scholarly journals Prospects of Transforming Conventional Commercial Buildings to Net Zero Energy Building – Balancing the Economic Aspects with Energy Patterns

2021 ◽  
Vol 25 (1) ◽  
pp. 990-1002
Author(s):  
Danyal Shuja ◽  
Syed Shujaa Safdar Gardezi ◽  
Muhammad Rashid Idrees

Abstract Energy crises has been a serious concern for economies especially for developing ones. The building stocks developed through conventional methods pose serious barriers towards sustainable energy consumption patterns. The transformation of such existing facilities into Net Zero Energy Buildings (NZEB) can offer a valuable opportunity to manage the challenging energy loads. However, cost aspect of such transformations remains the key and explored in current study to assess a breakeven point with the energy conservations. Four commercial buildings, three and four story, were selected as case studies. 3D digital models were developed for energy analysis through cloud computing. Comparative analysis for energy consumption patterns was performed in four phases. For conventional approach, the annual consumptions ranged from 310 kWh/m2/yr to 563 kWh/m2/yr. Based upon the local conditions, roof insulation and PV were adopted as NZEB parameters. This resulted a maximum energy saving of 6 %. The corresponding cost analysis observed an addition expense of almost 11 % for such incorporation with an average payback period of 4.5 years.

2021 ◽  
Author(s):  
◽  
Shaan Cory

This thesis explores the feasibility of converting the current New Zealand commercial building stock to Net Zero Energy (NZE). The analysis presented is grounded in real building performance and construction information. The goal was to establish results that are as realistic as possible to actual building performance. The Net Zero Energy Building (Net ZEB) concept is one of many low energy building movements that respond to the issues of climate change and energy security. The Net ZEB concept strives to reduce demand for energy and then to offset any residual energy consumption with non-CO2 emitting renewable energy technologies. The (re-)design focus for Net ZEBs is to reduce annual energy consumption to be equal to or less than any generated renewable energy. This is an important concept since approximately 40 percent of all energy and emissions worldwide are building related. If all buildings were designed and operated to be NZE, the existing energy can be used by other sectors which will increase energy security. Conversely, reducing the fossil fuel CO2 producing component of the energy consumed by buildings has the benefit of negating building’s contribution to climate change. The Net ZEB concept assumes each building is grid-connected, and balances the energy taken from the grid against the energy put back into the grid over a year. This study exploits the available synergies of the grid connection to achieve NZE for the whole building stock. Thus each individual building does not need to be NZE at the site, but they act as a community to reach NZE collectively. Furthermore, any grid-tied renewable energy does not need to be offset, only the non-renewable portion. A NZE target was calculated to determine the percentage reduction in current energy consumption needed before the current commercial building stock could be considered NZE. It was found that a 45 percent reduction in primary energy would offset all non-renewable CO2 emitting energy supply currently consumed by the New Zealand commercial building stock. Previous studies assessing whether converting an entire stock of commercial buildings to NZE is possible used prototypical building energy models. Prototypical models represent a hypothetical average building and have many assumptions about the way a building is operated. This thesis develops a method that takes a representative sample of real commercial buildings and makes calibrated energy models that can be aggregated to represent energy consumption for all commercial buildings in New Zealand. The developed calibration method makes use of as-built building information and a standardised procedure for identifying the inaccurate model inputs which need to be corrected for a building energy model to be calibrated. To further base the process in reality, a set of Energy Conservation Measures (ECM) that had been implemented in real Net ZEBs worldwide was adopted for the proposed retrofits. These ECMs were combined into Net ZEB solution sets for retrofitting the aggregated commercial building models. Optimisation of the Net ZEB solution sets was performed on hundreds of models to maximise energy savings. It took over six months for all of the optimisations to be completed. This thesis demonstrates the estimated New Zealand commercial building stock’s energy consumption based upon the calibrated energy models was robust by comparing it to an external estimate. It shows that NZE can be achieved by applying well understood Net ZEB solution sets to the New Zealand commercial building stock. 96 percent of the NZE goal is attainable just through demand reduction without the use of onsite renewable energy generation. The additional four percent of reduction required to meet NZE is easily attainable with onsite renewable generation. Another benefit is that the retrofitted commercial buildings will provide improved thermal comfort for the occupants. Having established NZE was possible, this thesis concludes with an analysis of the broader implications of achieving the NZE goal. It identifies the next step would be to design a NZE commercial building stock that reduces the stresses on the existing energy infrastructure. The Solution Set adopted was not developed with the interaction of the building and electrical grid in mind. To have a practical implementation of NZE will require costing and community prioritisation. This would be the next phase of work assessing nationwide NZE retrofit.


2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Mohsen Mahdavi Adeli ◽  
Said Farahat ◽  
Faramarz Sarhaddi

Residential and commercial buildings consume approximately 60% of the world’s electricity. It is almost impossible to provide a general definition of thermal comfort, because the feeling of thermal comfort is affected by varying preferences and specific traits of the population living in different climate zones. Considering that no studies have been conducted on thermal satisfaction of net-zero energy buildings prior to this date, one of the objectives of the present study is to draw a comparison between the thermal parameters for evaluation of thermal comfort of a net-zero energy building occupants. In so doing, the given building for this study is first optimized for the target parameters of thermal comfort and energy consumption, and, hence, a net-zero energy building is formed. Subsequent to obtaining the acceptable thermal comfort range, the computational analyses required to determine the temperature for thermal comfort are carried out using the Computational Fluid Dynamics (CFD) model. The findings of this study demonstrate that to reach net-zero energy buildings, solar energy alone is not able to supply the energy consumption of buildings and other types of energy should also be used. Furthermore, it is observed that optimum thermal comfort is achieved in moderate seasons.


Author(s):  
Mostafa Esmaeili Shayan

The Net Zero Energy Building is generally described as an extremely energy-efficient building in which the residual electricity demand is provided by renewable energy. Solar power is also regarded to be the most readily available and usable form of renewable electricity produced at the building site. In contrast, energy conservation is viewed as an influential national for achieving a building’s net zero energy status. This chapter aims to show the value of the synergy between energy conservation and solar energy transfer to NZEBs at the global and regional levels. To achieve these goals, both energy demand building and the potential supply of solar energy in buildings have been forecasted in various regions, climatic conditions, and types of buildings. Building energy consumption was evaluated based on a bottom-up energy model developed by 3CSEP and data inputs from the Bottom-Up Energy Analysis System (BUENAS) model under two scenarios of differing degrees of energy efficiency intention. The study results indicate that the acquisition of sustainable energy consumption is critical for solar-powered net zero energy buildings in various building styles and environments. The chapter calls for the value of government measures that incorporate energy conservation and renewable energy.


2021 ◽  
Author(s):  
Mohammad Reza Bahrami

Zero Energy Building or Nearly Zero Energy Building or Net Zero Energy Building-roughly means the same thing. ZEB for short is a building that has approximately zero energy consumption. The Zero Energy Consumption does not literally mean that the building does not consume any energy at all, on the contrary it is based on conservation of energy law in Physics. In a nutshell the building also generates energy from renewable resources, which is not just used to meet energy requirements of the building, but the surplus energy is also transferred to a transmission station or other building. Thus, ZEB is achieved. Use of ZEB is very crucial to save non-renewable resources like coal which are used to generate electricity


2021 ◽  
Author(s):  
◽  
Shaan Cory

This thesis explores the feasibility of converting the current New Zealand commercial building stock to Net Zero Energy (NZE). The analysis presented is grounded in real building performance and construction information. The goal was to establish results that are as realistic as possible to actual building performance. The Net Zero Energy Building (Net ZEB) concept is one of many low energy building movements that respond to the issues of climate change and energy security. The Net ZEB concept strives to reduce demand for energy and then to offset any residual energy consumption with non-CO2 emitting renewable energy technologies. The (re-)design focus for Net ZEBs is to reduce annual energy consumption to be equal to or less than any generated renewable energy. This is an important concept since approximately 40 percent of all energy and emissions worldwide are building related. If all buildings were designed and operated to be NZE, the existing energy can be used by other sectors which will increase energy security. Conversely, reducing the fossil fuel CO2 producing component of the energy consumed by buildings has the benefit of negating building’s contribution to climate change. The Net ZEB concept assumes each building is grid-connected, and balances the energy taken from the grid against the energy put back into the grid over a year. This study exploits the available synergies of the grid connection to achieve NZE for the whole building stock. Thus each individual building does not need to be NZE at the site, but they act as a community to reach NZE collectively. Furthermore, any grid-tied renewable energy does not need to be offset, only the non-renewable portion. A NZE target was calculated to determine the percentage reduction in current energy consumption needed before the current commercial building stock could be considered NZE. It was found that a 45 percent reduction in primary energy would offset all non-renewable CO2 emitting energy supply currently consumed by the New Zealand commercial building stock. Previous studies assessing whether converting an entire stock of commercial buildings to NZE is possible used prototypical building energy models. Prototypical models represent a hypothetical average building and have many assumptions about the way a building is operated. This thesis develops a method that takes a representative sample of real commercial buildings and makes calibrated energy models that can be aggregated to represent energy consumption for all commercial buildings in New Zealand. The developed calibration method makes use of as-built building information and a standardised procedure for identifying the inaccurate model inputs which need to be corrected for a building energy model to be calibrated. To further base the process in reality, a set of Energy Conservation Measures (ECM) that had been implemented in real Net ZEBs worldwide was adopted for the proposed retrofits. These ECMs were combined into Net ZEB solution sets for retrofitting the aggregated commercial building models. Optimisation of the Net ZEB solution sets was performed on hundreds of models to maximise energy savings. It took over six months for all of the optimisations to be completed. This thesis demonstrates the estimated New Zealand commercial building stock’s energy consumption based upon the calibrated energy models was robust by comparing it to an external estimate. It shows that NZE can be achieved by applying well understood Net ZEB solution sets to the New Zealand commercial building stock. 96 percent of the NZE goal is attainable just through demand reduction without the use of onsite renewable energy generation. The additional four percent of reduction required to meet NZE is easily attainable with onsite renewable generation. Another benefit is that the retrofitted commercial buildings will provide improved thermal comfort for the occupants. Having established NZE was possible, this thesis concludes with an analysis of the broader implications of achieving the NZE goal. It identifies the next step would be to design a NZE commercial building stock that reduces the stresses on the existing energy infrastructure. The Solution Set adopted was not developed with the interaction of the building and electrical grid in mind. To have a practical implementation of NZE will require costing and community prioritisation. This would be the next phase of work assessing nationwide NZE retrofit.


2014 ◽  
Vol 5 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Cs. Szász

The paper presents an intelligent building (IB) development strategy emphasizing the locally available non-polluting renewable energy resources utilization. Considering the immense complexity of the topic, the implementation strategy of the main energy-flow processes is unfolded, using the net zero-energy building concept (NZEB). Noticeably, in the first research steps the mathematical background of the considered NZEB strategy has been developed and presented. Then careful LabView software-based simulations prove that the adopted strategy is feasible for implementation. The result of the above mentioned research efforts is a set of powerful and versatile software toolkits well suitable to model and simulate complex heating, ventilation and air-conditioning processes and to perform energy balance performance evaluations. Besides the elaborated mathematical models, concrete software implementation examples and measurement data also is provided in the paper. Finally, the proposed original models offer a feasible solution for future developments and research in NZEB applications modelling and simulation purposes.


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