Energy Performance of SOFC Cogeneration System for Residential Buildings in Chinese Cold Areas

2014 ◽  
Vol 935 ◽  
pp. 48-51
Author(s):  
Xin Zhi Gong ◽  
Yasunori Akashi ◽  
Daisuke Sumiyoshi
Keyword(s):  
Thermal Energy ◽  
Energy Efficient ◽  
Energy Demand ◽  
Residential Buildings ◽  
Reduction Rate ◽  
Energy Performance ◽  
Primary Energy ◽  
Beijing City ◽  
Primary Energy Demand ◽  
Cogeneration System

Primary energy reduction and energy efficiency improvement are important targets to be achieved in every society and in residential buildings in particular. An energy-efficient and low-emissions solid oxide fuel cell (SOFC) cogeneration system is a promising electric and thermal energy generation technology for implementation in future residential buildings. This paper aims to analyze the energy performance in terms of primary energy demand and its reduction rate when SOFC cogeneration system is used in residential buildings. This study outlines SOFC cogeneration system and its simulation method, and then develops a standard family model for simulation under cold weather condition in China and selected Beijing city as an example, and finally compares them with traditional power and heat generation system based on gas and electricity. The results show that SOFC cogeneration system is an energy-efficient alternative power and thermal energy cogeneration technology for cold climatic cities such as Beijing, and can offer a large reduction rate (about 15.8% in winter) of primary energy demand in residential buildings. This study also finds that the significant reductions in primary energy demand of SOFC system result for the periods with air temperature decreasing.

scholarly journals Nearly Zero Energy Standard for Non-Residential Buildings with High Energy Demands—An Empirical Case Study Using the State Related Properties of Bavaria

2017 ◽  
Author(s):  
Michael Keltsch ◽  
Werner Lang ◽  
Thomas Auer
Keyword(s):  
Energy Demand ◽  
Energy Savings ◽  
Residential Buildings ◽  
Energy Performance ◽  
High Energy ◽  
Primary Energy ◽  
The State ◽  
Zero Energy ◽  
Primary Energy Demand ◽  
New Buildings

The Energy Performance of Buildings Directive 2010 calls for the Nearly Zero Energy Standard for new buildings from 2021 onwards: Buildings using “almost no energy” are powered by renewable sources or energy produced by the building itself. For residential buildings, this ambitious new standard has already been reached. But for other building types this goal is still far away. The potential of these buildings to meet a Nearly Zero Energy Standard was investigated by analyzing ten case studies representing non-residential buildings with different uses. The analysis shows that the primary characteristics common to critical building types are a dense building context with a very high degree of technical installation (such as hospital, research and laboratory buildings). The large primary energy demand of these types of buildings cannot be compensated by building and property-related energy generation including off-site renewables. If the future Nearly Zero Energy Standard were to be defined with lower requirements because of this, the state related properties of Bavaria suggest that the real potential energy savings available in at least 85% of all new buildings would be insufficiently exploited. Therefore, it would be useful to instead individualize the legal energy verification process for new buildings to distinguish critical building types such as laboratories and hospitals.

scholarly journals Nearly Zero Energy Standard for Non-Residential Buildings with High Energy Demands—An Empirical Case Study Using the State Related Properties of Bavaria

2017 ◽  
Author(s):  
Michael Keltsch ◽  
Werner Lang ◽  
Thomas Auer
Keyword(s):  
Energy Demand ◽  
Energy Savings ◽  
Residential Buildings ◽  
Energy Performance ◽  
High Energy ◽  
Primary Energy ◽  
The State ◽  
Zero Energy ◽  
Primary Energy Demand ◽  
New Buildings

The Energy Performance of Buildings Directive 2010 calls for the Nearly Zero Energy Standard for new buildings from 2021 onwards: Buildings using “almost no energy” are powered by renewable sources or energy produced by the building itself. For residential buildings, this ambitious new standard has already been reached. But for other building types this goal is still far away. The potential of these buildings to meet a Nearly Zero Energy Standard was investigated by analyzing ten case studies representing non-residential buildings with different uses. The analysis shows that the primary characteristics common to critical building types are a dense building context with a very high degree of technical installation (such as hospital, research and laboratory buildings). The large primary energy demand of these types of buildings cannot be compensated by building and property-related energy generation including off-site renewables. If the future Nearly Zero Energy Standard were to be defined with lower requirements because of this, the state related properties of Bavaria suggest that the real potential energy savings available in at least 85% of all new buildings would be insufficiently exploited. Therefore, it would be useful to instead individualize the legal energy verification process for new buildings to distinguish critical building types such as laboratories and hospitals.

scholarly journals THE INFLUENCE OF SCHEDULES OF OPEN OFFICE OCCUPANTS’ PRESENCE ON BUILDING’S ENERGY DEMAND

2020 ◽  
Author(s):  
Jonas Bielskus ◽  
Violeta Motuzienė
Keyword(s):  
Energy Efficient ◽  
Energy Demand ◽  
Energy Performance ◽  
Primary Energy ◽  
Simulation Software ◽  
Design Stage ◽  
Sustainable Buildings ◽  
Standard Case ◽  
Primary Energy Demand ◽  
Performance Calculation

Many studies show, that there is a difference between actual and design energy consumption in energy efficient and sustainable buildings. As a rule, buildings consume more energy than it has been foreseen at the design stage. Occupants’ behaviour in buildings is also identified as one of the main reasons causing the so called Performance Gap. Having mobile workstations, opened plan offices are becoming more popular in design solutions in sustainable buildings. Here we have studied one of such office spaces. Monitoring of real occupancy was performed and real occupation schedules were statistically generated. The schedules were compared to the ones given by European Standard for energy performance calculation as well as with default schedules proposed by simulation software DesignBuilder. The comparison shows a significantly lower measured occupancy compared to the above-mentioned schedules. To compare the influence of occupancy related assumptions on predicted energy demand, DesignBuilder model was created and simulated for 3 different occupancy schedules. The results have shown that primary energy demand of a building due to assumptions related with an occupancy, compared to default DesignBuilder schedules are: 111 kWh/m² (32%) higher than the standard case and 152 kWh/m² (44%) than the actual one.

scholarly journals The influence of crop dryer operation parameters on the efficiency of energy recovery from extract air

2019 ◽  
Vol 116 ◽  
pp. 00064
Author(s):  
Edward Przydróżny ◽  
Aleksandra Przydróżna ◽  
Sylwia Szczęśniak ◽  
Juliusz Walaszczyk
Keyword(s):  
Air Temperature ◽  
Thermal Energy ◽  
Energy Demand ◽  
Energy Recovery ◽  
Primary Energy ◽  
Specific Humidity ◽  
Primary Energy Demand ◽  
Air Temperatures ◽  
Flow Surface ◽  
Recovery System

Crop drying, especially maize drying, occurs at low external air temperatures, which are lower than the extract air temperature. Therefore, using heat exchangers, to recover thermal energy from the extract air to preheat the cold and dry external air, results in a significant reduction in the primary energy demand for crop drying. The measurements of air parameters in the crop dryer, with a drying capacity of 19 Mg/h of maize, confirm the assumptions undertaken for the production of the heat recovery system. We apply the cross-counter-flow surface heat exchanger system to provide a significant improvement in the efficiency of crop drying. We perform the analysis of the thermal energy recovery system operation. Our results indicate the influence of the drying air set-point and the crop specific humidity on the efficiency of energy recovery from the exhaust air. We performed our measurements at different drying air temperature set-points and different crop relative humidity.

scholarly journals Analysis of the Effects of Strengthening Building Energy Policy on Multifamily Residential Buildings in South Korea

2020 ◽  
Vol 12 (9) ◽  
pp. 3566
Author(s):  
Byung Chang Kwag ◽  
Sanghee Han ◽  
Gil Tae Kim ◽  
Beobjeon Kim ◽  
Jong Yeob Kim
Keyword(s):  
Energy Consumption ◽  
South Korea ◽  
Energy Policy ◽  
Energy Demand ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Primary Energy ◽  
Building Envelope ◽  
Primary Energy Consumption

The purposes of this study were to overview the building-energy policy and regulations in South Korea to achieve energy-efficient multifamily residential buildings and analyze the effects of strengthening the building design requirements on their energy performances. The building energy demand intensity showed a linear relationship with the area-weighted average U-values of the building envelope. However, improving the thermal properties of the building envelope was limited to reducing the building-energy demand intensity. In this study, the effects of various energy conservation measures (ECMs) on the building-energy performance were compared. Among the various ECMs, improving the boiler efficiency was found to be the most efficient measure for reducing the building-energy consumption in comparison to other ECMs, whereas the building envelope showed the least impact, because the current U-values are low. However, in terms of the primary energy consumption, the most efficient ECM was the lighting power density because of the different energy sources used by various ECMs and the different conversion factors used to calculate the primary energy consumption based on the source type. This study showed a direction for updating the building-energy policy and regulations, as well as the potential of implementing ECMs, to improve the energy performances of Korean multifamily residential buildings.

scholarly journals Hybrid Cascade Heat Pump and Thermal-Electric Energy Storage System for Residential Buildings: Experimental Testing and Performance Analysis

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2580
Author(s):  
Valeria Palomba ◽  
Antonino Bonanno ◽  
Giovanni Brunaccini ◽  
Davide Aloisio ◽  
Francesco Sergi ◽  
...  
Keyword(s):  
Heat Pump ◽  
Energy Demand ◽  
Experimental Testing ◽  
Residential Buildings ◽  
Storage System ◽  
Electric Energy ◽  
Energy Storage System ◽  
Primary Energy ◽  
Electric Energy Storage ◽  
Primary Energy Demand

The need for innovative heating and cooling systems to decarbonize the building sector is widely recognized. It is especially important to increase the share of renewables at building level by maximizing self-consumption and reducing the primary energy demand. Accordingly, in the present paper, the results on a wide experimental campaign on a hybrid system are discussed. The system included a sorption module working as the topping cycle in a cascade configuration with a DC-driven vapor compression heat pump. A three-fluids heat exchanger with a phase change material (PCM), i.e., RT4 with nominal melting temperature of 4 °C, was installed on the evaporator side of the heat pump, for simultaneous operation as thermal storage and heat pumping purposes. The heat pump was connected to a DC-bus that included PV connection and electricity storage (batteries). Results showed that the energy efficiency of the heat pump in cascade operation was double compared to compression-only configuration and that, when simultaneously charging and discharging the latent storage in cascade configuration, no penalization in terms of efficiency compared to the compression-only configuration was measured. The self-sufficiency of the system was evaluated for three reference weeks in summer conditions of Athens climate and it was found that up to 100% of the electricity needed to drive the system could be self-produced for a modest cooling demand and up to 67% for the warmer conditions with high cooling demand.

scholarly journals Towards an Automated, Fast and Interpretable Estimation Model of Heating Energy Demand: A Data-Driven Approach Exploiting Building Energy Certificates

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1273 ◽  
Author(s):  
Antonio Attanasio ◽  
Marco Piscitelli ◽  
Silvia Chiusano ◽  
Alfonso Capozzoli ◽  
Tania Cerquitelli
Keyword(s):  
Decision Tree ◽  
Energy Demand ◽  
Building Energy ◽  
Energy Performance ◽  
Primary Energy ◽  
Machine Learning Algorithms ◽  
Data Driven ◽  
Support Vector ◽  
Estimation Model ◽  
Primary Energy Demand

Energy performance certification is an important tool for the assessment and improvement of energy efficiency in buildings. In this context, estimating building energy demand also in a quick and reliable way, for different combinations of building features, is a key issue for architects and engineers who wish, for example, to benchmark the performance of a stock of buildings or optimise a refurbishment strategy. This paper proposes a methodology for (i) the automatic estimation of the building Primary Energy Demand for space heating ( P E D h ) and (ii) the characterization of the relationship between the P E D h value and the main building features reported by Energy Performance Certificates (EPCs). The proposed methodology relies on a two-layer approach and was developed on a database of almost 90,000 EPCs of flats in the Piedmont region of Italy. First, the classification layer estimates the segment of energy demand for a flat. Then, the regression layer estimates the P E D h value for the same flat. A different regression model is built for each segment of energy demand. Four different machine learning algorithms (Decision Tree, Support Vector Machine, Random Forest, Artificial Neural Network) are used and compared in both layers. Compared to the current state-of-the-art, this paper brings a contribution in the use of data mining techniques for the asset rating of building performance, introducing a novel approach based on the use of independent data-driven models. Such configuration makes the methodology flexible and adaptable to different EPCs datasets. Experimental results demonstrate that the proposed methodology can estimate the energy demand with reasonable errors, using a small set of building features. Moreover, the use of Decision Tree algorithm enables a concise interpretation of the quantitative rules used for the estimation of the energy demand. The methodology can be useful during both designing and refurbishment of buildings, to quickly estimate the expected building energy demand and set credible targets for improving performance.

scholarly journals Investigation of the BNB Building Certification for the Further Development of the Energy Performance Certificate

2021 ◽  
Vol 2069 (1) ◽  
pp. 012233
Author(s):  
Manuela Walsdorf-Maul ◽  
Laura Dommack ◽  
Michael Schneider
Keyword(s):  
Life Cycle ◽  
Energy Demand ◽  
Energy Performance ◽  
Primary Energy ◽  
Assessment System ◽  
Technical Quality ◽  
Primary Energy Demand ◽  
German Speaking ◽  
Environmentally Sound ◽  
Further Development

Abstract In this study, a life cycle oriented planning of buildings is proposed to support future building developers and planners in making environmentally sound decisions on the basis of comprehensive information. The study, in which the building certification BNB (Bewertungssystem Nachhaltiges Bauen, or “Assessment System for Sustainable Building”) is carried out on the example of an office building, is applicable to German-speaking countries. In addition to meeting the requirements of the 2020 German Energy Act for Buildings (GebäudeEnergieGesetz, GEG), the aim is to optimize the building with regard to sustainability criteria of the BNB by revising and expanding the existing planning so that the “gold” quality label can eventually be achieved. The biggest influence on this optimization process is, among other things, the life cycle costs, the adaptability of the building, the primary energy demand as well as the technical quality. Based on these findings, this research paper details the further development of the energy performance certificate, before in a final step the building assessment can be graphically presented with regard to both aspects – energy efficiency (final energy) and sustainability (in terms of ecological, economic, socio-cultural, functional and technical quality, process quality and location characteristics) – from the production phase through the usage phase up to the disposal phase.

scholarly journals Decarbonization of Residential Building Energy Supply: Impact of Cogeneration System Performance on Energy, Environment, and Economics

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2538
Author(s):  
Praveen K. Cheekatamarla
Keyword(s):  
Carbon Dioxide ◽  
Power Generation ◽  
Energy Consumption ◽  
Carbon Footprint ◽  
Residential Buildings ◽  
Building Energy ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Cogeneration System ◽  
The Impact

Electrical and thermal loads of residential buildings present a unique opportunity for onsite power generation, and concomitant thermal energy generation, storage, and utilization, to decrease primary energy consumption and carbon dioxide intensity. This approach also improves resiliency and ability to address peak load burden effectively. Demand response programs and grid-interactive buildings are also essential to meet the energy needs of the 21st century while addressing climate impact. Given the significance of the scale of building energy consumption, this study investigates how cogeneration systems influence the primary energy consumption and carbon footprint in residential buildings. The impact of onsite power generation capacity, its electrical and thermal efficiency, and its cost, on total primary energy consumption, equivalent carbon dioxide emissions, operating expenditure, and, most importantly, thermal and electrical energy balance, is presented. The conditions at which a cogeneration approach loses its advantage as an energy efficient residential resource are identified as a function of electrical grid’s carbon footprint and primary energy efficiency. Compared to a heat pump heating system with a coefficient of performance (COP) of three, a 0.5 kW cogeneration system with 40% electrical efficiency is shown to lose its environmental benefit if the electrical grid’s carbon dioxide intensity falls below 0.4 kg CO2 per kWh electricity.

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