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Energy economy restructuring at the city level is an essential prong in any strategy that aims to address the dual energy and climate change challenges. Cities form hubs of human activity that are accompanied by high levels of energy consumption and emissions but also contain existing resources and infrastructure to transition to a greener energy economy. This paper reviews efforts to date to define the ‘solar city’ concept and assessment methods for estimating the solar electric potential of an often neglected but vital city resource in energy matters – its rooftop real estate. From this review, an application of the solar city concept is formulated and an assessment method is offered for its investigation. An illustrative case study is provided, using the City of Seoul, South Korea. Representing nearly one-quarter of South Korea’s population and a one-third of its economic activity, the application of the solar city concept to the city can have significant consequences for the future energy development pathway of the municipality and the country (the metropolitan area of Seoul encompasses nearly one-half of the national population). The research demonstrates that a technical potential equivalent to almost 30% of the city’s annual electricity consumption can be supplied by widespread deployment of rooftop-based distributed photovoltaic systems. Using the methodology developed in the paper, we estimate that sixty-six percent of the annual daylight-hours electricity needs of the City of Seoul can be served by distributed solar power systems on a typical day. It is additionally found that considerable peak shaving is possible, lessening the pressure on the city’s electricity grid. These findings can be expected to extend to other large cities when the solar city concept is thoughtfully applied. [ABSTRACT FROM AUTHOR]

Energy is considered the most costly and scarce resource, and demand for it is increasing daily. Globally, a significant amount of energy is consumed in residential buildings, i.e., 30–40% of total energy consumption. An active energy prediction system is highly desirable for efficient energy production and utilization. In this paper, we have proposed a methodology to predict short-term energy consumption in a residential building. The proposed methodology consisted of four different layers, namely data acquisition, preprocessing, prediction, and performance evaluation. For experimental analysis, real data collected from 4 multi-storied buildings situated in Seoul, South Korea, has been used. The collected data is provided as input to the data acquisition layer. In the pre-processing layer afterwards, several data cleaning and preprocessing schemes are applied to the input data for the removal of abnormalities. Preprocessing further consisted of two processes, namely the computation of statistical moments (mean, variance, skewness, and kurtosis) and data normalization. In the prediction layer, the feed forward back propagation neural network has been used on normalized data and data with statistical moments. In the performance evaluation layer, the mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean squared error (RMSE) have been used to measure the performance of the proposed approach. The average values for data with statistical moments of MAE, MAPE, and RMSE are 4.3266, 11.9617, and 5.4625 respectively. These values of the statistical measures for data with statistical moments are less as compared to simple data and normalized data which indicates that the performance of the feed forward back propagation neural network (FFBPNN) on data with statistical moments is better when compared to simple data and normalized data. [ABSTRACT FROM AUTHOR]

Highlights • The paper studies the impact of urban parks on reducing urban temperature. • Findings reveal that urban park construction reduces building energy consumption. • There is a limit distance to the reduction of energy consumption due to urban parks. • Change of urban characteristics due to park construction affects energy consumption. Abstract A change in the thermal environment of an urban area affects health, living conditions, and energy consumption. In urban planning, urban parks are one of the methods for improving the thermal environment and saving cooling energy. Urban park construction can mitigate temperature, but it also causes urban development by increasing local attractiveness. To achieve efficient energy saving through parks in urban planning, the purpose of this study is to investigate the relationship between building energy consumption and urban characteristics both before and after the construction of an urban park. This study targeted Seoul's Gyeongui line forest, which was recently converted into a linear park on the former railway as an urban regeneration project. We analyzed the relationship between energy consumption and urban characteristics using a regression model, focusing on the changes before and after the construction. In this study, urban characteristics include environment, building physical characteristics, and economic variables. The results show that the construction of the urban park reduced not only temperature but also building energy consumption. The energy reduction effect of the park was limited to a marginal distance. Meanwhile, the urban park construction caused land prices to rise and prompted new development, and this changed the urban characteristics of the area and affected energy consumption. Despite changes in urban characteristics, urban park planning is an effective methods of reducing the energy consumption involved in cooling urban areas. We recommend comprehensive consideration of the urban factors when making park policy to reduce urban temperature and energy consumption. [ABSTRACT FROM AUTHOR]

• This paper determines the relationship between urban form and building energy use. • The surface-to-volume ratio and obstruction angle of buildings are important. • Consideration of the heating energy type and building use can yield reliable result. • The urban heat island effect exerts an impact on the electricity use in some months. • Correlation variation is caused by the building permit date. In the climate change era, urban geometry serves to ensure sustainability for urban planners since it notably affects building energy consumption. However, previous studies have mainly conducted experimental investigations under hypothetical conditions. Without empirical evidence, it is difficult to implement these findings under real conditions. This paper examined empirical data to determine the urban geometry effect on building energy consumption in a large, complicated urban area. Urban geometric parameters, including the surface-to-volume ratio, obstruction angle, and building orientation, were measured across Seoul, and their correlations with building energy use were analyzed. The results show that the surface-to-volume ratio and obstruction angle are important, despite the empirical data complexity. Additional data analysis indicates that the heating energy type and building use consideration yields more reliable correlation coefficient trends. The potential impacts of natural ventilation and the urban heat island (UHI) effect on building energy consumption were examined. The UHI effect, rather than shadows on buildings, predominantly impacts the building electricity use in August and September. The correlation variation caused by the building permit date was investigated. The results in this paper could help urban planners and designers develop blueprints to control urban geometry and establish relevant design guidelines. [ABSTRACT FROM AUTHOR]

Personal Mobility (PM) has attracted considerable attentions as an eco-friendly mode of transportation. In Seoul, the PM penetration rate has grown by 30% annually, and the number of PM companies has been increasing. However, there is a high risk of collision against a pedestrian while riding PM vehicles on sidewalks. To create a safer operation environment, studies on the effect of PM-only lane and ways to create PM playgrounds have been conducted. A design involving a PM-only lane was presented and evaluated using the traditional travel demand modeling framework. If the PM-only lane is to be implemented, a significant number of vehicles would be converted for public transportation, and vehicle kilometers traveled would be substantially decreased. Reducing the use of automobiles is expected to contribute to environmental benefits. Moreover, by creating a PM-based playground, it can promote a safer driving environment through driving education for beginners, and data collection related to PM driving. If PM-only lane and PM-based playgrounds positively affect the deployment of PM, they could lead to the activation of public transportation uses. Environmental benefits calculated on these action plans show its effectiveness of reduction of mobility energy consumption while ensuring safety and convenience. • Action plans in the paper could lead to activate Personal Mobility (PM) use. • These could increase environmental benefits while to decrease traffic accidents. • The designs of the action plans are how to implement PM only lanes and playground. [ABSTRACT FROM AUTHOR]

This paper proposes a model to calculate the magnitude of the reduction in household electricity use that results from a progressive pricing policy, relative to the case where uniform pricing is implemented. To quantify such an effect, a theoretical model is developed for household electricity use, and then it is applied to the progressive pricing policy for electricity in Seoul, South Korea, to empirically derive the magnitude of the reduction in household electricity use. The results suggest that progressive pricing reduces the elasticity in demand for household electricity in the summer. That is, the progressive pricing policy has a curbing effect. Therefore, households would consume a higher amount of electricity in the summer without progressive pricing. [ABSTRACT FROM AUTHOR]

The recent increase in energy consumption worldwide has accelerated global warming. Thus, developed countries are aiming to reduce energy consumption in cities and promote eco-friendly policies. Buildings account for most of the energy used in a city. Therefore, it is necessary to identify the factors that affect electrical energy consumption in urban buildings. In this study, we use multiscale geographically weighted regression (MGWR) to analyze these urban characteristic factors at the global and local scales in Seoul, Korea. It is found that population and household characteristics, outdoor temperature, green and water areas, building area according to building usage, and construction age significantly affect the electrical energy consumption of buildings. In addition, the influences of these variables change with the region. Variables with different coefficients by region are winter temperature, green and water area, and households with three or more persons. The results confirm that even within a city, the influence of the aforementioned factors varies in terms of spatial distribution and patterns. This study is significant as it carried out basic research for energy consumption reduction in buildings by deriving related influencing factors. [ABSTRACT FROM AUTHOR]

South Korea is pursuing an energy transition policy (ETP) of expanding the use of renewable energy and natural gas and decreasing that of nuclear energy and coal in total generation. An investigation of whether the public is for or against the ETP is needed by the government. This article explores the public preference toward the ETP employing the data collected through a survey of 1000 individuals. They were asked to reveal their preference for the ETP on a five-point scale in the survey. Overall, there are more advocates of the ETP than those who opposed it. For the purpose of analyzing the determinants of advocacy and opposition of the ETP, an ordered probit model is employed. The results suggest that people living in the Seoul Metropolitan area think that the environment is more important than new jobs, or know the renewable energy 100% campaign before the survey is more favorable to the ETP than others. However, people who use electricity for heating tend to be negative about the ETP. As the age increases, people approve of the ETP, but when age goes beyond a certain level, they oppose it. [ABSTRACT FROM AUTHOR]

The South Korean government is presently conducting a research project to provide measurement-based building energy consumption data for individual end uses, such as space heating, space cooling, domestic hot water (DHW), and other uses. From 2014 to 2019, energy consumption measurement systems for each end use were installed in sample buildings, and the measured data are being statistically processed with the objective of constructing an information system for energy use and CO 2 emission intensities by end use. This paper presents the statistical data for the site and primary energy use intensities (EUIs) and the CO 2 emission intensities by end use for the period of May 2017–April 2018; the data were obtained from measurements in 71 sample apartment units located in Seoul. The average site EUIs display the following order: space heating > electrical appliances > DHW > cooking > lighting > space cooling > air movement. Electrical appliances have the largest average primary EUI and CO 2 emission intensity. The average site EUIs exhibit the same order as those of the US Residential Energy Consumption Survey 2015 data: space heating > electrical appliances, etc. > DHW > space cooling. [ABSTRACT FROM AUTHOR]

This article aims to examine how a metropolis like Seoul could be resilient to imminent environmental crisis in the era of climate change. To do so, it conducts a case review of the 'One Less Nuclear Power Plant' (OLNPP) policy adopted under the progressive leadership of Mayor Park Won-soon (2011–). The policy was launched in April 2012, with a target of cutting energy use by 2 million tons of oil equivalent (TOE), which is equivalent to the capacity of one nuclear power plant. The target was accomplished in June 2014, six months ahead of schedule. The second phase of OLNPP has been in progress since August 2014 (and is due to complete in 2020). Focusing on its first phase (2012–2014), the article looks into the OLNPP as an experiment for the city's transition to a resilient energy regime. Following the Introduction, the article reviews the conceptual relationships between risk, resilience and governance in an urban context. This is followed by examination of the background of the OLNPP policy, which was adopted by a progressive leader, and of how the OLNPP as an energy transition project is formulated as geared to enhancing resilience in the city's energy regime. The next section addresses the progressive mode of governing the implementation of the OLNPP, which leads to resilient energy life, giving rise to a progressive form of city. The conclusion characterises the relationship between the progressivity and resiliency of a new energy system by locating it in a framework of conceptualising a progressive city, while outlining the future of the OLNPP. [ABSTRACT FROM AUTHOR]

The application of phase change materials (PCMs) in building envelopes can help promote energy efficiency due to its high heat capacity. Our study aimed to provide energy and economic insights for deploying PCM to buildings in eight different regions of East Asia through a series of energy and economic analysis using computer modelling and simulations. The static payback period (SPP) and dynamic payback (DPP) methods were used to evaluate the economic feasibility of applying a PCM at different melting phase temperatures (20°C, 23°C, 25°C, 27°C and 29°C). Results show that the proper choice of a PCM melting temperature is a key factor to improve the performance of the PCM applied to buildings. A melting phase temperature of 29°C achieved the highest economic feasibility in Seoul, Tokyo; Pyongyang; Beijing; and Ulaanbaatar and a melting temperature of 23°C in Hong Kong had the highest economic feasibility. Overall, the combined economic and energy analysis presented in this study can play an important role in improving the energy and economic feasibility of PCM in buildings. [ABSTRACT FROM AUTHOR]

Growths in population, increasing demand for health care services and comfort levels, together with patients on the rise in time spent inside hospitals, assure the upward trend that energy demand will continue in the future. Since the hospital buildings operate 24 hours, 365 days a year for the treatment and restoration of patients, they are approximately 2–3 times more energy-intensive than normal buildings. For this reason, energy efficiency in hospitals is one of the prime objectives for energy policy at regional, national and international levels. This study aims to find how meaningful energy performance, reflecting good energy management and energy conservation measures (ECMs), can be operated for hospital buildings, a category encompassing complex buildings with different systems and large gaps between them. Energy audit allows us to obtain knowledge from the healthcare facility, in order to define and tune data driven analysis rules. The use of benchmarking in the energy audit of healthcare facilities enables immediate comparison between hospitals. Data driven energy analysis also allows ascertaining their expected energy consumption and estimating the possible savings margin by using the building energy flow chart. In the 2015–2017 periods, bench-marking of four public hospitals in Seoul were audited for the energy consumption related to weather conditions, total area, bed numbers, employee numbers, and analyzed for building energy flow by zones, energy sources, systems and equipment. This is a practice-based learning in a hospital project. The results reveal that the average annual energy consumption of a hospital under normal conditions, and energy efficiency factors are divided into energy baselines, energy consumption goals for energy saving and energy usage trends for setting ECMs, respectively. The indicator dependent on the area of inpatients (number of beds) proved to be the most suitable as a reference to quantify the energy consumption of a hospital. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a mathematical regression model for predicting end-use energy consumption in the residential sector. To this end, housing characteristics were collected through a field survey and in-depth interviews with residents of 71 households (15 apartment complexes) in Seoul, South Korea, and annual data on end-use energy consumption were collected from measurement systems installed within each apartment unit. Based on the data collected, correlativity between the field-survey data and end-use energy consumption was analyzed, and effective independent variables from the field-survey data were selected. Regression models were developed and validated for estimating six end uses of energy consumption: heating, cooling, domestic hot water (DHW), lighting, electric appliances, and cooking. Regression analysis for ventilation was not applied, and instead a calculation formula was derived, because the energy-consumption proportion was too low. The adj-R2 of the estimation model ranged from 0.406 to 0.703, and the maximum error between measured and estimated values was around ±30%, depending on the end use. [ABSTRACT FROM AUTHOR]