how energy is consumed in this sector. Energy performance certificate databases are considered a key source of information on the characteristics of built building stock. Despite a growing portfolio of studies based on information from such databases, little is known about energy consumption in offices. This paper explores the modelled energy performance of existing offices in Spain, using data from 13,701 energy performance certificates collected by the Catalan Institute of Energy (ICAEN) in 2013–2018. Offices were found to consume between 202.66 and 212.10 kWhp/m2·year and were mostly ranked in classes C and D (~64%). Offices with E, F or G labels represent ~28% of the sample while A and B energy ratings are very scarce (~8%). Key drivers of energy consumption variation were found to be the office type, construction period, climate zone, renewable energy use, energy certification procedure and motivation for obtaining an energy performance certificate. Ownership was not found to affect average calculated energy consumption. The results will help policy makers to plan future energy conservation strategies.

Mathematics ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 163
Author(s):  
Carlos-Antonio Domínguez-Torres ◽  
Ángel Luis León-Rodríguez ◽  
Rafael Suárez ◽  
Antonio Domínguez-Delgado

In recent years, there has been growing concern regarding energy efficiency in the building sector with energy requirements increasing worldwide and now responsible for about 40% of final energy consumption in Europe. Previous research has shown that ventilated façades help to reduce energy use when cooling buildings in hot and temperate climates. Of the different ventilated façade configurations reported in the literature, the configuration of ventilated façade with window rarely has been studied, and its 3D thermodynamic behavior is deserving of further analysis and modeling. This paper examines the thermal behavior of an opaque ventilated façade with a window, in experimentally and numerical terms and its impact in energy savings to get indoor comfort. Field measurements were conducted during the winter, spring and summer seasons of 2021 using outdoor full scale test cells located in Seville (southern Spain). The modeling of the ventilated façade was carried out using a three-dimensional approach taking into account the 3D behavior of the air flow in the air cavity due to the presence of the window. The validation and comparison process using experimental data showed that the proposed model provided good results from quantitative and qualitative point of view. The reduction of the heat flux was assessed by comparing the energy performance of a ventilated façade with that of an unventilated façade. Both experimental and numerical results showed that the ventilated façade provided a reduction in annual total energy consumption when compared to the unventilated façade, being compensated the winter energy penalization by the summer energy savings. This reduction is about 21% for the whole typical climatic year showing the ability of the opaque ventilated façade studied to reduce energy consumption to insure indoor comfort, making its suitable for use in retrofitting the energy-obsolete building stock built in Spain in the middle decades of the 20 century.


2021 ◽  
Vol 13 (24) ◽  
pp. 13863
Author(s):  
Yana Akhtyrska ◽  
Franz Fuerst

This study examines the impact of energy management and productivity-enhancing measures, implemented as part of LEED Existing Buildings Operations and Management (EBOM) certification, on source energy use intensity and rental premiums of office spaces using data on four major US markets. Energy management practices, comprised of commissioning and advanced metering, may reduce energy usage. Conversely, improving air quality and occupant comfort in an effort to increase worker productivity may in turn lead to higher overall energy consumption. The willingness to pay for these features in rental office buildings is hypothesised to depend not only on the extent to which productivity gains enhance the profits of a commercial tenant but also on the lease arrangements for passing any energy savings to the tenant. We apply a difference-in-differences method at a LEED EBOM certification group level and a multi-level modelling approach with a panel data structure. The results indicate that energy management and indoor environment practices have the expected effect on energy consumption as described above. However, the magnitude of the achieved rental premiums appears to be independent of the lease type.


2017 ◽  
Vol 28 (7) ◽  
pp. 673-686 ◽  
Author(s):  
Pengfei Sheng ◽  
Yaping He ◽  
Xiaohui Guo

There is no consensus about the impact of urbanization on energy efficiency. We seek to fill this gap in literature using data from 78 countries for the period of 1995 through 2012. Extending the Stochastic Impacts by Regression on Population, Affluence, and Technology model, we identify the impact of urbanization on energy consumption and efficiency. Results of generalized method of moments estimation indicate that the process of urbanization leads to substantial increases in both the actual and the optimal energy consumption, but a decrease in efficiency of energy use. In addition, we find that the extent to which energy inefficiency correlates with urbanization is greater in countries with higher gross domestic product per capita.


2014 ◽  
Vol 39 (2) ◽  
pp. 78-83
Author(s):  
Henk Visscher ◽  
Dasa Majcen ◽  
Laure Itard

The energy saving potential of the building stock is large and considered to be the most cost efficient to contribute to the CO2 reduction ambitions. Severe governmental policies steering on reducing the energy use seem essential to stimulate and enforce the improvement of the energy performance of buildings with a focus on reducing the heating and cooling energy demand. In Europe the Energy Performance of Buildings Directive is a driving force for member states to develop and strengthen energy performance regulations for new buildings and energy certificates for the building stock. The goals are to build net zero energy new buildings in 2020 and to reach a neutral energy situation in the whole stock by 2050. More and more research projects deliver insight that the expected impact of stricter regulations for newly built houses is limited and the actual effects of energy savings through housing renovations stay behind the expectations. Theoretical energy use calculated on base of the design standard for new houses and assessment standards for Energy Performance Certificates of existing dwellings differ largely from the measured actual energy use. The paper uses the findings of some Post Occupancy Evaluation research projects. Is the energy saving potential of the housing stock smaller than expected and should we therefore change the policies?


2018 ◽  
Vol 9 (2) ◽  
pp. 115-121 ◽  
Author(s):  
B. Kiss ◽  
ZS. Szalay

Building life cycle assessment is getting more and more attention within the topic of environmental impact caused by the built environment. Although more and more research focus on the embodied impact of buildings, the investigation of the operational energy use still needs attention. The majority of the building stock still does not comply with the nearly zero energy requirements. Also, in case of retrofitting, when most of the embodied impact is already spent on the existing structures (and so immutable), the importance of the operational energy rises. There are several methods to calculate the energy performance of buildings covering the range from simplified seasonal methods to detailed hourly energy simulations. Not only the accuracy of the calculations, but the computational time can be significantly different within the methods. The latter is especially important in case of optimization, when there is limited time to perform one calculation. Our research shows that the use of different calculation techniques can lead to different optima for environmental impacts in case of retrofitting. In this paper we compare these calculation methods with focus on computational time, accuracy and applicability to environmental optimization of buildings. We present the results in a case study of the retrofitting of a middle-sized apartment house in Hungary.


2020 ◽  
Vol 12 (1) ◽  
pp. 351 ◽  
Author(s):  
Hossein Omrany ◽  
Veronica Soebarto ◽  
Ehsan Sharifi ◽  
Ali Soltani

Residential buildings are responsible for a considerable portion of energy consumption and greenhouse gas emissions worldwide. Correspondingly, many attempts have been made across the world to minimize energy consumption in this sector via regulations and building codes. The focus of these regulations has mainly been on reducing operational energy use, whereas the impacts of buildings’ embodied energy are frequently excluded. In recent years, there has been a growing interest in analyzing the energy performance of buildings via a life cycle energy assessment (LCEA) approach. The increasing amount of research has however caused the issue of a variation in results presented by LCEA studies, in which apparently similar case studies exhibited different results. This paper aims to identify the main sources of variation in LCEA studies by critically analyzing 26 studies representing 86 cases in 12 countries. The findings indicate that the current trend of LCEA application in residential buildings suffers from significant inaccuracy accruing from incomplete definitions of the system boundary, in tandem with the lack of consensus on measurements of operational and embodied energies. The findings call for a comprehensive framework through which system boundary definition for calculations of embodied and operational energies can be standardized.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4954
Author(s):  
Mohammad AlHashmi ◽  
Gyan Chhipi-Shrestha ◽  
Kh Md. Nahiduzzaman ◽  
Kasun Hewage ◽  
Rehan Sadiq

Rapid population growth has led to significant demand for residential buildings around the world. Consequently, there is a growing energy demand associated with increased greenhouse gas (GHG) emissions. The residential building energy demand in arid countries such as Saudi Arabia is supplied with fossil fuel. The existing consumption pattern of fossil fuels in Saudi Arabia is less sustainable due to the depletion of fossil fuel resources and resulting environmental impacts. Buildings built in hot and arid climatic conditions demand high energy for creating habitable indoor environments. Enormous energy is required to maintain a cool temperature in hot regions. Moreover, climate change may have different impacts on hot climatic regions and affect building energy use differently. This means that different building interventions may be required to improve the performance of building energy performance in these geographical regions, thereby reducing the emissions of GHGs. In this study, this framework has been applied to Saudi Arabia, a hot and arid country. This research proposes a community–government partnership framework for developing low-carbon energy in residential buildings. This study focuses on both the operational energy demand and a cost-benefit analysis of energy use in the selected geographical regions for the next 30 years (i.e., 2050). The proposed framework primarily consists of four stages: (1) data collection on energy use (2020 to 2050); (2) setting a GHG emissions reduction target; (3) a building intervention approach by the community by considering cost, energy, and GHG emissions using the Technique for Order of Performance by Similarity to the Ideal Solution (TOPSIS) to select the best combinations in each geographical region conducting 180 simulations; and (4) a clean energy approach by the government using grey relational analysis (GRA) to select the best clean energy system on the grid. The clean energy approach selected six different renewable power generation systems (i.e., PV array, wind turbine, hybrid system) with two storage systems (i.e., battery bank and a combination of electrolyte, fuel cell, and hydrogen tank storage). This approach is designed to identify the best clean energy systems in five geographical regions with thirty scenario analyses to define renewable energy-economy benefits. This framework informs through many engineering tools such as residential building energy analysis, renewable energy analysis, multi-criteria decision analysis (MCDA) techniques, and cost-benefit analysis. Integration between these engineering tools with the set of energy policies and public initiatives is designed to achieve further directives in the effort to reach greater efficiency while downsizing residential energy demands. The results of this paper propose that a certain level of cooperation is required between the community and the government in terms of financial investments and the best combinations of retrofits and clean energy measures. Thus, retrofits and clean energy measures can help save carbon emissions (enhancing the energy performance of buildings) and decrease associated GHG emissions, which can help policy makers to achieve low-carbon emission communities.


2020 ◽  
Vol 20 (1) ◽  
pp. 24-34
Author(s):  
Farheen Bano ◽  
Vandana Sehgal

In this study, the energy consumption of three government and three private office buildings in Lucknow was investigated, and the energy performance index (EPI) for each building was determined. The main purpose of this research was to assess the energy usage of the buildings and identify factors affecting the energy usage. An analysis was performed using data from an energy audit of government buildings, electricity bills of private office buildings, and an on-site visit to determine building envelope materials and its systems. The annual energy consumption of buildings has been evaluated through EPI. The EPI, measured in kilowatt hour per square meter per year, is annual energy consumption in kilowatt hours divided by the gross floor area of the building in square meters. In this study, the energy benchmark for day-time-use office buildings in composite climate specified by Energy Conservation Building Code (ECBC) has been compared with the energy consumption of the selected buildings. Consequently, it has been found that the average EPI of the selected buildings was close to the national energy benchmark indicated by ECBC. Moreover, factors causing inefficient energy consumption were determined, and solutions for consistent energy savings are suggested for buildings in composite climate.


2021 ◽  
Author(s):  
M.R. Amjath ◽  
◽  
H. Chandanie ◽  
S.D.I.A. Amarasinghe ◽  
◽  
...  

It has been observed that inefficient buildings consume three to five times more energy than efficient buildings. Subsequently, improving the Energy Efficiency (EE) of existing buildings, which account for a significant portion of the energy consumption of the building sector, has become a top priority. Also, Heating, Ventilation, and Air Conditioning (HVAC) and lighting systems typically account for three-quarters of a building's energy consumption. Hence, focus on the energy efficiency improvements associated with these subsystems is entailed to optimise the energy use of buildings in comparison to other energy consumers. Energy Retrofit (ER) is defined as the main approach in improving the energy efficiency of buildings to achieve energy reduction goals. Nevertheless, there is a general lack of awareness regarding ER. Thus, the purpose of this article is to bridge this research gap by critically reviewing the applicable literature on ER. The paper first analysed the role of retrofits in buildings concerning optimising energy performance. The paper also discusses the implementation process of ER, which includes five steps viz. pre-retrofit survey, energy auditing, and performance assessment, identification of suitable and feasible retrofit options, site implementation and commissioning, and validation and verification. Further, different types of ER applicable to HVAC and lighting systems are discussed. In their endeavor to enhance the EE of existing buildings, practitioners could apply the findings of this study, as a basis to understand the available ER types and as a measure to gauge the efficiency of existing buildings, which will facilitate effective decision-making.


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