Towards zero-energy residential complexes in high-density conditions

2020 ◽  
pp. 1420326X2096216
Author(s):  
Olga Kolodiy ◽  
Guedi Capeluto

Carbon dioxide is the largest component of the human footprint and one of the major components of all greenhouse gases. The expected increase in population will lead to growth in energy consumption and greenhouse gas emissions. The building industry has the highest potential for reducing greenhouse gas emissions. Therefore, buildings should become not only efficient consumers but also energy producers, not a simple task in dense cities. The paper describes the feasibility and limitations of near zero energy design in highly dense urban conditions. The study was carried out by examination and comparison of various density design, alternatives of an existing urban plot in the coastal climate zone of Israel. Increased dwelling units’ number leads to higher total energy use on the one hand and mutual shading of new high-rise residential buildings on the other. Preserving solar rights for PV systems installation become more complex. The relation between urban density and solar rights in urban design, energy consumption and energy generation within plot borders and their implications are presented and discussed in the paper.

2020 ◽  
Vol 82 (12) ◽  
pp. 2745-2760
Author(s):  
Iliana Cardenes ◽  
Afreen Siddiqi ◽  
Mohammad Mortazavi Naeini ◽  
Jim W. Hall

Abstract A large part of operating costs in urban water supply networks is usually due to energy use, mostly in the form of electricity consumption. There is growing pressure to reduce energy use to help save operational costs and reduce carbon emissions. However, in practice, reducing these costs has proved to be challenging because of the complexity of the systems. Indeed, many water utilities have concluded that they cannot practically achieve further energy savings in the operation of their water supply systems. This study shows how a hybrid linear and multi-objective optimization approach can be used to identify key energy consumption elements in a water supply system, and then evaluate the amount of investment needed to achieve significant operational gains at those points in the supply network. In application to the water supply system for the city of London, the method has shown that up to 18% savings in daily energy consumption are achievable. The optimal results are sensitive to discount rate and the financial value placed on greenhouse gas emissions. Valuation of greenhouse gas emissions is necessary to incentivise high levels of energy efficiency. The methodology can be used to inform planning and investment decisions, with specific focus on reducing energy consumption, for existing urban water supply systems.


2021 ◽  
Vol 117 (2) ◽  
pp. 1
Author(s):  
Seyed Saeed HOSSEINI ◽  
Hassan FEIZI ◽  
Hamed KAVEH ◽  
Hossein SAHABI

With the aim of evaluation and comparison of the greenhouse gas emissions from soybean and tangerine production in Golestan province, Iran, a pilot experiment was carried out. In this experiment, 43 fields of soybeans and 43 orchard tangerines were selected by various management in the province using questionnaires. The greenhouse gas emissions were examined using the Global Warming Potential (GWP). The results of this study showed that fossil fuel was the highest energy consumption in the production of soybeans (6906.5 MJ ha-1) and tangerines (17205.1 MJ ha-1). The lowest amount of energy consumption among inputs was related to micro fertilizers, that was 9 MJ ha-1 for soybeans and 17.6 MJ ha-1 for tangerine. In both of production system, the most energy consumed was shown for the harvesting sector. Irrigation and planting were the highest contributors to greenhouse gas emissions in soybean field by 387.7 and 109.4 kg CO2 ha-1, respectively; while in the tangerine production, the most greenhouse gas emissions were related to irrigation and harvesting process by 5828.4 and 394.7 kg CO2 ha-1. In general, input energy in soybean and tangerine were 17512.8 and 33879.8 MJ ha-1, total output energy was calculated 48310.5 and 105463 MJ ha-1. Finally, the energy use efficiency was computed for soybean and tangerine 2.9 and 3.3, respectively.


2019 ◽  
Vol 11 (22) ◽  
pp. 6482
Author(s):  
Katerina Sojkova ◽  
Martin Volf ◽  
Antonin Lupisek ◽  
Roman Bolliger ◽  
Tomas Vachal

Energy retrofitting of existing building stock has significant potential for the reduction of energy consumption and greenhouse gas emissions. Roughly half of the CO2 emissions from Czech building stock are estimated to be allocated to residential buildings. Approximately one-third of the Czech residential building stock have already been retrofitted, but retrofitting mostly takes place in large cities due to greater income. A favourable concept for the mass retrofitting of residential building stock, affordable even in low-income regions, was of interest. For a reference building, multi-criteria assessment of numerous retrofitting measures was performed. The calculation involved different building elements, materials, solutions, and energy-efficiency levels in combination with various heating systems. The assessment comprised environmental impact, represented by operational and embodied primary energy consumption and greenhouse gas emissions, and investment and operational costs using the annuity method. Analysis resulted in the identification of favourable retrofitting measures and showed that complex building retrofitting is advantageous from both a cost and an environmental point of view. The environmental burden could be decreased by approximately 10–30% even without photovoltaic installation, and costs per year could be decreased by around 40%.


Buildings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 99
Author(s):  
Björn Berggren ◽  
Maria Wall

One of the greatest challenges for the world today is the reduction of greenhouse gas emissions. As buildings contribute to almost a quarter of the greenhouse gas emissions worldwide, reducing the energy use of the existing building stock is an important measure for climate change mitigation. In order to increase the renovation pace, there is a need for a comprehensive technical documentation that describes different types of buildings in the existing building stock. The purpose of this study is to analyse and describe existing residential buildings in Sweden. The data are based on published reports from 1967 to 1994 that have not been publicly available in a database for other researchers to study until now. Data from the reports have been transferred to a database and analysed to create a reference for buildings and/or a description of building typology in Sweden. This study found that there is a rather large homogeneity in the existing residential building stock. However, it is not possible to use a single reference building or building technique to cover the majority of the existing buildings. In Sweden, common constructions for exterior walls in multi-dwelling buildings which should be used for further studies are insulated wood infill walls with clay brick façades, lightweight concrete walls with rendered façades and concrete sandwich walls. The most common constructions for one- and two-dwelling buildings are insulated wooden walls with clay brick façades or wooden façades. Furthermore, roof constructions with insulated tie beam and roof constructions where the tie beam is a part of the interior floor slab are frequently used and should be included in further studies.


2020 ◽  
Vol 81 (6) ◽  
pp. 1283-1295
Author(s):  
Iliana Cardenes ◽  
Jim W. Hall ◽  
Nick Eyre ◽  
Aman Majid ◽  
Simon Jarvis

Abstract Regulations to ensure adequate wastewater treatment are becoming more stringent as the negative effects of different pollutants on human health and the environment are understood. However, treatment of wastewater to remove pollutants is energy intensive, so has added significantly to the operation costs of wastewater treatment plants. Analysis from six of the largest wastewater treatment works in South East England reveals that the energy consumption of these treatment works has doubled in the last five years due to expansions to meet increasingly stringent effluent standards and population growth. This study quantifies the relationship between energy use for wastewater treatment and four measures of pollution in effluents from UK wastewater treatment works (biochemical oxygen demand, ammoniacal nitrogen, chemical oxygen demand and suspended solids). The linear regression results show that indicators of these pollutants in effluents, together with the extension of plants to improve wastewater treatment, can predict over 95% of energy consumption. Secondly, using scenarios, the energy consumption and greenhouse gas emissions of effluent quality standards are estimated. The study finds that tightening effluent standards to increase water quality could result in a doubling of electricity consumption and an increase of between 1.29 and 2.30 additional MTCO2 per year from treating wastewater in large works in the UK.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Muhammad Imran ◽  
Orhan Ozcatalbas

AbstractThis study aimed to model energy use, energy efficiency, and greenhouse gas emissions in rain-fed wheat production by using a nonparametric data envelopment analysis (DEA) method. Data were collected through face-to-face interviews with 140 wheat farmers in 4 districts of Antalya Province. The energy inputs (independent variables) were human labor, seeds, chemical fertilizers, herbicides, and diesel fuel, and the energy output was the dependent variable. The results showed that the average energy consumption and the output energy for the studied wheat production system were 21. 07GJ ha−1 and 50. 99 GJ ha−1, respectively, and the total GHG emissions were calculated to be 592.12 kg CO2eq ha−1. Chemical fertilizer has the highest share of energy consumption and total GHG emissions. Based on the results from DEA, the technical efficiency of the farmers was found to be 0.81, while pure technical and scale efficiencies were 0.65 and 0.76, respectively. The results also highlighted that there is a potential opportunity to save approximately 14% (2.93 GJ ha−1) of the total energy consumption and consequently a 17% reduction in GHG emissions by following the optimal amounts of energy consumption while keeping the wheat yield constant. Efficient use of energy and reduction in GHG emissions will lead to resource efficiency and sustainable production, which is the main aim of the green economy.


2021 ◽  
Vol 17 (1) ◽  
pp. 1-16
Author(s):  
Asim Hasan ◽  
Rahil Akhtar Usmani

Rising greenhouse gas emissions is an important issue of the current time. India’s massive greenhouse gas emissions is ranked third globally. The escalating energy demand in the country has opened the gateway for further increase in emissions. Recent studies suggest strong nexus between energy consumption, economic growth, and carbon emissions. This study has the objective to empirically test the aforementioned interdependencies. The co-integration test and multivariate vector error correction model (VECM) are used for the analysis and the Granger Causality test is used to establish the direction of causality. The time-series data for the period of 1971–2011 is used for the analysis. The results of the study confirm strong co-integration between variables. The causality results show that economic growth exerts a causal influence on carbon emissions, energy consumption exerts a causal influence on economic growth, and carbon emissions exert a causal influence on economic growth. Based on the results, the study suggests a policy that focuses on energy conservation and gradual replacement of fossil fuels with renewable energy sources, which would be beneficial for the environment and the society.


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