This study provides a techno-financial evaluation of two sites in Malaysia: Kudat, located on the coast of the northernmost part of Sabah, the state of East Malaysia with promising wind potential, and Putrajaya in the Klang Valley region with moderate wind potential at high elevations similar to the dominant cities in Malaysia. Three small-scale wind turbines were evaluated, taking into account a nominal electrical power generation below 100 kW. The research is focused on 220 residential households. The software used to perform the evaluation was Hybrid Optimization of Multiple Energy Resources (HOMER). The research novelty is the examination of the non-hybrid small-scale turbines at high elevations for regions with low wind speed, such as Malaysia. Regardless of the wind farms’ financial profit, this study used the net present cost (NPC) analysis in all cases. This research demonstrates the feasibility of small-scale wind turbines mounted at high elevations for generating sufficient energy. The results indicate that in both areas, the RX-20KH3 model is the best option, and the costs of the FH-5000 and RX-20KH3 farms are proportionate for a renewable project. Furthermore, with government support, the WES80 farm could be suitable.

Radiant cooling systems (RCS) are gaining acceptance as a heating, ventilation, and air conditioning (HVAC) solution for achieving adequate thermal comfort and maintaining acceptable indoor air quality inside buildings. RCS are well known for their energy-saving potential; however, serious condensation problem hinders the growth of this technology. In order to prevent the risk of condensation, the supply water temperature is kept higher than the dew point temperature of the air inside the room. The full potential of the cooling power of a radiant cooling panel is limited. Therefore, this article is on maximizing the cooling capacity of a radiant cooling panel, in terms of flow configuration. Radiant cooling panels (RCP) with different chilled water pipe configurations are designed and compared, side by side with the conventional serpentine flow configuration. The cooling performance of the radiant cooling panels is evaluated by using computational fluid dynamics (CFD) with Ansys Fluent software (Ansys 2020 R2, PA, USA). Under similar flow and operating conditions, the common serpentine flow configuration exhibits the least effective cooling performance, with the highest pressure drop across the pipe. It is concluded that the proposed designs have the potential of improving the overall efficiency of RCP in terms of temperature distribution, cooling capacity, and pressure drop.

The Archimedes Spiral Wind Turbine (ASWT) is a promising candidate for urban wind energy applications due to its helical blade geometry, which enables stable rotation and efficient energy captured at low wind speeds. However, its aerodynamic performance remains limited and can benefit from targeted surface enhancements. This study proposes a novel blade surface design in which semi-cylindrical grooves or bumps are geometrically integrated into the suction or pressure sides of the ASWT blades to improve aerodynamic efficiency. Twelve ASWT configurations were systematically developed using parametric modeling in SolidWorks 2020 and evaluated through computational fluid dynamics (CFD) simulations in ANSYS CFX R2. Among the tested designs, the model featuring longitudinal grooves on the pressure side with 12 groove lines (FWPG-12) demonstrated the highest aerodynamic improvement, achieving an 8.3% increase in power coefficient (\(\:{\text{C}}_{\text{p}}\)) at a wind speed of 10 m/s. These improvements are attributed to improved flow attachment and delayed boundary layer separation. In contrast, blades featuring surface bumps showed no aerodynamic advantage and generally led to performance deterioration. The findings underscore the aerodynamic benefits of bioinspired surface modifications and highlight their potential for advancing ASWT performance in urban renewable energy systems.

The receiver is an important element in solar energy plants. The principal receiver’s tubes in power plants are devised to work under extremely severe conditions, including excessive heat fluxes. Half of the tube’s circumference is heated whilst the other half is insulated. This study aims to improve the heat transfer process and reinforce the tubes’ structure by designing a new receiver; by including longitudinal fins of triangular, circular and square shapes. The research is conducted experimentally using Reynolds numbers ranging from 28,000 to 78,000. Triangular fins have demonstrated the best improvement for heat transfer. For Reynolds number value near 43,000 Nusselt number (Nu) is higher by 3.5% and 7.5%, sequentially, compared to circular and square tube fins, but varies up to 6.5% near . The lowest friction factor is seen in a triangular fin receiver; where it deviates from circular fins by 4.6%, and square fin tubes by 3.2%. Adding fins makes the temperature decrease gradually, and in the case of no fins, the temperature gradient between the hot tube and water drops sharply in the planed tube by 7%.