Energy Consumption In Urban Areas Research Articles

Experience from Integrated Air Quality Management in the Mexico City Metropolitan Area and Singapore

More than half of the world’s population now lives in cities as a result of unprecedented urbanization during the second half of the 20th century. The urban population is projected to increase to 68% by 2050, with most of the increase occurring in Asia and Africa. Population growth and increased energy consumption in urban areas lead to high levels of atmospheric pollutants that harm human health, cause regional haze, damage crops, contribute to climate change, and ultimately threaten the society’s sustainability. This article reviews the air quality and compares the policies implemented in the Mexico City Metropolitan Area (MCMA) and Singapore and offers insights into the complexity of managing air pollution to protect public health and the environment. While the differences in the governance, economics, and culture of the two cities greatly influence the decision-making process, both have made much progress in reducing concentrations of harmful pollutants by implementing comprehensive integrated air quality management programs. The experience and the lessons learned from the MCMA and Singapore can be valuable for other urban centers, especially in the fast-growing Asia-Pacific region confronting similar air pollution problems.

Changes in energy and carbon intensity in Seoul’s water sector

The water sector accounts for a significant proportion of the total energy consumption in urban areas; therefore, that sector can contribute to energy transition in urban areas. Seoul, South Korea has promoted the use of renewable energy and sewer heat as part of city-wide energy transition efforts. This study built energy consumption inventories for the urban water cycle in Seoul for 2012 and 2015 and investigated changes in net energy intensity and corresponding net carbon intensity during that period. It found that Seoul’s energy transition efforts reduced net energy intensity in the water sector from 5.83 MJ/m3 in 2012 to 5.42 MJ/m3 in 2015, even with the increased use of energy-intensive advanced water treatment technology. In addition, this study estimated that about 8.52% of the water sector’s current energy consumption could be saved in 2020 if 18.4 million m3/year of water were reused and 2.40 million m3/year of rainwater were harvested. This study showed a way to extend energy transition efforts into the urban water sector by reducing energy demand through reducing water demand.

Quantifying city-scale emission responsibility based on input-output analysis – Insight from Tokyo, Japan

Cities play a crucial role in the implementation of carbon emission mitigation policies since most CO2 emissions are related to energy consumption in urban areas. Recent years, environmentally extended multi-regional input-output tables (EEMRIO) are emerged to reveal regional environment impact considering upstream supply chains crossing regional boundaries. However, city-scale MRIO has not been fully addressed since more focus has been located on national or prefectural level evaluation. For quantifying city-scale emission considering regional energy flow, we apply the input-output table of Tokyo to evaluate energy consumption at the city scale, and the results provides one of the the most detailed sector classification from a wide range of city emission studies. In Japan, Tokyo is considered to be representative of the contemporary Japanese urban energy structure, and its energy consumption and associated CO2 emissions are of major importance when making city-scale carbon mitigation policies. Here, domestic production for Tokyo and other regions is used to quantify the direct and indirect emissions arising from Tokyo final consumption. Our results are divided into sector-specific and fossil fuel source-specific (coal, crude oil, and natural gas) for both direct and indirect emissions. The major findings are as follows: (1) The transportation sector accounts for the largest share of direct emissions in Tokyo. (2) The energy supply, construction, private service sectors account for the largest share of indirect emissions in Tokyo. (3) There are three scopes of emission responsibility evaluated in this study: direct emission before allocation (BE) as 12.88 MtC, after allocation (AE) as 18.91 MtC, and the total including indirect emissions is 27.24 MtC, which is more than twice the direct emissions before allocation. The detailed and energy consumption and emission inventory may be essential for emission responsibility allocation to overcome geographical boundary, therefore, contributes to varied scales of carbon reduction policies.

Performance of an unglazed transpire collector in the facade of a building for heating and cooling in combination with a desiccant evaporative cooler

Abstract Refurbishment of energy inefficient buildings is an effective way of reducing energy consumption in urban areas. This can be done by taking advantage of the renewable energy sources available, mainly, solar energy. Desiccant evaporative cooling combined with unglazed transpired collectors, UTC's, allows covering the heating demand in the cold season and cooling demand in the hot season. UTC's can be installed on the facades of buildings, meeting a double goal: refurbishing the building exterior and providing heating and cooling to indoor spaces. In this paper, a model of this system was implemented using TRNSYS and the energy savings obtained were evaluated in different climatic conditions, different facade orientations and different building shapes. The objective was to find the best conditions to install this system and estimating the energy savings that can be reached, and its costs. The results showed that the reduction of heating demand was possible in all climatic conditions, weakly depending on the shape and orientation of the UTC facade installed. Cooling was also possible, but it depended more on the shape of the building. The higher energy savings were found for the linear shape buildings. Therefore, refurbishment using a UTC facade could be an interesting alternative for energy saving throughout the year in these cases.

Residential carbon dioxide emissions at the urban scale for county-level cities in China: A comparative study of nighttime light data

Abstract Carbon emissions from residential energy consumption in urban areas play a pivotal role in meeting emission targets. It is more beneficial to decomposing the emission reduction target to subnational units. This study aims to map urban residential carbon emissions at a finer spatial resolution to offer reference to disaggregating the carbon-reduction targets down to each sub-unit. With the launch of Suomi National Polar-orbiting Partnership (NPP) satellite, the day-night band of Visible Infrared Imaging Radiometer Suite (VIIRS) onboard represents a major advancement compared with Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) in terms of radiometric accuracy, spatial resolution and geometric quality. Therefore, the useful proxy was utilized to model the spatial distribution of residential carbon emissions at the urban scale for county-level cities in China. Firstly, the dynamic optimal threshold method was used to extract urban built-up areas based on NPP-VIIRS data and the statistical data. Secondly, comparison was conducted between the NPP-VIIRS data and both original and saturation-corrected DMSP-OLS data to explore the performance of NPP-VIIRS data. Finally, the spatial characteristics were analyzed in detail at the regional, provincial and prefectural level, respectively. The results show that the NPP-VIIRS data performed better in both statistic regression and spatial comparison. The spatial patterns indicated that there was an obvious north-south differentiation, especially the carbon emission density (defined as carbon emissions per grid), which was significantly higher in Northeastern China than that of other regions. The climate elements positively contributed to the increase of carbon emissions in residential sector, especially stimulating emissions related to building heating.

The End-use Electric Energy Consumption in Urban Areas: A GIS-based methodology. An application in the city of Naples.

This work is part of the scientific research sector concerning the Government of Urban and Territorial Transformations in order to promote efficiency and reduction of energy consumption in urban areas. The contribution proposes a further deepening of the research work already carried out under the project Pon Smart Energy Master by the research group of the Laboratory of Territory, Mobility and Environmental (TeMA Lab) of Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II. The aim is to assist public authorities, that also deal with the Urban Energy Governance, in determining the quantitative distribution of domestic and non-domestic electric energy consumption. Toward this goal, we use the Big Data, the Open Data and the Geographic Information System (GIS) techniques. In particular, this work developed a innovative GIS-based methodology that allows the knowledge, classification and representation of real electric energy consumption at micro scale for the domestic and non-domestic. Also, we validate the GIS-based methodology by an application at the city of Naples. We used the electric energy consumption data of year 2011 were given by Municipality Authority and Italian Revenue Agency. This will allow the identification of the electric energy problems present in the area of analysis in order to plan any intervention strategies. This contribution is divided into three main parts. In the first part, an analysis of the scientific literature is proposed on the theme of the Government of urban and territorial transformations and opportunities arising by Big Data, Open Data and GIS in the reduction of electric energy consumption. The second part explains the theoretical and technical phases that led to the development of the GIS-based methodology. In the last part, the application of the GIS-based methodology at the City of Naples is described.

Multiscale assessment of progress of electrification in Indonesia based on brightness level derived from nighttime satellite imagery.

Availability of electricity can be used as an indicator to proximate parameters related to human well-being. Overall, the electrification process in Indonesia has been accelerating in the past two decades. Unfortunately, monitoring the country's progress on its effort to provide wider access to electricity poses challenges due to inconsistency of data provided by each national bureau, and limited availability of information. This study attempts to provide a reliable measure by employing nighttime satellite imagery to observe and to map the progress of electrification within a duration of 20years, from 1993 to 2013. Brightness of 67,021 settlement-size points in 1993, 2003, and 2013 was assessed using data from DMSP/OLS instruments to study the electrification progress in the three service regions (Sumatera, Java-Bali, and East Indonesia) of the country's public electricity company, PLN. Observation of all service areas shows that the increase in brightness, which correspond with higher electricity development and consumption, has positive correlation with both population density (R2=0.70) and urban change (R2=0.79). Moreover, urban change has a stronger correlation with brightness, which is probably due to the high energy consumption in urban area per capita. This study also found that the brightness in Java-Bali region is very dominant, while the brightness in other areas has been lagging during the period of analysis. The slow development of electricity infrastructure, particularly in major parts of East Indonesia region, affects the low economic growth in some areas and formed vicious cycle.

User-integrated Innovations in Urban Areas for a Transition towards Sustainability

A continuing trend of global urbanization leads to a geographical concentration of population and social activities that causes a regional compression of concomitant resource and energy consumption. This paper argues that a Sustainable Living Lab infrastructure (SusLab) in urban areas facilitates a systematic integration of user’s consideration in the design and development of Product-Service Systems (PSS) that enables changes of daily routines in favor of urban wealth development and conservation of ecosystem services. The authors build on the Sustainable Consumption and Production (SCP) Model of the Wuppertal Institute that provides a theoretical framework of sociotechnical rearrangements towards urban sustainability transition. Therefore, a reconfiguration of social practices and PSS in a desired direction according to social, ecological and economic concerns is reconsidered on the micro level in line with efficiency, consistency, and sufficiency strategies. The authors introduce an assessment framework for urban sustainable development and illustrate multifarious concepts of PSS that are aiming to decouple wealth development from resource and energy consumption in urban areas.

Reduction of errors when estimating emissions based on static traffic model outputs

The rapid growth of traffic congestion has led to an increased level of emissions and energy consumption in urban areas. Well designed infrastructure and traffic controllers along with more efficie ...

Estimation of the building energy use intensity in the urban scale by integrating GIS and big data technology

Buildings are the major source of energy consumption in urban areas. Accurate modeling and forecasting of the building energy use intensity (EUI) in the urban scale have many important applications, such as energy benchmarking and urban energy infrastructure planning. The use of Big Data technology is expected to have the capability of integrating a large number of predictors and giving an accurate prediction of the energy use intensity of buildings in the urban scale. However, past research has often used Big Data technology in estimating energy consumption of a single building rather than the urban scale, due to several challenges such as data collection and feature engineering. This paper therefore proposes a geographic information system integrated data mining methodology framework for estimating the building EUI in the urban scale, including preprocessing, feature selection, and algorithm optimization. Based on 216 prepared features, a case study on estimating the site EUI of 3640 multi-family residential buildings in New York City, was tested and validated using the proposed methodology framework. A comparative study on the feature selection strategies and the commonly used regression algorithms was also included in the case study. The results show that the framework was able to help produce lower estimation errors than previous research, and the model built by the Support Vector Regression algorithm on the features selected by Elastic Net has the least cross-validation mean squared error.

Optical evaluation of the shading properties of climbing fern Lygodium japonicum used as thermal buffering green wall plant

Recently, thermal properties of the landscaped rooftops and walls have attracted the interest of researchers because of the potential to minimize energy consumption in urban areas and to aid summer-time thermal control. For this reason the creation of a plant-based shade for walls or above buildings is highly important. In this paper we evaluate using Lygodium japonicum, one of the many ferns and fern allies traditionally used in Japanese gardening, as a component of thermal-buffering green walls. Lygodium japonicum, the only climbing fern species in Japan, is fast-growing, adheres easily to walls and has a climbing nature. A simple thermal analysis of the sun-shading effect of Lygodium canopy suggested that local surface temperature above the ceramic tiles placed on the rooftop of a building can be buffered (lowered in daytime and maintained relatively warm at night) by the presence of leafy climbing ferns covering the tiles, possibly due to the reflection and absorbance of solar radiation. Furthermore, the presence of the plants may also slow the night-time release of heat from the building surface. Because plants installed on tall walls or on the tops of buildings are not easily accessed for manual care, we performed a real-time routine monitoring and control of plant growth status using various optical sensors that could be automated and monitored remotely for large-scale applications. For this purpose, the optical properties of a Lygodium canopy under solar incident light have been determined. In order to evaluate the natural shading and growing properties of a green canopy, the incident solar radiation spectrum (J), leaf canopy-filtered light spectrum (transmittance, T) and leaf-reflectivity spectrum ® were measured. By reading the reflectivity spectrum, concomitant chlorophyll fluorescence signals (F) from Lygodium leaves were also detected at 760 nm, which corresponds to the O2-A Fraunhofer line. Our data suggests that the daily change in photosynthetic status (P) can be traced by monitoring the change in relative F in relation to the estimated heat loss (H) and measured J, R, and T using a series of practical equations designed to roughly estimate the gross photosynthetic response within the plant canopy. Using our equations, the photosynthetic capacity in the plant canopy structure could be simply simulated and predictable by optical sensors.

Numerical Evaluation of the Local Weather Data Impacts on Cooling Energy Use of Buildings in an Urban Area

Accurate weather data plays an important role in the evaluation of building energy consumption in urban areas. The local air temperature and local wind speed can vary significantly due to the influence of microclimate conditions, while those parameters have a significant effect on energy demand especially in the summer. This study provides a new coupled numerical approach that building energy simulation (BES), using the airport weather data, transfers building surface temperature data to computational fluid dynamics (CFD) as the boundary conditions. In addition, the outdoor thermal environment is simulated using the CFD method and local weather data is calibrated and transferred to BES as the real-time meteorological data. A daily coupled simulation is performed for a building located in a specified urban density accounting for actual wind speed and direction. The comparison shows that the difference for daily building energy consumption is up to 2.5% using the airport weather data and local weather data. Therefore, accurate estimation of local weather data is necessary when on-site measured data is not available.

The Factors Influencing Transport Energy Consumption in Urban Areas: a Review

Transport energy consumption accounts for about one third of total energy consumption in EU. Despite significant advances in transport technology and fuel formulation, transport energy consumption has increased in most EU countries over the last three decades. This increase in consumption occurred as a result of factors such as higher car ownership, a growth in automobile use and an increase in vehicle distances traveled. As travel and land-use are a function of one another, it is often hypothesized that changing urban structure can result in changes in energy consumption. Understanding how different land use characteristics may influence travel behaviour and the corresponding energy consumption is crucial for planners and policy makers in order to develop strategic actions to shrink the environmental footprint of the urban transportation sector. The aim of this article is to review the current literature on the connections between land use, travel behavior and energy consumption. In particular, this paper seeks to identify the determinants of transport energy consumption in urban areas by reviewing evidence from empirical studies. To this aim, nine characteristics of land use are presented and their effects on both travel behaviour and energy use are discussed Our review shown that, in contrast to the focus on the effect of the built environment on travel, only few researchers have empirically investigated the linkage between the built environment and transportation energy use. The research described in this paper has been developed within the PON 04a2_E Smart Energy Master project. It represents part of a much broader research project aimed at the development of an integrated model of urban energy efficiency.

Cold and warm air temperature spells during the winter and summer seasons and their impact on energy consumption in urban areas

The main objective of this study is to determine and analyze cold and warm air temperature spells in the last 6 years (2007–2012) and reveal their impact on electrical energy consumption in a small-sized city such as Sombor (Serbia) with less than 50,000 inhabitants. Hourly air temperature values and electrical energy consumption data have been used as database for all methods. Warm and cold temperature spells (during heat and cold waves) have had the increasing tendencies in the last 6 years and they reflect on additional electrical energy consumption. Detailed analysis showed that higher energy demands occur during workdays and daytime period. Monitoring of the amount of consumed energy showed a clear relationship during the winter cold temperature spells, when electrical energy demand was higher than 0.3 MW. In summer period, the relationship was weaker and consumption was higher than 0.15 MW only when temperature exceeded 30 °C. A small number of air condition devices in houses and companies and mainly one-store buildings with thick walls, which make a good insulation from the outside air temperatures, are probably the main reasons for the above-mentioned results in summer. This paper introduces a new method to resolve the problem of short-term load forecasting, based on the support vector machines (SVM) technology and particle swarm optimization that has been used to optimize the SVM parameters. Similar-day-based forecast has shown that similar days for training should be filtered also using classifier of temperature period (cooling degree-days or heating degree-days in a row). Forecasting error is smaller compared to solutions where similar days are found only on season and temperature.

A feasibility evaluation tool for sustainable cities – A case study for Greece

Designing measures for the reduction of energy consumption in urban areas is a complex venture indeed. In terms of urban sustainability, such measures affect energy efficiency as well as environmental, economic and social aspects. Numerous publications dealt with such methodological approaches in the past, whilst the subject of sustainable urban areas and cities is constantly gaining interest. Furthermore, energy performance depends on building density, occupancy and consumer profile, climatic conditions, not least construction quality, factors linked, directly or not, to socioeconomic aspects. Greek cities are known for their density, their polymorphic structure and their complexity. Thus, planning energy conservation measures is a difficult task, demanding a precise methodological approach, which will embody most of these aspects to a great extent. This paper proposes a methodology on how to manage Greek cities in terms of their energy efficiency, emphasizing on the residential stock.

A Study on Energy Saving and Light Pollution of LED Advertising Signs

Lighting advertising signs not only play an important role in outdoor lighting environment in Taiwan, but also become the main factor of energy consumption in urban areas at night. Light-emitting diode (LED) has been gradually used in advertising signs due to its advantages. However, in order to be conspicuous and legible in the daytime, signs that are excessively bright may result in considerable light pollution and energy waste at nighttime. Therefore, this research aims to measure the luminance of LED signs and traditional internally lighted signs, and analyze the light trespass from each signage. Based on the research results, the energy consumption from a LED full color screen is 12 times more than a traditional internally lighted sign per day. Statistically, all kinds of LED signs are much higher than traditional internally lighted signs in the percentage of excessive brightness and average luminance value. As for the light trespass, since the vertical illuminance on facade facing the signs increases with the increase of the sign area or the decrease of the distance between the sign and the facade, the vertical illuminance on facade facing the signs would exceed the limit of CIE even if the luminance of the signs achieves the standard of CIE in terms of the general conditions in Taiwan. This happens to LED full color screens in particular and thus results in considerable obtrusive light. To sum up, in order to reduce unnecessary energy consumption and improve the nighttime lighting quality for outdoor environment, this research recommends the luminance limitation for light dimming of LED advertising signs should refer to the zoning, time period, and sign area.

International Comparison of Energy Consumption in Urban Area

International Comparison of Energy Consumption in Urban Area

Modeling energy consumption and CO 2 emissions at the urban scale: Methodological challenges and insights from the United States

Local policy makers could benefit from a national, high-resolution inventory of energy consumption and related carbon dioxide (CO 2) emissions based on the Vulcan data product, which plots emissions on a 100 km 2 grid. We evaluate the ability of Vulcan to measure energy consumption in urban areas, a scale of analysis required to support goals established as part of local energy, climate or sustainability initiatives. We highlight the methodological challenges of this type of analytical exercise and review alternative approaches. We find that between 37% and 86% of direct fuel consumption in buildings and industry and between 37% and 77% of on-road gasoline and diesel consumption occurs in urban areas, depending on how these areas are defined. We suggest that a county-based definition of urban is preferable to other common definitions since counties are the smallest political unit for which energy data are collected. Urban counties, account for 37% of direct energy consumption, or 50% if mixed urban counties are included. A county-based definition can also improve estimates of per-capita consumption.

On Cold Materials of Pavement and High-Temperature Performance of Asphalt Concrete

With global climate becoming warmer more and more attention is being paid to cold materials. Lower surface temperature contributes to decrease the temperature of the ambient air as heat convection intensity from a cooler surface is lower. Such temperature reductions can have significant impacts on cooling energy consumption in urban areas, a fact of particular importance in hot climate cities. The black surface of asphalt pavement absorbs more heat from the sun, and higher temperature of pavement surface contributes to increase the effect of the urban heat island, but affects the performance and life span of a pavement. Asphalt pavements form an integral part of any transportation system and are typically engineered to last 15 years or more, but many have been failing early due to potholes, cracks, raveling and other problems. Cool pavement are mainly aimed to decrease the effect of asphalt pavement on the urban heat island, but the influence of cold materials on the high-temperature performance of asphalt concrete pavement is paid little attention relatively. In this paper, it’s discussed that the effect of asphalt-pavement high temperature and its improving measures. And the mechanism of cool pavements is introduced, and possible technologies applied to asphalt pavements are reviewed. The idea of asphalt concrete pavement with automatic temperature-control is put forward.

Spatial Development and Energy Consumption

Some literature suggests that population density, size of a city, and how the population is distributed - together known as urban form - have an impact on energy consumption in urban areas. This paper explores two ideas: (1) whether or not energy efficiency improvement would result from compacting a previously disbursed city, and (2) what land use policies would reduce energy consumption in urban areas.