The Role of Green Sukuk for Sustainable Energy Production

Renewable energy sources are clean energy sources that meet the energy needs in a sustainable way. Therefore, it is necessary to invest in renewable energy sources. However, there are some difficulties in renewable energy investments. It has problems such as high initial installation cost, underdeveloped technological infrastructure, and insufficient financial support. Several financial products are being developed in order to overcome the mentioned difficulties. In this context, the purpose of this study is to explain the role of green sukuk in the financing of renewable energy investments. Depending on this purpose, the study has been examined with a literature review. The production of renewable energy sources can be encouraged with green sukuk. However, green sukuk is an advantage for Islamic companies that want to realize environmental projects. On the other hand, it offers the opportunity to the environmentally friendly Islamic investors to evaluate their savings.

STATE OF THE ART OF SMALL WIND ENERGY ANALYSING DIFFERENT CONTROLS

There are two wind turbine topologies according to the axis of rotation: horizontal axis, "Horizontal Axis Wind Turbines" (HAWT) and vertical axis, "Vertical Axis Wind Turbines" (VAWT) [2]. HAWT turbines are used for high power generation as they have a higher energy conversion efficiency [2]. However, VAWTs are used in mini wind applications because they do not need to be oriented to the prevailing wind and have lower installation cost.

The Analysis of Residential Rooftop PV in Indonesia’s Electricity Market

This study aimed to examine the customer interest in using rooftop PV considering the economic background and customer profile in Indonesia’s electricity market using primary survey data with potential and existing (households and industries) respondents. This research uses logit model regression to analyze the impact of the demographic background of respondents and uses exploratory factor analysis (EFA) to understand the reasons why the existing users utilize rooftop PV at their homes. The results show that education, residence location, and income can positively and significantly affect the probability of using rooftop PV as the source of electricity. Then, there are several factors that influence the use of rooftop PV, such as easily finding it in their area, having concern for the environment, following trends, and loyalty. Some disadvantages of installing rooftop PV are felt by users, such as relatively high installation cost and frequent overheating during usage. Regarding customer satisfaction, most of the respondents from both households and industries answered that they were satisfied with their rooftop’s PV. Consumers say that the benefits they obtain are comparable to the required installation costs, and the majority of consumers also said that the rooftop PV worked well and did not need many repairs every month, so consumers did not need to spend significant money on it.

Perforated Steel Stud to Improve the Acoustic Insulation of Drywall Partitions

Steel studs are an inevitable part of drywall construction as they are lightweight and offer the required structural stability. However, the studs act as sound bridges between the plasterboards, reducing the overall sound insulation of the wall. Overcoming this often calls for wider cavity walls and complex stud decoupling fixtures that increase the installation cost while reducing the floor area. As an alternative approach, this research reveals the potential of perforated studs to improve the acoustic insulation of drywall partitions. The acoustic and structural performance is characterized using a validated finite element model that acted as a prediction tool in reducing the number of physical tests required. The results established that an acoustic numerical model featuring fluid-structure-interaction can predict the weighted sound reduction index of a stud wall assembly at an accuracy of ±1 dB. The model was used to analyze six perforated stud designs and found them to outperform the sound insulation of non-perforated drywall partitions by reducing the sound bridging. Overall, the best performing perforated stud design was found to offer improvements in acoustic insulation of up to 4 dB, while being structurally compliant.

Kriteria Prioritas Pemilihan Teknologi Pengolahan Limbah Cair Industri Tempe

The location of tempe processing adjacent to the settlement causes problems. The resulting liquid waste makes people uncomfortable. This is presumably because the liquid waste has not been managed properly, because it is only dumped into the drainage channel. The majority of tempe industrial entrepreneurs are home industries who are not aware of creating a healthy environment by paying attention to liquid waste processing. There are many studies on technology for the tempe industrial wastewater problem, but each technology has advantages and disadvantages. It is necessary to have a system to choose the technology that suits the waste conditions. This research takes a case study in Karanganyar Regency. The Analytical Hierarchy Process (AHP) method is a method of determining priority scale that can accommodate all aspects. Furthermore, a sequence of criteria can be arranged as needed. The results of the analysis with AHP are: technology criteria 31.09%; environment 28.65%; economic 21.74% and social 18.53%. Environmental sub-criteria showed the results of the removal of ammonia 40.56%; treated water quality 30.74%; the amount of mud is 18.91% and the emission level is 9.80%. Technology sub-criteria are ease of operation 28.67%; land area requirement 28.56%; service life of 28.05% and the potential of technology in the midification of 14.72%. Economic sub-criteria with the results of operating costs 34.21%; installation cost 33.28%; maintenance costs 23.78% and HR costs 8.73%. Social sub-criteria with the results of the need for employment of 49.10%; readiness of human resources 19.33%; implementation of construction 16.74% and aesthetics 14.82%. The results of the AHP can be used as input for tempe entrepreneurs, the government and the community to improve the environmental quality of the tempe industrial wastewater. It is hoped that entrepreneurs will find it easier to determine the appropriate technology to treat the tempe industrial liquid waste.

Five-Year Performance of an ESE Lightning Protection System for a Large Scale PV Power Plant in Thailand

This article presents a five-year performance review of an early streamer emission (ESE) air terminal lightning protection system for a large scale PV power plant in Thailand. The comparison effect of a Franklin lightning protection system and the ESE lightning protection system was analyzed for the PV power plant. The ESE lightning protection system was selected to be implemented in the PV power plant. The capacity of the PV power plant studied was 8 MWp on an area of 150,000 square meters in the Nong Ya Plong district, Phetchaburi province, Western Thailand. A Franklin lightning rod type was also designed to be implemented in this PV power plant. The Franklin lightning rod type comprised 122 pieces but the ESE lightning rod type consisted of only 11 pieces. The conceptual design of the Franklin rod type followed the standard of the Council of Engineers, Thailand, and the ESE lightning rod type followed the NFC17102 standard of France. The estimated cost of installation was a key comparison to select the lightning protection system; the total installation cost of the Franklin lightning rod type was USD 197,363.80 and the ESE lightning rod type was USD 44,338.06. The lightning system was applied to the lightning arrester in the power plant to provide good protection, in which the balance of the pole to the mounting position is required to optimize the system performance. The result of the simulation also showed that the shading effects of the Franklin rod type were greater than the ESE rod type. The installation cost of the Franklin lightning rod type was 4.45 times more expensive than the ESE lightning rod type. Therefore, the ESE lightning protection system was selected to be implemented in the PV power plant. From the recorded data of the five-year performance of the ESE lightning protection system (2016–2020), there were three occurrences of a lightning strike on the PV power plant. The ESE lightning protection system effectively protected and prevented the lightning strike to the PV power plant. This study can help and support with the selection of a lightning system for the protection of large scale PV power plants in the future.

Implementation Analysis of Solar PV Based SEPIC Inverter System

For welfare of environment, world needs to use more and more renewable energy system not only at the level of industrial but also for domestic load system. Due to much installation cost involving in a solar PV cell/panel based system there is a need of better mechanisms to get maximum utilization and benefits from the system with reliable operation, especially in the case of microgeneration power plant to full fill the minimum desired requirements of domestic appliances to achieved reliable operation. Mostly available PV based inverter system having problem of low output voltage generation and THD producing issue, which needs to a requirements of extra circuit to the control THD and boost up the level of output voltage. In this paper, solar PV based closed loop SEPIC converter by PWM technique to maintain a step up constant dc output voltage with no polarity reversal, low ripple in output and minimizing the requirement of additional filter circuit and fed to single phase inverter. This paper has been focused for the overall single phase PV based SEPIC inverter system implementation, performances and simulated on MATLAB/SPS software to provide low losses, 2% minimum THD and reliable operation in compare with single phase PV based Cuk inverter is used for DC-AC conversion system to compatible with domestic load appliances.

Perforated Steel Stud to Improve the Acoustic Insulation of Drywall Partitions

Steels studs are an inevitable part of drywall construction as they are lightweight and offer the required structural stability. However, the studs act as sound bridges between the plasterboards reducing the overall sound insulation of the wall. Overcoming this often calls for wider cavity walls and complex stud decoupling fixtures that increase the installation cost while reducing the floor area. As an alternative approach, this research reveals the potential of perforated studs to improve the acoustic insulation of drywall partitions. The acoustic and structural performance is characterized using a validated finite element model that acted as a prediction tool in reducing the number of physical tests required. The results established that an acoustic numerical model featuring fluid-structure-interaction can predict the weighted sound reduction index of a stud wall assembly at an accuracy of ±1 dB. The model was used to analyze six perforated stud designs and found to outperform the sound insulation of non-perforated drywall partitions by reducing the sound bridging. Overall, the best performing perforated stud design was found to offer improvements in acoustic insulation of up to 4 dB, while being structurally compliant.

Optimal Capacity And Flow Assignment For Self-Healing ATM Networks Based On Path Restoration: Nonlinear Models

This thesis addresses the design of self-healing Asynchronous Transfer Mode (ATM) networks which is a special aspect of a more general problem, referred to as capacity and flow assignment (CFA) problem in self-healing ATM networks. We have proposed two nonlinear mathematical models for global reconfiguration strategy and failure-oriented reconfiguration strategy in our thesis. Our restoration strategies aim to minimize the capacity installation cost and the routing cost when a single link failure occurs in the network. A special case of the augmented Lagrangian method so-called Separable Augmented Lagrangian Algorithm (SALA) is proposed for solving the proposed nonlinear mathematical models. Numerical results are presented comparing the two restoration strategies in terms of five performance metrics which are capacity installation cost, total required capacity, routing cost, total network cost and required CPU time for convergence of the algorithms. Our results show that the global reconfiguration strategy has always performed better than the failure-oriented reconfiguration strategy for all the network scenarios, topologies and bandwidth requirements.