Development of a dynamic incentive and penalty program for improving the energy performance of existing buildings

The positive effectiveness of energy policy instruments such as national carbon emissions reduction target (CERT) and energy performance certificates can be achieved by encouraging the voluntary participation of the public in the energy-saving campaign. Towards this end, this study aimed to develop a dynamic incentive and penalty program for improving the energy performance of existing buildings. Four types of incentive programs and four types of penalty programs were established based on three comparison criteria. As a building-level, the first comparison criterion is the averaging approach based on similar cases that can be retrieved using a simplified case-based reasoning model. As a community-level, the second comparison criterion is one-step higher operational and letter rating than the grade of a given building. As a national-level, the third comparison criterion is the operational and letter rating as the minimum criteria for achieving the national CERT. In this study, an elementary school facility located in Seoul, South Korea was selected to validate the applicability of the developed program. As a result, besides the category benchmark, the various comparison criteria should be provided to the public to encourage the voluntary participation of the public in the energy-saving campaign. First published online: 19 Feb 201

Estimation of the Available Rooftop Area for Installing the Rooftop Solar Photovoltaic (PV) System by Analyzing the Building Shadow Using Hillshade Analysis

AbstractFor continuous promotion of the solar PV system in buildings, it is crucial to analyze the rooftop solar PV potential. However, the rooftop solar PV potential in urban areas highly varies depending on the available rooftop area due to the building shadow. In order to estimate the available rooftop area accurately by considering the building shadow, this study proposed an estimation method of the available rooftop area for installing the rooftop solar PV system by analyzing the building shadow using Hillshade Analysis. A case study of Gangnam district in Seoul, South Korea was shown by applying the proposed estimation method

An integrated multi-objective optimization model for solving the construction time-cost trade-off problem

As construction projects become larger and more diversified, various factors such as time, cost, quality, environment, and safety that need to be considered make it very difficult to make the final decision. This study was conducted to develop an integrated Multi-Objective Optimization (iMOO) model that provides the optimal solution set based on the concept of the Pareto front, through the following six steps: (1) problem statement; (2) definition of the optimization objectives; (3) establishment of the data structure; (4) standardization of the optimization objectives; (5) definition of the fitness function; and (6) introduction of the genetic algorithm. To evaluate the robustness and reliability of the proposed iMOO model, a case study on the construction time-cost trade-off problem was analyzed in terms of effectiveness and efficiency. The results of this study can be used: (1) to assess more than two optimization objectives, such as the initial investment cost, operation and maintenance cost, and CO2 emission trading cost; (2) to take advantage of the weights as the real meanings; (3) to evaluate the four types of fitness functions; and (4) to expand into other areas such as the indoor air quality, materials, and energy use

Development of the monthly average daily solar radiation map using A-CBR, FEM, and kriging method

Photovoltaic (PV) system could be implemented to mitigate global warming and lack of energy. To maximize its effectiveness, the monthly average daily solar radiation (MADSR) should be accurately estimated, and then an accurate MADSR map could be developed for final decision-makers. However, there is a limitation in improving the accuracy of the MADSR map due to the lack of weather stations. This is because it is too expensive to measure the actual MADSR data using the remote sensors in all the sites where the PV system would be installed. Thus, this study aimed to develop the MADSR map with improved estimation accuracy using the advanced case-based reasoning (A-CBR), finite element method (FEM), and kriging method. This study was conducted in four steps: (i) data collection; (ii) estimation of the MADSR data in the 54 unmeasured locations using the A-CBR model; (iii) estimation of the MADSR data in the 89 unmeasured locations using the FEM model; and (iv) development of the MADSR map using the kriging method. Compared to the previous MADSR map, the proposed MADSR map was determined to be improved in terms of its estimation accuracy and classification level. First published online: 03 May 201

Framework for the validation of simulation-based productivity analysis: focused on curtain wall construction process

 As construction projects have become more complicated in design and construction, it is necessary to establish the construction operational plans in advance. However, there were some limitations in analyzing construction produc­tivity due to the difficulty of collecting accurate data. To address this challenge, this study aimed to develop the frame­work for the validation of simulation-based productivity analysis, which consisted of three measures: (i) validation of the measured productivity data as target variable; (ii) validation of the measured duration data as input variable; and (iii) validation of the simulation model compared to the actual construction process. To verify the feasibility of the proposed framework, this study focused on the curtain wall construction project of “S” office building as a case study. The T-test was applied to investigate the statistical difference between the measure and simulated productivity. It was determined that the significance level α in the T-test for the unloading process was 0.136 with 95% confidence interval; the lifting process, 0.106; and the installing process, 0.311. As a result, there was no significant difference between the measured and simulated productivity. The proposed framework could enable executives and managers in charge of project plan­ning and scheduling to accurately predict the simulation-based productivity. First published online: 13 Jul 201

Development of the life-cycle economic and environmental assessment model for establishing the optimal implementation strategy of the rooftop photovoltaic system

To maximize the life-cycle economic and environmental performance of the rooftop pho­tovoltaic (PV) system in real projects, it is necessary to consider several factors such as regional climate factors (i.e., geographical and meteorological factors) and building characteristics (i.e., on-site installation factors, rooftop area limit, and budget limit). Towards this end, this study aimed to develop the life-cycle economic and environmental assessment model for establishing the optimal implementation strategy of the rooftop PV system. The robustness and reliability of the developed model were evaluated in terms of two perspectives: (i) for the effectiveness of the optimal solution, the optimization results were generated by considering the regional climate factors and building characteristics. Namely, the results for SIR25 (saving to investment ratio at year 25), which was set at the optimization goal, were 2.540 (Busan, southern part of South Korea), 2.485 (Daejeon, central part of South Korea), and 2.266 (Seoul, northern part of South Korea), respectively; and (ii) for the efficient computation time, the time required for determining the optimal solution was only 27 seconds. The developed model can be used to easily and accurately assess the life-cycle economic and environmental performance of the rooftop PV system in the early design phase. First published online 14 April 2016&nbsp

A Techno-Economic Feasibility Analysis of Mono-Si and Poly-Si Photovoltaic Systems in the Rooftop Area of Commercial Building under the Feed-In Tariff Scheme

Hong Kong’s government has recently introduced the feed-in tariff scheme to promote the photovoltaic (PV) system as a promising way to address global warming. The feed-in tariff scheme depends on the type of the PV system and its installed capacity. This study aimed to investigate the techno-economic feasibility of mono-Si and poly-Si PV systems in the rooftop area of a commercial building, Pao Yue-Kong Library of Hong Kong, under the feed-in tariff scheme. The analysis was carried out in two phases: (i) technical analysis of the rooftop PV systems by considering the shading effect and solar radiation and (ii) economic feasibility of the rooftop PV systems under the feed-in tariff scheme from the life cycle perspective. The main findings of the case study can be summarized: (i) the rooftop area of the target building would not be significantly affected by surrounding buildings; (ii) the highest amount of solar radiation was estimated at 136.96 kWh/m2 in October, while the lowest value was 55.64 kWh/m2 in February; (iii) the total amount of module energy yield from the mono-Si PV system was estimated at 917.58 kWh/kW, indicating that it was very similar but a little bit lower (i.e., 0.48%) than that for the poly-Si PV system (i.e., 921.98 kWh/kW); and (iv) payback periods for mono-Si and poly-Si PV systems were estimated at 8.67 and 8.31 years, respectively. The feasibility study can contribute to providing facility managers with a practical guideline to determine the appropriate strategy in implementing the PV systems in buildings under the feed-in tariff scheme

A break-even analysis and impact analysis of residential solar photovoltaic systems considering state solar incentives

Despite the steady growth and price reductions of solar photovoltaic (PV) market in the United States (U.S.), the solar PV market still depends on financial support and incentives due to its high initial investment cost. Therefore, this study aimed to conduct a break-even analysis and impact analysis of residential solar PV systems by state in the U.S., focused on state solar incentives. Three indexes (i.e., net present value, profitability index (PI) and payback period) were used to evaluate the investment value of the residential solar PV systems considering state solar incentives. Furthermore, PI increase ratio was used to analyze the impact of state solar incentives on the economic feasibility of the residential solar PV systems in each state. As a result, it was found that 18 of the 51 target cities have reached the break-even point and seven of the 51 target cities showed great improvement of the economic feasibility of solar PV systems in the U.S. due to excellent state solar incentives. The results of this study can help policy makers to evaluate and compare the economic impacts of the residential solar PV systems by state in the U.S. First published online: 09 Feb 201