In 2022, Idaho stood fourth among U.S. states in renewable electricity share, with 74% generated from renewable sources like hydro, solar, wind, and geothermal. The dominant contributor has historically been hydropower. However, due to population growth and limited potential for new dam sites, reliance on solar and wind energy has increased. This paper aims to document the evolution of Idahoan public opinion regarding renewable energy's role in electricity production over 35 years. Public surveys were conducted every five years from 1987 to 2022, each involving at least 500 respondents. The surveys reveal strong public support for enhancing Idaho's renewable energy share. Over 75% of respondents expressed pride in the state's renewable electricity generation. Support for solar and wind energy has grown from 60% in 1987 to over 80% in 2022. Geographical preferences emerged, with south-western and south-central residents favoring solar, south-eastern residents favoring wind, and northern residents divided between hydro, solar, and wind. The surveys disclose that Idahoans: (1) strongly support increased renewable electricity production, (2) endorse solar and wind energy as key contributors, and (3) desire to replace Idaho’s remaining non-renewable energy production with renewable sources within the next decade.

The electrification of naval propulsion systems is increasingly investigated as a promising avenue to reduce CO₂ emissions. This study explores the application of electric propulsion in diverse waterborne transport sectors, ranging from commercial and industrial cargo ships to naval vessels, passenger cruise liners, ferries, and small recreational boats. In these systems, propellers are powered by large electric motors, which are progressively transitioning to induction or synchronous multiphase solutions. A crucial component of these systems is the Battery Storage System (BSS), which is integrated with an energy storage management system to create a grid that powers the electric motors. The BSS is integral to the vessel's operational autonomy, providing consistent energy for continuous operation. A Hybrid Energy Storage System (HESS) composed of two or more battery packs with varying characteristics may be deployed to prevent battery oversizing. This system comprises cells with different technologies, specifically interconnected through distinctive Battery Management Systems (BMSs) and converters. This paper delves into the key challenges and optimization of HESS modular solutions, outlining the energy storage requirements and management strategies necessary for diverse vessel working cycles. Simulation results are presented to demonstrate the system's ability to supply a realistic 10-hour load cycle, even when starting from State of Charges (SOCs) unbalanced by over 30%. These findings illuminate the potential of HESS solutions in maintaining effective and sustainable electric propulsion in naval transport systems.

In pursuit of achieving developed country status by 2041, Bangladesh is committed to comprehensive socioeconomic development—a goal intrinsically tied to the critical task of securing a reliable, uninterrupted energy supply while optimizing utilization of available energy sources. This study used 1980–2018 annual data to examine the implications of energy transition and causal relationships among economic growth, renewable energy, and natural gas consumption in Bangladesh. A rigorous two-step process investigated the causal correlations among variables. The autoregressive distributive lag (ARDL) model was used to scrutinize long-term relationships, while a vector error correction (VEC) model was used to ascertain the directionality of these causal relationships. The outcomes of the bound tests conclusively revealed the presence of a long-run equilibrium relationship among the variables. Causality analyses indicated a unidirectional causal relationship from renewable energy consumption to economic growth in the long run and from natural gas consumption to economic growth in the short run. A bidirectional causal relationship was found between natural gas and renewable energy consumption in the long run. These findings underscore the potential of energy conservation strategies to catalyze economic growth and suggest an avenue for Bangladesh to achieve its ambitious socioeconomic development goals.

Anaerobic digestion (AD) is a versatile process that entails low energy consumption and has low capital costs. Unfortunately, this process is not widely commercialized due to instabilities. The instability in the system is due to variations in the feedstock, operating, and environmental conditions. Therefore, this study aimed to determine the effect of organic loading rate (OLR), temperature, and pH on the AD system. An online pH and temperature monitoring sensor calibration were also studied to adjust AD parameters. The water quality parameters that were monitored were turbidity, chemical oxygen demand (COD), and colour. Wastewater with a low and high organic loading had a 90% and 36% COD reduction respectively after 5 days. Without pH adjustment, the pH of the system was 4.1 to 4.4 and the maximum COD reduction was 56.2%. When the pH was increased to 6.8, the maximum COD reduction was 66.5%. For the unadjusted temperature (room temperature), a maximum COD reduction of 56% was achieved. When the temperature was increased to 40℃, the maximum COD reduction was 66%. The increase in pH and temperature resulted in a 10% increase in COD reduction in the AD system. From the study, online pH, and temperature sensor calibrations errors were found to be 0.5 and 0.05 respectively as compared with the manual analytical technique. One of the limitations of this study was obtaining the apparatus to control temperature and pH at the same time. Future research will involve the automation of the AD system will the determined optimum conditions. This suggests smart monitoring and control sensors of AD operational parameters can repurpose its reliability for commercial activity.

Solar energy, as the most abundant renewable energy source, has garnered significant attention for its potential in electricity generation. Photovoltaic (PV) panels, capable of converting solar energy into electricity, have been widely considered for residential applications, including on-grid and off-grid systems. This study seeks to evaluate the economic feasibility of implementing on-grid and off-grid solar PV systems in residential settings through a case study in Gemolong, Sragen. The Hybrid Optimization Model for Electric Renewable (HOMER) software is employed to simulate these systems, providing an economic analysis over a specified time period. Results indicate that the on-grid system presents a more favorable option for the Gemolong region, owing to its optimized monthly production, minimal maintenance costs, and investment potential. The total installation cost for the on-grid system is estimated to be Rp 64,985,200.00, compared to the off-grid system’s cost of Rp 745,731,208.82. Furthermore, the on-grid system demonstrates a 13.3% advantage in energy production. Based on the energy and economic analyses, the on-grid PV system is recommended for adoption in the Gemolong area.

University campuses in Iraq are substantial energy consumers, with consumption increasing significantly during periods of high temperatures, underscoring the necessity to enhance their energy performance. Energy simulation tools offer valuable insights into evaluating and improving the energy efficiency of buildings. This study focuses on simulating passive architectural design for three selected buildings at Al-Khwarizmi College of Engineering (AKCOE) to examine the effectiveness of their cooling systems. DesignBuilder software was employed, and climatic data for a year in Baghdad was collected to assess the influence of passive architectural strategies on the thermal performance of the targeted buildings. The simulations revealed that the implementation of passive architectural design in AKCOE buildings led to a decrease in energy consumption for cooling purposes. Energy savings were achieved through natural ventilation, which minimized heat gain, and by employing continuous sun protection with double-glazed windows. By adopting a passive cooling strategy in AKCOE facilities, annual energy consumption for cooling within the campus could potentially be reduced by up to 23.6 percent. In conclusion, it was found that the current glazing system utilized in Iraqi building construction significantly contributes to electrical energy consumption.

Geothermal energy, an efficacious and readily available resource, has emerged as a sustainable alternative poised to satisfy escalating global energy demands. This study undertakes a comprehensive analysis of low (heat below 100℃) and medium (heat between 100℃ to 150℃) enthalpy geothermal energy through a bibliometric approach and a literature survey, with an emphasis on the environmental and economic aspects. The methodological procedure encompasses: (i) systematic information processing and configuration, (ii) bibliometric assessment of the evolution and domains of the investigated field, (iii) evaluation of environmental and economic contributions, and (iv) Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis, facilitated by a Focus Group comprising experts from the energy sector. The research on low and medium enthalpy geothermal energy has been identified as an expanding field, with five primary areas of focus: sustainability, cascade systems, heat pumps, numerical modelling, and groundwater potential in geothermal systems. Italy, the United States, and Germany have been recognized as the leading contributors in terms of scientific production. Geothermal energy, from an environmental standpoint, aids the decarbonisation process, reducing reliance on fossil fuels and other renewable energy sources. Although initial investment costs are considerable, the financial recovery period is relatively short. The promotion of geothermal energy, alongside the active involvement of academia, corporations, and governments, bolsters energy and socio-economic development, thereby contributing to the achievement of the Sustainable Development Goals (SDG).