Vertical-axis wind turbines (VAWTs) offer a promising solution for generating electricity from wind energy, particularly at low wind speeds. Enhancing the design, structure, and material properties of VAWTs can significantly improve their mechanical performance and aerodynamic efficiency. This study aimed to validate a small VAWT design optimized for low wind speeds using computational fluid dynamics (CFD) analysis. The primary focus was to confirm the simulation results against experimental data from an existing Savonius 2-blade wind turbine operating in the 6–12 m/s speed range. The results demonstrated a high level of consistency between simulation and experimental data, with an error margin of 20
This research focused on the application of a centrifuge combined with a biodiesel washing machine with biochar in biodiesel production. This method aims to reduce the amount of biochar used in the washing process to meet biodiesel standards. Therefore, the research aimed to improve the biodiesel production process by using a centrifuge machine combined with the biochar washing method (CB) and comparing it with two methods: gravitational settling combined with water washing (GW) and gravitational settling combined with biochar washing (GB). The results indicated that the CB method could reduce contaminants in biodiesel. Although the biodiesel yield did not differ from the GB method, it remained higher than the GW method, increasing the biodiesel yield by up to 1.19
Renewable energy consumption has emerged as an energy source that can reduce concerns about greenhouse gas emissions. However, renewable energy generation is less attractive due to its expensive and capital-intensive nature. Countries with lower development levels or individuals with limited capabilities experience increasingly severe negative impacts from environmental changes, leading to health and economic crises. One region that needs to overcome the Middle Income Trap is ASEAN. This study uses the period from 1995 to 2020 with renewable energy as the dependent variable. Gross Domestic Product (GDP), Foreign Direct Investment (FDI), population, and CO2 Emission serve as independent variables, using VECM as the analysis technique. The results show that GDP, FDI, and CO2 Emissions have a significant positive ef, whereas population has a significant negative effect on renewable energy. In the short term, FDI and population significantly positively affect renewable energy. To promote renewable energy development, governments must focus on increasing GDP and attracting FDI, especially in the clean energy sector. Thus, renewable energy generation continues to progress.
Drying is one of the main factors for a quality post-harvest process with high selling value. Farmers in Pacitan, Indonesia, and most farmers in developing countries are highly dependent on weather and rainfall in the drying process of agricultural products. The Pacitan Regency Government has also built a drying system for agricultural products. However, this drying system is not optimal during the rainy season because Pacitan has high rainfall. Therefore, the Dryer Dome technology is adopted with a hybrid source of sunlight and renewable biogas energy called Smart Bio Dryer Dome (SBDD). In general, agricultural communities need evidence of the success of the technology to be willing to adopt it. Therefore, the research team conducted a feasibility study of SBDD innovation in increasing agricultural productivity in Pacitan Regency. The method used in the study was Participatory Action Research (PAR). The data taken was a Smart Bio Dryer Dome Technical Analysis, a business feasibility analysis that included the ratio of revenue to cost, benefit to cost, the internal rate of return, the net present value, and the payback period. In addition, environmental impact analysis data was also taken through the measurement of changes in methane emissions from cattle waste. The results showed higher IRR and NPV values, faster payback period values, as well as better revenue-to-cost and benefit-to-cost values for a longer period of use of the Solar Dryer Dome.
Generating renewable energy locally in urban areas is vital for achieving sustainable development goals (SDGs). Small wind turbines are increasingly recognized as practical and effective solutions for harnessing renewable energy in urban environments. This research employed Computational Fluid Dynamics (CFD) to investigate an urban area earmarked for wind turbine installation, specifically focusing on buildings within the Faculty of Engineering at Mahidol University, Thailand. Velocity distribution was analyzed to simulate non-uniform airflow typical of urban wind conditions, considering various wind speeds and directions. The study revealed that the velocity field distribution varied significantly with different wind directions. Moreover, optimal rooftops for wind turbine placement were identified, highlighting the importance of strategic installations. Specifically, rooftops with turbulence intensity (TI) ≤ 0.15 were found suitable for horizontal-axis wind turbines (HAWTs) positioned 8.6 m above the EG3 building. Below this threshold, vertical-axis wind turbines (VAWTs) were recommended to harness flow recirculation within the roof area.
