Demonstration of the Nearly Zero Energy Building Concept

Nearly zero energy buildings (nZEB) will become an obligatory energy efficiency standard in Europe. Following to common guidelines in European legislation, the countries investigated technical and economic framework for the preparation of detailed national technical definition of nZEB. Slovenia accepted the nZEB criteria in early 2015. This paper describes the technical and economic background for identification of economically viable concepts of highly energy efficient apartment building. The highrise demonstration building Eco Silver House revealed that meeting nZEB standards was not an easy task, not so much for technical reasons, but mostly due to the processes, inadequate skills, not fully compliant regulation and insufficient possibilities for interaction between the building and energy networks. Analysis of cost effectiveness showed that the Eco Silver House fulfilled minimal requirements of cost-optimal for apartment building with Net Present Value of 272 EUR/m2 and Primary energy use of 79 kWh/ m2?a in line with the Slovenian national cost optimal study of minimum energy performance requirements from the year 2014. At the time, the requirement of 50% share of renewables in final energy use is not fulfilled, but will be easily reached when EU2020 energy efficiency targets set in the Slovenian Energy Act regarding the RES share in district heating systems and public power grid will be gradually implemented. The demonstration project FP7 EE-HIGHRISE confirms that in spite of the barriers, the nZEB minimum requirements defined on profound theoretical studies can be met in practice.

Review on the recent progress of nearly zero energy building frontiers in China

Energy efficiency improvement in Chinese construction has progressed rapidly over the past two decades.Nearly zero energy buildings(NZEBs),as an integrated solution for energy-efficient construction,have gained significant attention during China's 13th Five-Year Plan period,with continuous maturation of the technical system.In this study,a research framework built upon the accomplishments of China's National Key Research and Development Program is developed,and an in-depth analysis of the most cutting-edge research is provided by thoroughly reviewing the work conducted earlier.Developing NZEB in China has been categorized into three stages based on the characteristics of technological development:(1)definition and standards,(2)demonstration and promotion,and(3)cross-domain integration.This study discerns four noteworthy development trends by examining comprehensive data spanning the last decade from 100 NZEB and zero energy building.Further,a comprehensive analysis of essential technology advancements in line with these identified trends is performed.The issues and challenges arising from the increased application of renewable energy in the context of China's carbon peak and carbon neutrality goals have also been discussed.Finally,based on this analysis,the challenges and corresponding suggestions for future research directions were proposed to help guide future studies exploring emerging trends in the NZEB field.

A review on zero energy buildings-Pros and cons

Enhancing the energy efficiency of structures has been a staple of energy policies.The key goal is to slash elec-tricity usage in order to minimize the footprint of houses.This goal is sought by putting restrictions on the design specifications with respect to the properties of the raw materials and components as well as the exploitation of sustainable sources of energy.These facts for the basis for zero-energy building(ZEB)being established.This novel technology has faced several obstacles impeding its commercialization and future advancement.This inves-tigation therefore holistically explored and evaluated the state of zero energy building and factors impeding their commercialization.The review further proposed some suggestion in terms of technology that can be considered by the sector to augment existing technologies.Similarly,the investigation touched on the effect of occupant’s character in zero energy structures.Policies in terms of government subsidies and tax rebates were recommended to encourage more investors into the sector.Finally,the perception of zero energy building being more expensive compared to the traditional structures can equally be curbed via efficient and effective public sensitization.

Contribution of nearly-zero energy buildings standards enforcement to achieve carbon neutral in urban area by 2060

Nearly-zero energy buildings (NZEB) would effectively improve building energy efficiency and promote building electrification. By using a carbon emission model integrated into a bottom-up mid-to-long term energy consumption model, this study analyzes the contribution of NZEB standards to carbon emission targets in the urban area of China by 2060. Three scenarios are set, namely BAU, steady development (S1), and high-speed development (S2). For BAU, the total carbon emissions will reach a peak of 1.94 Gt CO_(2) by 2040. In S1 scenario, total building carbon emissions will reach the peak of 1.72 Gt CO_(2) by 2030. In S2 scenario, the carbon emissions will reach a peak by 2025 with 1.64 Gt CO_(2). Under S1 scenario, which features consistency with NZEB market development and periodic improvement of building energy-efficiency standards, the carbon emission peak in 2030 will be accomplished. To achieve carbon neutrality by 2060, the upgrading of building energy standards to NZEB will contribute 50.1%, while zero-carbon electricity contribution is 49.9%. It is concluded that 2025, 2030, and 2035 could be set as mandatory enforcement years for ultra-low energy buildings, NZEB and zero energy building (ZEB), respectively.

New challenges for optimal design of nearly/net zero energy buildings under post-occupancy performance-based design standards and a risk-benefit based solution

One of the challenges in construction of nearly and net ZEBs is how to truly achieve the nearly and net energy goals after building occupancy.Traditional building design standards and practices are mostly based on design performance evaluation,but practices show that many designed nearly/net ZEBs failed to achieve the energy goals after building occupancy.To facilitate the practical achievement of nearly and net ZEBs,recently most of the newly-released ZEB design standards have turned to post-occupancy performance evaluation,posing great challenges to nearly and net ZEB design.However,the detailed challenges have not be comprehensively investigated,and effective optimal design methods which can facilitate the achievement of nearly and net ZEBs under these standards are still absent.In this study,new challenges of nearly and net ZEB design under the post-occupancy performance-based design standards are fully investigated,and a risk-benefit based optimal design method is proposed to facilitate the achievement of nearly and net ZEBs under these standards.The newly-released ZEB standard in China is taken as an example to investigate the challenges and test the proposed method.Results show that nearly and net ZEBs designed using conventional design method have high risk in achieving energy goals under these standards due to high risk in satisfying the requirement regarding non-renewable primary energy consumption after building occupancy.The proposed design method is effective to facilitate achieving energy goals under these standards based on the risk that decision-makers would like to take.

Comprehensive energy, economic, environmental assessment of a building integrated photovoltaic-thermoelectric system with battery storage for net zero energy building

To realize the goal of net zero energy building(NZEB),the integration of renewable energy and novel design of buildings is needed.The paths of energy demand reduction and additional energy supply with renewables are separated.In this study,those two are merged into one integration.The concept is based on the combination of photovoltaic,thermoelectric modules,energy storage and control algorithms.Five types of building envelope systems,namely PV+TE(S1),Grid+TE(S2),PV+Grid+TE(S3),PV+Battery+TE(S4)and PV+Grid+Battery+TE(S5)are studied,from aspects of energy,economic and environmental(E3)performance.The new envelope systems can achieve thermal load reduction while providing additional cooling/heating supply,which can promote advance of NZEBs.It is found that there is a typical optimum setting of thermal energy load for each one of them with minimum annual power consumption.Except for the S1 system,the rest can realize negative accumulated power consumption in a year-round operation,which means the thermal load of building envelope could be zero.The uniform annual cost for S1 to S5 under interest rate of 0.04 are 19.78,14.77,23.83,60.53,64.94$/m2,respectively.The S5 system has the highest environmental effect with 3.04 t/m2 reduction of CO_(2) over 30 years of operation.

New Building Typologies for Zero Energy Mass Custom Housing(ZEMCH)in More Sustainable Patterns of Development

Conferences and publications on Smart Cities and self-styled ecological buildings such as“Vertical Forests”,“Biophilic”building complexes and other similar are multiplying.But then,in reality,we continue to design as we have always done for the last ninety years:with the consolidated rules and formal solutions of international post-modern composition,in its various forms.The only attentions are(and not always)to super-insulate the envelopes,arrange photovoltaic panels on the roofs,make the systems smart and cover the facades and roofs with appropriate green washing.Even in the awareness that human settlements and cities are extremely complex phenomena,mostly determined by economic and social factors,rather than by conscious typological-settlement choices,perhaps the time has come to acknowledge that the traditional paradigms of design must be changed.First of all,the types of settlements must be renewed,because it is through their optimization that the greatest savings in terms of energy and sustainability can be achieved.The research presented here is the application of a ten-year study that involved the development of net Zero Energy Mass Custom Housing(ZEMCH)in specific context in southern Italy.The Innovation and Transparency of Tenders Environmental Compatibility(ITACA)Assessment Protocol,derived from the Green Building Challenge’s GBTool,was used as a design guide,which is normally used for the assessment and judgment of sustainability at the building scale and not of the urban design.The result is a settlement model in which network of pedestrian,cycle and public transport is fully integrated with adjacent urban areas;effective landscaping connects public and private green and kitchen-gardens/orchards everywhere;buildings are made with new semi-underground typologies;net ZEMCHs are made with local,recyclable materials with low impact or positive energy balance;wastewater and rainwater are collected,in-loco phyto-purified and reused;renewable energies(sun,earth,wind)satisfy remaining necessities,with a minimum of plant interventions.

Zero Energy Hotels and Sustainable Mobility in the Islands of Aegean Sea (Greece)

The goal of this work is to evaluate and to give evidence to innovative and sustainable technologies applied in the construction industry to carry out self-sufficient energy and to use the surplus energy for the production of hydrogen vector. An architectural integration design along with high technological systems is performed. The intermittency of renewable energy sources along with climatic conditions dependency imposes to store the energy produced, since it is clean and having a big calorific value: the hydrogen vector is currently the better energy carrier. The energy to obtain hydrogen by dissociation of water is supplied by a photovoltaic (PV) system. Through the computations of the annual energy balance between building’s demand and supply energy, it is shown that the extra energy produced by the solar generation system is used also for the hydrogen sustainable mobility. The renewable systems, model’s design and case study are tackled for the bigger one of the Dodecanese islands in the South Aegean Sea: Rhodes (Rodos). The Zero energy building’s integrative design-based approach, applied to the Hotel Buildings type industry is targeted to have new hotels buildings, in the Mediterranean typical warm climate, with zero energy consumption. The designers, authors of this work, have studied a real case or pilot project of an hotel, in the resort formula, suitable to the Greek landscape, showcasing technologies and innovations supporting environmental sustainability, energy efficiency, use of renewable energy, electricity storage by fuel cells that are tools particularly applicable to hotel facility [1]. The feasibility of this case study or pilot project is aligned jointly to the target of Zero Emission and Energy Efficiency EU Policy, as imposed by EU Directives. The strategic position of Rhodes in a geographical point full of sun and wind renewable energy power, enables to ensure the clean energy production, the current interesting development of the hydrogen as energy vector in the buildings [2] and also to satisfy the demand of tourists’ accommodation by having at the same time zero energy costs. Moreover, the presence in the island of the best example worldwide of ancient and sustainable built environment (UNESCO World Heritage site), represents also the best motivation to give witness there of a zero impact environmental urban development through the adoption of these achieved scientific results for a major success of Zero Energy Buildings.

MOHAWK COLLEGE’S NET ZERO ENERGY AND ZERO CARBON BUILDING-A LIVING LAB FOR HIGH EFFICIENCY AND RENEWABLE ENERGY TECHNOLOGIES IN BUILDINGS

In recent years,large high efficiency and Net-Zero Energy Buildings(NZEB)are becoming a reality that are setting construction and energy benchmarks for the industry.As part of this significant effort,in 2018,Mohawk College opened the 8,981 m^(2)(96,670 ft2)Joyce Centre for Partnership and Innovation(JCPI)building in Hamilton,Ontario;becoming Canada’s largest NZEB and zero-carbon institutional facility.The building integrated a high-efficiency design,construction materials,and technologies;as well as renewable energy technologies to significantly reduce its annual energy consumption and greenhouse gas emissions.Furthermore,the JCPI building was also designed as a living lab where students,faculty,researchers and industry are able to monitor and validate the performance of this state-of-the-art facility.The building was designed to have an energy use intensity of 73 kWh/m^(2)·year(0.26 GJ/m^(2)·year);hence,potentially consuming approximately 80%less energy than the average educational service building in Ontario.This paper gives an overview of the design criteria and technologies that were considered to achieve this innova-tive building.

INFLUENCING PARAMETERS OF THE LIFE CYCLE COST-ENERGY RELATIONSHIP OF BUILDINGS

Buildings contribute around 45%of the world’s energy consumption.Reducing energy demand in buildings therefore plays a vital role in addressing the depletion of energy resources and associated environmental issues.Previous research explored the optimisations of the costs and energy consumption of buildings,but often overlooked the connections,tradeoffs and synergies between them.Th e aim of this paper is thus to develop a theoretical model of the influencing parameters of the life cycle cost-energy relationship(LCCER)of buildings using the Political,Economic,Sociocultural,Technological,Environmental and Legal(PESTEL)analytical framework. is study was carried out through a critical literature review,model development and validation through case studies with four zero or nearly zero energy building projects carefully selected from the European Union and Australia.Th e developed model addresses the buildings’LCCER by identifying the key influencing parameters and explicating the mechanisms(namely,the simultaneous and unilateral effects)by which the identified parameters affect such relationship.Th e important influencing parameters were found to reside in two aspects:(1)internal project designs covering building characteristics,building structure and function,and construction process,and(2)external environments covering climate,economic condition,occupant behaviour,policy and regulation,and buildings’lifespan focused in the studies.Various statistical correlations were found to exist between the costs and energy consumption of the studied cases.It is summarised that these correlations may be attributable to the synergy between the simultaneous and unilateral effects of the identified parameters.Th e developed model contributes a systemic approach to examining the building’s life cycle economics and energy in a comparative manner.

Indoor environment of nearly zero energy residential buildings with conventional air conditioning in hot-summer and cold-winter zone

According to the few researches on Nearly zero energy residential buildings(NZERB)in hot-summer and cold-winter zone,although it could reduce the cooling load of buildings due to its high thermal insulation and air tightness,it still needed for certain cooling in summer.This paper studied indoor environment of NZERB un-der three kinds of air-conditioners(split-type air-conditioner,multi-line air-conditioner and ceiling radiant air-conditioner).Firstly,a simulation model of NZERB was established based on Nanjing,a typical city in hot-summer and cold-winter zone.Secondly,variation of indoor air temperature and building load characteristics with outdoor air temperature were studied.Thirdly,indoor environment and energy consumption under three selected con-ventional air-conditioners in summer were simulated.Finally,the discussion was given,and an air-conditioner combining with convective and radiant cooling were proposed.The results indicated that the air-conditioner needed to be turned on in NZERB in hot-summer and cold-winter zone due to the room air temperature in off-air condition ranged from 32℃to 36℃,which was higher than designed indoor environment temperature in sum-mer,but the indoor environment of NZERB under three selected conventional air-conditioners could not meet the requirements of energy saving and comfort at the same time,and a proposed convective-radiant air-conditioner could be fast,stable,and energy saving.The findings can provide a reference for conducting active technology in NZERB.

One Year Minergie-A--Switzerlands Big Step towards Net ZEB

The first available label standardizing a zero-balanced type of building is the Swiss Standard Minergie-A. The standard prescribes an annual net zero primary energy balance for heating, domestic hot water and ventilation. Electricity consumption for appliances and lighting is excluded. Additionally, Minergie-A is the first standard worldwide which includes a requirement in regard to embodied energy. Based on an analysis of 39 Minergie-A buildings, this paper shows that a wide range of different energy concepts and embodied energy strategies are possible in the scope of the label. The basis of all Minergie-A buildings is a well-insulated building envelope. However, the step from the Swiss Standard Minergie-A to a Net ZEB （net zero energy building） standard which includes electricity consumption for appliances and lighting is not a very big one. Increasing the size of the photovoltaic system is sufficient in most cases. Anyway, some of the Minergie-A buildings evaluated are also Net ZEBs. In this paper, it is also shown that the net zero balance during the operational phase of Net ZEBs clearly outweighs the increased embodied energy for additional materials in a life cycle energy analysis.

Prospects of shallow geothermal systems in HVAC for NZEB

Shallow geothermal systems use the thermal inertia of the earth to provide a temperature gradient between the ambient conditions and the underground soil.This thermal inertia can be used by the heat exchangers to provide space heating and cooling during the winters and summers.This paper provides a brief but broad overview of the different active and passive technologies involved in the use of heat exchangers for HVAC in order to achieve a near net zero energy building.Firstly the different types of ground heat exchangers and heat pumps are introduced along with the relevant studies of significance in this field.It has been demonstrated that the different types of heat exchangers can be integrated with thermally active building envelopes and renewable energy resources to significantly minimize the building energy use.Finally a pathway has been devised for use of ground heat exchangers to realize a net zero energy building.