Maximum Electrical Power Research Articles

Optimization of Turbine Blade Pitch Angle of a Home-built Wind Turbine for Maximum Power Output

Wind energy greatly reduces the world’s dependence on fossil fuels (oil and natural gas), and is environmentally friendly. One of the most cost-effective alternatives of energy sources is wind power. This study used a horizontal axis wind turbine to investigate the optimal blade pitch angle that can give maximum electrical output. A proportional integral derivative pitch controller was used to establish blade pitch angles. Wind speeds of 3, 4, 5 and 6 m/s were run at every pitch angle respectively, and a maximum electrical power output was 1124.7W at a blade pitch angle of 16.80 when a wind speed of 6 m/s was used. Every wind speed was run for 100 seconds. A simulation, using Visual Basic 6 software, was done at the respective blade pitch angles, and a wind speed of 6 m/s. The electricity produced was recorded. The simulated electrical power produced yielded a relationship that predicted the electrical power output with a coefficient of determination (R2) of 0.9752; this shows a very close agreement with actual electric output values.

Thermal and electrical performance analysis of a lightweight micro CHP system for recreational vehicles

For comfortable use of a Recreational Vehicle (RV), there is a need to supply electrical energy to recharge the batteries and supply the installed equipment, as well as thermal energy, for hot water and ambient heating. A conventional solution for supplying electrical energy is the installation of photovoltaic modules combined with connection to an electrical grid, when possible. Water heating is generally done using a passage gas heater or hybrid gas/electric storage heater. Imported vehicles have gas heating and many other vehicles have diesel heaters. To develop an alternative to currently available energy supply methods, this work proposes the creation of a cogeneration system for RVs. From a literature review, a research gap was identified in relation to micro CHP devices for RVs. In the development of this work, a micro CHP prototype was created, with 980 W of maximum electrical power, consisting of a single-cylinder internal combustion engine, an automotive alternator and heat exchangers for heat recovery. The prototype was enclosed and instrumented, allowing to evaluate the thermal power obtained in water flowing through exhaust gases, lubricating oil and cooling air heat recovery systems, in addition to measuring the electrical power of the alternator. Operational tests were carried out with 46 different test conditions, combining variations in the engine speed (N) and in electrical load. The prototype electrical efficiency reached 10.18 % ±0.2 % at 3008 rpm with 83 % load. The maximum electrical power was 0.746 kW±0.015 kW at 3637 rpm and 100 % load. The maximum thermal energy recovery rate was 3.267 kW±0.039 kW. Utilization factor reached 65.57 % ±0.33 % at 3208 rpm with 63 % load. Compared to traditional means of providing electrical power and thermal power for RVs, the prototype proved to be more advantageous when the demand is for electrical power and space heating. However, for conditions in which the demand is for electrical power and water heating, or just electrical power, the current solutions available are still more efficient.

Analysis of Single Diode Model of Solar Cell Simulated with MATLAB for Maximum Electric Power Extraction

Analysis of Single Diode Model of Solar Cell Simulated with MATLAB for Maximum Electric Power Extraction

Phononic crystals with incomplete line defects: applications in high-performance and broadband acoustic energy localization and harvesting

Using phononic crystals (PnCs) to enhance the electrical output performance of piezoelectric energy harvesting (PEH) devices and broaden the frequency range of harvesting energy is crucial to solving the self-energy of low-power devices such as wireless sensors. In this work, an ultra-wide full-band gap PnC was designed. The concept of a PnC with an incomplete line defect was proposed. The energy localization and harvesting of incomplete line defect PnCs and traditional point defect and line defect PnCs were studied by finite element analysis. The results show that compared with a point defect and a line defect, the output electric power of an incomplete line defect was increased by 31.88 times and 2.51 times, respectively, and the energy localization and harvesting frequency band were widened. By exploring the influence of the periodicity of the vertical incomplete line defect direction on the electrical output performance of the PnC-based PEH system, it is found that the electrical output performance of the 5 × 3 incomplete line defect PnC is the best, and the maximum output voltage and output electric power are 27.36 V and 17.29 mW, respectively. This work provides new insights and ideas for improving the energy localization and harvesting performance of PnC-based PEH systems.

Numerical Simulation of Geothermal Energy Development at Mount Meager and Its Impact on In Situ Thermal Stress

The Meager Mountain Geothermal Project stands as one of the pioneering geothermal energy initiatives in its early stages of resource development. Despite its abundant geothermal heat resources, no prior studies have systematically evaluated the potential of implementing coaxial borehole heat exchangers on site. This study addresses this research gap by presenting a comprehensive heat transfer model for an underground closed-loop geothermal system utilizing a single coaxial well. Finite element analysis incorporated fluid and solid heat transfer, as well as solid mechanics. The results obtained facilitated the construction of the temperature and thermal stress profiles induced by the cooling effects resulting from years of heat extraction. After 25 years of operation, the outlet temperature has reached approximately 74 °C, and the maximum radial tensile thermal stress amounts to ~47 MPa. Furthermore, the analysis demonstrates that higher fluid velocities contribute to more perturbed temperature and stress distributions. The study attained maximum thermal and electric power outputs of 208 kW and 17 kW, respectively. This research also underscores the significant impact of geothermal gradient and well length on BHE design, with longer wells yielding more power, especially at higher injection velocities.

Electrical power, energy efficiency, NO and CO emissions investigations of an ammonia/methane-fueled micro-thermal photovoltaic system with a reduced chemical reaction mechanism

Ammonia is an alternative renewable green fuel with significant potential for addressing climate change concerns. Blending ammonia with methane has emerged as a viable strategy to improve the laminar burning velocity of ammonia. In this study, we propose a mechanism for methane/ammonia combustion, comprising 31 species and 131 chemical reaction steps, and investigate the emissions of CO and NO, along with electrical power output and energy efficiency of a micro-thermal photovoltaic (MTPV) system fueled with premixed ammonia/methane/oxygen. Three key parameters are identified as: 1) the inlet mixture flow velocity, 2) the CH4 mole fraction blended ratio (ξCH4), and 3) the material of the micro-combustor. The MTPV system achieves its highest energy efficiency (5.8 %) at an inlet velocity (vin) of 2.3 m/s, and reaches its maximum electrical power output (6.9 W) at vin = 7.2 m/s. Further, increasing ξCH4 can enhance electrical power output (ξCH4 = 0.9 yields 1.37 W more than that at ξCH4 = 0.1). Finally, altering the micro-combustor material is shown to have little effects on electrical power output, NO emissions, and energy efficiency. However, the MTPV system made of quartz is found to reduce CO emissions by 15 % and 12 % in comparison with those systems made of Sic and steel, respectively.

Development of a Solar-Powered Barley Sprouting Room

The study aims to develop a sprouting room for barley powered by solar energy instead of traditional alternating-current rooms to suit remote areas. The cooling, lighting, and irrigation systems were developed and replaced with another that operates on 12 V DC. An air cooling device based on the Peltier module has been developed as an alternative to air conditioning devices. Four cooling units of the air cooler were tested with three lighting durations of 6, 9, and 12 h and three irrigation rates of 1.7, 1.85, and 2 m3 ton-1. The measurements included evaluating the performance of the developed air cooler device. The vegetative and quality characteristics and a chemical analysis of sprouted barley for the solar-powered room compared to the room before the modification were estimated. The solar room's productivity and electrical energy consumption rates were estimated, and an economic evaluation of the development was conducted. The maximum electrical power consumption for the solar-powered sprouting room was 63.275 kWh ton-1, compared with 117.19 kWh ton-1 for the alternating current-managed room before modification. The interaction between the utilized developing DC air cooling, lighting, and irrigation achieved standard rates for the produced barley vegetative and quality characteristics. The maximal productivity from sprouted barley was 1.22 tons, per 7 days with an increment ratio over control of 31.97%. The net earnings for the developed sprouting room were maximized relative to the significant decrease in electrical production costs. The developed room fits the livestock sector by providing good economic alternative fodder sources.

Binary Vapor Cycle for Waste Heat Recovery from Marine Engine Exhaust

Abstract The considerable energy waste in maritime transport and the need to obtain alternatives to reduce emissions of polluting gases are factors that have motivated the study of waste heat recovery systems for marine engines. The system studied herein relies on a binary vapor cycle that uses water for the topping cycle while three organic fluids were investigated for the bottoming cycle: R601a, R134a, and R22. Each of these belongs to a different category of fluid, namely, dry fluid, isentropic fluid, and wet fluid, respectively. Two engines of different ratings and two different pressures of the heat recovery steam generator have been considered for each engine. Various outlet pressures for the topping turbine, which is the most liable to erosion and corrosion due to wet steam, have been investigated. The maximum efficiency achieved for the waste heat recovery system peaked at 21% while the maximum electric power accounted for 4.2% of engine brake power. Therefore, the employment of a waste heat recovery system based on a binary cycle seems a promising alternative to harnessing heat from the exhaust gases of marine engines.

Influence of length of resonance tubes on multi-stage looped thermoacoustic electric generator

Resonance tubes are often used to connect multi-stage looped thermoacoustic heat engine and linear alternators to form a multi-stage looped thermoacoustic electric generator. In this paper, we experimentally investigate the performance of a multi-stage looped thermoacoustic electric generator with two sets of resonance tubes of different lengths. With the increase of the length of resonance tubes from 1.5 m to 2 m, the system frequency decreases from 70 Hz to 62 Hz. The maximum output acoustic power increases from 6.97 kW to 8.16 kW, and the maximum output electric power increases from 5.09 kW to 6.24 kW. Meanwhile, the maximum thermoacoustic efficiency increases from 23.08 % to 23.94 %, the maximum acoustic-to-electric efficiency increases from 78.03 % to 82.06 % and the maximum thermal-to-electric efficiency increases from 17.79 % to 19.64 %. Numerical simulation is also conducted based on a 3-step coupling method and validates the experimental results. This study demonstrates that adjusting the length of resonance tubes in a multi-stage looped thermoacoustic electric generator is an effective way to tune the frequency as well as to improve the coupling between the multi-stage looped thermoacoustic heat engine and linear alternators.

Design and experimental study of a 300 We class combustion-driven high frequency free-piston Stirling electric generator

Portable electric power generator with a power level of several hundred Watts plays an important role in outdoor activities, emergency relief and tactical power supply. As an external-combustion heat engine with outstanding heat source adaptability, free-piston Stirling generator (FPSG) owns attractive advantages of quietness, high thermal efficiency, and high reliability. This paper proposes a novel ultra-high frequency (UHF) FPSG-based portable power supply system driven by a diesel porous media evaporative combustor (PMEC). An experimental setup was designed and built based on the quasi-one-dimension thermoacoustic impedance matching of the FPSG and three-dimension thermal coupling of steady combustion and alternating flow between FPSG and combustor. The fundamental operating characteristics of the system were investigated in terms of combustion powers and electric loads. Preliminary experimental results show that a maximum output electric power of 350 We at a heating temperature of 875 K and a maximum fuel-to-electric efficiency of 11.98 % were obtained. Computational fluid dynamics (CFD) simulations were employed to delve into the intricate combustion and heat transfer processes, unveiling the formation of carbon deposits and confirming the efficacy of cyclone holes in reducing carbon deposition. This pioneering exploration of 130 Hz UHF and evaporative-combustion coupled heat transfer successfully showcases the feasibility of constructing a high-specific-power FPSG-based portable power system.

Enhanced photovoltaic response in WSe2 photodetector with asymmetric two-dimensional contacts

Asymmetric contact pairs with different work functions provide an efficient method to extract photogenerated carriers in optoelectrical devices. Specifically, vertical optoelectrical devices based on two-dimensional (2D) materials utilize graphene layers as the bottom and top contacts. Whereas an additional terminal is required for electrostatic doping in either top or bottom graphene to enlarge the built-in electric field. Herein, we present an enhanced photovoltaic response in a vertical WSe2 photodetector utilizing asymmetric 2D contacts. A graphite layer and a degenerate SnSe2 are used as the top and bottom contacts, respectively, with a significant difference in their work functions. By establishing a large built-in electric field across the vertical WSe2 layer, a strong photovoltaic effect is achieved, resulting in an open-circuit voltage of 0.37 V and a short-circuit current of 0.42 μA under 532 nm illumination. The device shows high-performance photodetection characteristics, with a responsivity of 32.04 A W−1, external quantum efficiency of 7475%, and specific detectivity of 3.61 × 1012 Jones. Furthermore, the device can generate a maximum output electrical power of 70.9 nW, enabling a high-power conversion efficiency of 3.5%.

Design and numerical simulation of a 45 kWel multi-source high-flux solar simulator as a heating source of dielectric materials positioned in a microwave characterization cavity

This study reports the design and modelling of a high-flux solar simulator (HFSS) combined to a resonant cavity for microwave dielectric properties characterization of ceramics at very high temperatures. The HFSS comprises seven xenon arc lamps with ellipsoidal reflectors, delivering a maximal electrical power of 6.5 kWel each. Positioned on a virtual sphere of around 1600 mm radius, the lamps provide concentrated irradiation heating on a sample positioned inside the resonant cavity. The propagation of the lamp’s irradiation to the sample and the cavity is simulated using Monte Carlo ray tracing method. An ANSYS Fluent finite volume method for solving the resulting multimode heat transfer and flow indicate a radiative flux reaching 1.84 MW m−2, and a sample temperature of approximately 1470°C with 10 % non-uniformity. These results suggest that the designed heating system and resonant cavity is suitable for conducting microwave dielectric properties characterization of refracting ceramic materials at high temperatures, addressing a gap in studies focusing on temperatures exceeding 1000°C.

Pengolahan Lahan Pertanian Menggunakan Internet of Things di Desa Wukirsari, Sleman

Tri Sedyo Manunggal Farmer Group in Wukirsari Village, Sleman Regency, Yogyakarta faces challenges in managing agricultural land. The irrigation system is still done manually, while the source of electricity to drive the water pump still depends on PLN electricity and fuel. As a solution, an internet of things is needed that can monitor soil pH, humidity, temperature, and leaf color and can be accessed remotely. The irrigation system is automatic, and the power source is obtained from solar panels to drive the water pump to lift water from the well to the output pipe. Four solar panels are used, each panel has a power of 230 watts peak, a solar charge controller with a capacity of 50 amperes, two soil pH sensors, two humidity sensors, two temperature sensors, and two color sensors. The battery used is a 12-volt Valve Regulated Lead Acid (VRLA) type with a capacity of 100 Ah. A water pump with a capacity of 300 watts with a water discharge of 47 liters per minute can meet the water needs of 1 ha of agricultural land in about 3-4 hours. The maximum electrical power generated by solar panels under maximum sunlight conditions is 920 watts peak, with a maximum current of 11.79 amperes and a maximum voltage (Vmp) of 19.5 volts. Then the solar panel will charge the battery in an empty condition for about 90 minutes in 80% sunlight efficiency conditions.

Performance assessment and comparison of a catalytic steam reforming enhanced closed-brayton-cycle power generation system for hypersonic vehicles

Hypersonic vehicles as next-generation aircraft have broad applications, but existing technologies of onboard power generation are hardly applicable due to the change of engines. In this research, a catalytic steam reforming enhanced closed-Brayton-cycle power generation system based on is developed. This system combines the closed Brayton cycle (CBC) and catalytic steam reformed fuel vapor turbine (CSRFVT) to supply electric power. The zero-dimensional models of CBC and the CSRFVT are established to evaluate system performance. Results indicate the products with a water content of 30% have the strongest working ability, which can reach 330 kJ/kg. Moreover, the thermal efficiency and electric power of the parallel arrangement are higher than that of the series arrangement. Besides, the lower pressure of water is beneficial to the electric power. However, the difference in electric power between various pressures is less than 1 kW. In addition, under the same heat absorption, the total electric power of the system based on fuel and water is higher, and the former's outlet temperature of cooling channels is lower. The maximum total electric power of the novel system is about 120 kW. This research provides an innovative technical solution for the power generation of hypersonic vehicles.

Optical, electrical, and thermal performance of low-concentrating photovoltaic/thermal system using microencapsulated phase change material suspension as a coolant

Concentrated photovoltaic/thermal (C-PV/T) systems exhibit superior output compared to common PV/T collectors. To address potential issues caused by excessive concentration of conventional parabolic concentrators and enhance the electro-thermal co-generation capability, this work proposes a low-concentrating PV/T (LC-PV/T) system that integrates two improved concentrator designs and a coolant of microencapsulated phase change material suspension (MPCMS). A numerical model is established to investigate the effects of working conditions and meteorological conditions on the optical, electrical and thermal performances. The results indicate that the improved concentrator designs effectively prevent over-concentration of sunlight while maintaining a comparable concentration ratio (CR). The electrical output increases with an increase in mass fraction, inlet mass flow rate and solar irradiance, but decreases with an increase in ambient temperature and inlet temperature. Conversely, thermal output increases with an increase in all of these parameters except for the inlet temperature. This system can achieve 17 % electrical efficiency and 72 % thermal efficiency due to the high-efficiency solar cells, optimized concentrator design, and unique MPCMS coolant. The system can produce a maximum electrical power of 4.76 kW/m2 and a maximum thermal power of 19.53 kW/m2. Throughout the day, total electrical and thermal energies are approximately 4.1 kWh and 58.8 MJ.

The output performance evaluations of multilayered piezoelectric nanogenerators based on the PVDF-HFP/PMN-35PT using various layer-by-layer assembly techniques

Multilayered Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and lead magnesium niobate lead titanate Pb (Mg1/3Nb2/3) O3–PbTiO3 (PMN-35PT) composition-based piezoelectric nanogenerators (PNGs) were fabricated as series, parallel, and combined series-parallel connections using various layer-by-layer assembly techniques. Supporting the theoretical approaches with experimental results shows that the fabricated four-layered PNG with parallel connections (4L-P) reached an open-circuit voltage of 0.4 V (VRMS) and a maximum electrical power of 0.3 µW (PRMS) by drawing a current (IRMS) of 1.46 µA under a resistive load of 140.2 KΩ. Increasing the capacitance and decreasing the impedance with the fabrication of the four-layer PNG by connecting the layers in parallel connection with the support of the impedance matching process led to an increase in electrical output. With the use of an impedance matching system, the piezoelectric performance tests revealed that the 4L-P-based PNG had a 6.7 times greater electrical power efficiency (72.92 µW) at the vibrational frequency of 20 Hz compared to that of the single-layered PNG (10.82 µW). Furthermore, the multilayer PNG was successfully used as a wearable sensor for the monitoring of human body motions in real time on an IOT (Internet of Things) platform.

Derivation of a Sun-tracking law for payloads with pointing restrictions in the UPMSat-3 mission

Satellites dedicated to remote sensing either for the Earth or space, typically require their instruments to be pointing toward the location of their object of study. These satellites can face significant challenges as different components also have its own pointing requirements to be operative or work optimally. For instance, we have the case of solar panels for electrical power generation, where perfect pointing of the panels toward the Sun can affect negatively to payload operation. Common solutions for maximizing power generation include the usage of orientable solar panels. However, this approach increases the complexity of the satellite, raising the cost of the solar panels and their associated mechanism. In this study, we propose a new approach that enables high-consuming remote sensing payloads to operate for extended periods without using orientable solar panels. To ensure maximum power generation without compromising the satellite’s pointing constraints, an optimal tracking law is derived. This law maximizes the projected solar array area at each instant, resulting in maximum electrical power generation. The proposed method is validated against an actual mission scenario. This work offers significant benefits for satellite operators, reducing the need for costly orientable solar panels and enhancing the overall efficiency of satellite missions.

Transmitter design and AE–AR region characterization for NOMA-SLIPT UWOC systems with uniformly distributed message and Imp-SIC

This paper investigates simultaneous lightwave and information transfer (SLIPT) based non-orthogonal multiple access (NOMA) in underwater optical wireless communication (UWOC) systems. At the user signal separation (SS) based SLIPT scheme is employed. Imperfect successive interference cancellation (SIC) at the near user is considered. Firstly, we derive the maximum allowable electrical power for message symbols at the transmitter, ensuring input to the laser diode lies within the linear region and. A novel linearity-constrained transmitter design is proposed for the uniformly distributed message, followed by calculations of instantaneous data rate and instantaneous harvested energy for both users. Then, closed-form expressions for average data rates (AR) and average energy harvested (AE) under weak turbulence-induced fading channels using Holtzman’s approximation are derived. The tightness of the approximation is confirmed by Monte-Carlo simulations. AE–AR boundaries for both users show an initial rise and subsequent decline in data rates with increased harvested energy, owing to higher bias values restricting transmitter power. The study also examines trade-offs between AE and AR across various system parameters including beam divergence angles, imperfection of SIC, power allocation coefficients, and water types, is conducted. We observe shifting and shrinking/expansion of the AE–AR region depending upon the variation of the various system parameters. We also show that the discussed SS scheme is general and encompasses time-switching (TS), and power-splitting (PS) schemes as special cases. We also briefly discuss as to how the developed framework could be extended to more than two users. In summary, the overall effective energy consumption deduces owing to the adoption of SLIPT at the users, making the considered setup more energy-efficient.

Design and analysis of a PAM launcher at 4.6 GHz for a new LHCD system on EAST

To improve the Current Drive (CD) capability in long-pulse (up to ∼1000 s) H-mode operation, it has been decided to develop a new Lower Hybrid Current Drive system at 4.6 GHz with an active cooling Passive Active Multijunction (PAM) launcher on EAST. In this paper, both the radio frequency (RF) and the physical properties of this PAM are studied numerically. The same nominal parallel refractive index (N || = k ||c/ω, where k || is the parallel wavenumber, c the velocity of light, and ω the wave angular frequency) of 2.04 as the existing 4.6 GHz Full Active Multijunction (FAM) is chosen. Ray-tracing calculations indicate that good accessibility could be achieved when the LH waves radiate with this nominal N || in typical long-pulse H-mode plasmas. The coupling performance in terms of power reflection coefficient (R C), power spectrum, maximum electric field, power directivity (D P) and global CD capability is evaluated with the ALOHA code based on the linear coupling theory. Good coupling performance with averaged R C ⩽ 1% and D P ∼ 70% could be expected with the density (n e) in front of the PAM close to the cut-off value (n e_co). The simulated R C remains below 6.5% over a wide density range 0.5 ⩽ n e/n e_co ⩽ 10, which is similar to the plasma edge conditions produced by Edge Localized Mode activity. A detailed comparison with the existing 4.6 GHz FAM launcher is also performed.

Performance evaluation of looped tube thermoacoustic power generator using cyclic analysis

This paper focuses on the numerical and experimental investigation of the small-scale power generator. The travelling wave thermoacoustic power generator is numerically analyzed and experimentally tested. The cyclic analysis is used to carry out numerical analysis of the power generator. The system is operated on atmospheric pressure, which allows the manufacturing of an acoustic feedback loop using Polyvinyl chloride piping. The acoustic power generated inside the generator is harnessed by the low-cost linear alternator, i.e., loudspeaker. The effect of regenerator wire mesh on performance of the power generator is numerically analyzed and validated experimentally. The numerical analysis identifies the temperature variation, pressure fluctuation, volume flow rate inside the system, and acoustic power distribution. The maximum electric power experimentally generated by the small-scale power generator is around 45 W with overall efficiency 8.30%. The alternator generates the maximum electric power at the optimum location, i.e. 2.30 m away from the engine core.