Usable Power Research Articles

Powering India’s Blue Economy through ocean energy

ABSTRACT With an increasing demand for ocean resources to fulfil the needs of an ever growing population, humanity has been pushed to utilise the ocean resources. To be successful in these efforts, they have been pushing technological development which in turn has increased the demand for power as most of these developments are power hungry. However, with the present power generation knowledge confined to fossil-fuel, achieving sustainability has been limited and a challenge to achieve. To overcome this limitation and to harness the full potential of the ocean-based Blue Economy, countries around the world, including India, are making concerted efforts to develop sustainable technologies to generate usable power from ocean-energy. Accordingly, the options available for utilising ocean-based renewable energy technologies to sustainably power growth through economic activities in the marine and coastal domain while being a meaningful contributor to the blue economic growth is discussed. In doing so, a global perspective of the status of the Blue Economy of marine renewable energy technologies with a focus on the opportunities for India has been provided. The article concludes with some suggestions of future developments for developing countries like India to meet the targets of powering their Blue Economy.

Power Generation from an Elastic Leidenfrost Hydrogel Piston Enabled Heat Engine

Leidenfrost phenomenon has been observed since 1756. Diverse Leidenfrost phenomenon based heat engines were developed for converting the thermal energy into mechanical form. Limited to the weak force, the Leidenfrost heat engines are rarely reported with usable electric power output. Here we propose an elastic Leidenfrost heat engine based power generator for the demonstration of thermal-to-electric power conversion. A saturated sodium polyacrylate super absorbing polymer sphere is employed as hydrogel piston for harvesting thermal energy to trigger elastic deformation and mechanical bouncing. A lightweight contact separation mode triboelectric nanogenerator (TENG) plays a role for the conversion from the tiny mechanical input into usable electric power. The dynamics of the hydrogel piston on hot plates, force generation during bouncing and electric power output are measured experimentally. The effects of piston stroke, working temperature, and water absorption rate of the hydrogel piston are discussed. A maximum open-circuit voltage of 22 V and peak power of 280 μW was obtained by a single 2-gram hydrogel piston and the output electric power from the hydrogel piston based power generator successfully lights up 22 commercial LEDs.

Performance study of a new smart hybrid parabolic trough collector system integrated with hybrid tubular thermoelectric generator

Advanced parabolic trough systems are the promising technologies for the production of usable heat and electrical power. Here we study the effects of hot water temperature adjustment concept and optical concentrator on the thermal and electrical efficiencies of a new PTC/HTTEG configuration, which comprises parabolic trough concentrator and hybrid tubular thermoelectric generator. The hybrid tubular thermoelectric generator (HTTEG) was integrated within the collector tube, where the hot water is passed between the inner side of the absorber tube and the top surface of the HTTEG. Meanwhile, to create a large temperature difference across the HTTEG sides, a cold water is passed along the inner side of the HTTEG. A low consumption pump was energized using HTTEG power in order to keep the hot water temperature at 95 °C for a long time (temperature adjustment concept). Numerical simulations show that the improvement in performance of the hybrid system highly depends on the adjustment concept and optical concentrator. As the solar concentration ratio increases, the overall efficiency of the hybrid system increases significantly to 76.21% and the amount of hot water reaches to a maximum value of about 846.77 Liter/Day for a concentration of 30 suns. Also, the power generated by the HTTEG and hot water temperature stay stable at 71.37 W and 95 °C, respectively, due to the hot water temperature adjustment effect. To validate the results of numerical model, a new validation method was proposed and discussed. The comparison of results obtained with results of the exact solution indicates a good agreement.

Piezoelectric Energy Harvesting Methodologies using Ambient Mechanical Vibration: Design Perspective and Challenges

Background and Objective: Piezoelectric energy harvesting is an emergent research area for unobtrusive power supply for fully autonomous micro-scale devices. Method: The method of energy harvesting is to utilize waste ambient mechanical vibrations to generate electrical energy through the piezoelectric effect. Results and Conclusion: The present work highlights the major advances made in the field of micro- electromechanical systems based on piezoelectric energy harvester on extracting ambient vibrations and converting them into usable electric power. The present study explores energy harvesting approaches for portable electronics and self-powered wireless network nodes. The performance matrices like device physics, volume, operating frequencies, design and materials have been thoroughly analyzed in this work. Conventional cantilever fabrication steps have also been discussed. Finally, guidelines for future research and performance enhancements in the field of Piezoelectric Energy Harvesting (PEH) at micro scale have been discussed.

Watt-level SHG in undoped high step-index PPLN ridge waveguides

Nonlinear quadratic waveguides are key components to obtain efficient frequency conversion. In this paper we present the performances of highly multimode periodically poled lithium niobate (PPLN) ridge waveguides for high power CW SHG are presented. We report the generation of 1 W of second harmonic on the fundamental guided mode with a conversion efficiency of 56% at telecom wavelengths. A stable nonlinear process is obtained despite use of an undoped congruent LiNbO3 crystal. The input damage threshold of the ridge waveguide is found to set the maximum usable power.

Micro glass welding with millimeter‐long filaments

AbstractThe welding of glass with ultrashort‐pulsed lasers (USP) is usually conducted with microscope objectives. Their short working distance limits the thickness of the work piece, the usable laser power and the feed rate of the process. To increase the possible dimensions of the welding partners and the process speed to industrial levels, we present USP welding with a galvoscanner and a common F‐theta lens. Differences between the well‐known breakdown regime and the filamentation regime are discussed and tensile measurements are shown.

Performance comparison between dual cantilevered and touch based hybridized triboelectric harvesters

The demand for energy harvesting technologies has been increasing over the years attributed to its significance to low power applications. One of the key problems associated with the vibration-based harvester is the fact that these harvesters generate low usable power while maximum peak power can only be attained when the device frequency matches the source frequency. In this study, triboelectric mechanism was investigated in combination with the piezoelectric mechanism in order to enhance the performance of the harvester. Triboelectric mechanism functions in a way that two dissimilar materials were placed in contact and then separated in order to generate surface charges and electric potential between them. Main design factors such as materials, surface area, structure, effective length, and etc. play a significant part in the enhancement of the performance. This study proposed two distinct designs of dual cantilevered structure and touch-based triboelectric energy harvester and evaluated the efficiency of the output between both structures. In addition, the effect of extension and surface area of triboelectric materials was investigated while the influence of these factors on the performance of the harvester was evaluated. The highest value of peak power obtained for dual cantilevered hybrid harvester was 650 µW across a load of 160 kΩ and frequency of 26 Hz. On the other hand, touch-based energy harvester produced an output peak power of 1220 µW across a load of 400 kΩ at 25 Hz. Achieving these power outputs may be able to power up electronics such as smartwatches, hearing aid and etc. Future studies on reliable low power applications to further advance the green power technology will be investigated.

Two-Phase Robust Target Localization in Ocean Sensor Networks Using Received Signal Strength Measurements.

Target localization plays a vital role in ocean sensor networks (OSNs), in which accurate position information is not only a critical need of ocean observation but a necessary condition for the implementation of ocean engineering. Compared with other range-based localization technologies in OSNs, the received signal strength (RSS)-based localization technique has attracted widespread attention due to its low cost and synchronization-free nature. However, maintaining relatively good accuracy in an environment as dynamic and complex as the ocean remains challenging. One of the most damaging factors that degrade the localization accuracy is the uncertainty in transmission power. Besides the equipment loss, the uncertain factors in the fickle ocean environment may result in a significant deviation between the standard rated transmission power and the usable transmission power. The difference between the rated and actual transmission power would lead to an extra error when it comes to the localization in OSNs. In this case, a method that can locate the target without needing prior knowledge of the transmission power is proposed. The method relies on a two-phase procedure in which the location information and the transmission power are jointly estimated. First, the original nonconvex localization problem is transformed into an alternating non-negativity-constrained least square framework with the unknown transmission power (UT-ANLS). Under this framework, a two-stage optimization method based on interior point method (IPM) and majorization-minimization tactic (MMT) is proposed to search for the optimal solution. In the first stage, the barrier function method is used to limit the optimization scope to find an approximate solution to the problem. However, it is infeasible to approach the constraint boundary due to its intrinsic error. Then, in the second stage, the original objective is converted into a surrogate function consisting of a convex quadratic and concave term. The solution obtained by IPM is considered the initial guess of MMT to jointly estimate both the location and transmission power in the iteration. In addition, in order to evaluate the performance of IPM-MM, the Cramer Rao lower bound (CRLB) is derived. Numerical simulation results demonstrate that IPM-MM achieves better performance than the others in different scenarios.

Design and optimisation of magnetically-tunable hybrid piezoelectric-triboelectric energy harvester

The demand for energy harvesting technologies has been increasing over the years that can be attributed to its significance to low power applications. One of the key problems associated with the available vibration-based harvester is the maximum peak power can only be achieved when the device frequency matches the source frequency to generate low usable power. Therefore, in this study, a magnetically-tunable hybrid piezoelectric-triboelectric energy harvester (MT-HPTEH) was designed and optimised. Four key design factors: mass placement, triboelectric surface area, extension length and magnetic stiffness were investigated and optimised. The voltage generation from piezoelectric and triboelectric mechanisms was determined individually to understand the effect of each design factor on the mechanisms. An output power of 659 µW at 180 kΩ at 44 Hz was obtained from the optimised MT-HPTEH with a theoretical–experimental discrepancy of less than 10%. The added magnetically-tunable feature enabled the harvester to work at the desired frequency range with an open circuit voltage between 7.800 and 20.314 V and a frequency range from 38 to 54 Hz. This MT-HPTEH can power at least six wireless sensor networks and can be used for low power applications such as RFID tags. Future work may include designing of energy-saving and sustainable harvester.

A highly birefringent bend-insensitive porous core PCF for endlessly single-mode operation in THz regime: an analysis with core porosity

We present an endlessly single-mode, bend-insensitive and highly birefringent photonic crystal fibre (PCF) for efficient wave transmission in the terahertz (THz) spectrum. To facilitate flat dispersion and high birefringence, a diamond-shaped porous core is introduced inside the Zeonex (background material)-based hexagonal porous cladding. Moreover, the dense geometrical arrangement of the regular hexagonal lattice in the cladding region holds maximum usable optical power inside the porous core. The major geometrical parameter of the proposed PCF such as core porosity has been optimized to improve the optical guiding parameters. The numerically investigated outcomes have shown an ultrahigh birefringence and numerical aperture of 0.0888 and 0.57, respectively. Apart from this, very low bending and material losses of $$3.01 \times 10^{ - 20}$$ cm−1 and 0.01451 cm−1 with flattened dispersion variation of ± 0.2463 ps/THz/cm have been achieved over the broad THz band (i.e. 0.8–1.3 THz). Additionally, our proposed PCF sustains endlessly single-mode operation with a very high core power fraction of 75.28%. With all these promising results, the proposed PCF would be a potential candidate for polarization preserving as well as for efficient broadband transmission applications in the THz regime.

Evaluation of Thermoelectric Properties of Doped β-Iron Disilicide Prepared by the Powder Metallurgy Technique

Thermoelectric generator (TEG) offers a potential application in harvesting waste-heat energy into usable electrical power. β-iron disilicide (β-FeSi2) thermoelectric is applicable in elevated temperature systems such as hydrogen plants, copper reverberatory furnace and copper refining furnace. In this work, high TE performance Mn doped p-type and Co doped n-type thermoelectric (TE) β-iron disilicide compacts were fabricated for TEG using powder metallurgy route. The effects of variation in type and quantity of dopants [p-type dopant: Mn: stoichiometry Fe1−xMnxSi2 (x = 0.04 − 0.12) or n-type dopant: Co: stoichiometry Fe1−yCoySi2 (y = 0.01 − 0.05)] on thermoelectric properties were studied. Significant improvement in ZT was observed compared to earlier research works for this material system. This result is a positive indication for the potential use of β-FeSi2 in the high temperature TEG. In this work, the working efficiency was also evaluated which was not mentioned in the earlier research works.

Testing Maximum Power Point Tracking Controller for PV System

Recently, the demand for renewable energy sources, in particular solar, has been increasing. This is due to declining demand for other fuels due to the poor reputation, waste of nuclear energy and limited fossil resources such as coal. The growing popularity of silicon significantly reduces the cost and increases the availability of solar energy. The main technique of increasing efficiency of the converter is to find maximum power point tracking (MPPT) that addressing problem of efficiency of power transfer from the solar cell depends on both the amount of sunlight falling on the solar panels and the electrical characteristics of the load. As the amount of sunlight varies, the load characteristic that gives the highest power transfer efficiency changes, so that the efficiency of the system is optimized when the load characteristic changes to keep the power transfer at highest efficiency. This load characteristic is called the maximum power point and MPPT is the process of finding this point and keeping the load characteristic there. Electrical circuits can be designed to present arbitrary loads to the photovoltaic cells and then convert the voltage, current, or frequency to suit other devices or systems, and MPPT solves the problem of choosing the best load to be presented to the cells in order to get the most usable power out.This article considers the construction of MPPT controller of solar panel, which must operate at up to 60W power of solar panel and up to 30V of output battery voltage. Given the structure of the system and the necessary operating parameters, for its construction it is necessary to take into account various circuit solutions for the power unit, as well as methods for finding the point of maximum power for the control circuit.The design and construction of the MPPT controller of the photovoltaic system and testing for different irradiation values is considered. Various circuit design solutions and algorithms for the operation of the MPPT controller were analyzed and a two-switch buck-boost circuit and a perturb and observe algorithm were selected. After making the system task is at general checking of possible operating in a given range of current and voltage, as well as the ability to respond to changes in current and voltage values and some external conditions that directly affect the work of a solar panel. The algorithm of work, formulas for emulation and an example of system work were given. The algorithm of work, formulas for emulation and an example of system work were given. The time diagrams of the control signals of the transistors at the time of switching from buck mode to boost mode are shown. A step-by-step description of the changes that occur in the system during the change of parameters and how the feedback stabilizes the operation of the device to maintain the maximum power of the system.After the developed experiment, the workability of the layout was checked and various variants of operation of the device for different lighting conditions were simulated. A conclusion was drawn on the potential for further development of the proposed solution. The circuit used operates at a given power and the proposed idea has the potential for further development and experimenting.

Multidisciplinary Design Optimization for a Solar-Powered Exploration Rover Considering the Restricted Power Requirement

The energy requirements of a solar-powered exploration rover constrain the mission duration, traversability, and tractive capability under the given limited usable power. Thus, exploration rover design, more specifically, rover wheel design (related to considerable energy consumption in driving), plays a significant role in the success of exploration missions. This paper describes the modeling of an operational environment and a multi-body dynamics (MBD) simulation tool based on wheel-terrain interaction model to predict the dynamic behavior on a digital elevation model (DEM) map. With these simulation environments, a multidisciplinary optimal wheel design methodology, integrating the MBD simulation tool and non-dominated sorting genetic algorithm-II (NSGA-II), is developed. Design parameters are chosen through sensitivity analysis. These multi-objective optimizations in dynamic states are conducted to obtain the optimal wheel dimension that meet the limited power condition with maximal tractive capability under the given operational environment. Furthermore, numerical and experimental verification using a single wheel testbed on lunar simulant are conducted to convincingly validate the derived optimization results. Finally, these results reveal that the proposed design methodology is an effective approach to deciding the best design parameter among a large variety of candidate design points considering the restricted power requirement.

Pyroelectric catalysis

Thermal energy derived from temperature fluctuation is one of the most clean natural energy sources in our living environment. Pyroelectric materials that feature for temperature oscillation dependent spontaneous polarization can generate usable electrical power and polarized charge carriers with a high energy conversion efficiency. Thus, pyroelectrics emerge as catalysts, which provide a promising approach to alleviating severe environmental contamination, energy crisis and biomedical issues. In this review, a comprehensive summary with first insight on the research progress of pyroelectric catalysis was provided. It starts with the introduction of some typical pyroelectric materials and pyroelectric effects. Then the fundamentals and mechanisms of pyroelectric catalysis were proposed. Highlighted are the pyroelectric catalytic applications, including disinfection and dynamic therapy, decomposition of pollutants and water splitting, and the strategies for enhancing pyroelectric catalytic efficiency put forward from diverse perspectives. Finally, the current challenges and future prospects in pyroelectric catalysis are discussed as a conclusion. This review provides a timely and comprehensive summary on pyroelectric catalysis. The typical materials, fundamentals, mechanisms and diverse applications of pyroelectric catalysis, including disinfection and dynamic therapy, decomposition of pollutants and water splitting, were demonstrated. The strategies for enhancing pyroelectric catalytic efficiency were summarized from diverse perspectives. • Some typical pyroelectric materials and pyroelectric effects were introduced. • The fundamentals and mechanisms of pyroelectric catalysis were proposed. • Diverse pyroelectric catalytic applications are highlighted. • Strategies for enhancing pyroelectric catalytic efficiency were proposed.

Dual Process Strategy to Increase the Usable Power for Laser-Milling

Dual Process Strategy to Increase the Usable Power for Laser-Milling

The Power and Efficiency Analyses of the Cylindrical Cavity Receiver on the Solar Stirling Engine

The technique of solar dish and Stirling engine combination is the most challenging and promising one. For the efficient conversion of the externally concentrated heat to the usable power, we studied the influences of the wall temperature, inclination angle, and open area ratio of the receiver on the Stirling engine power and efficiency. The theoretical analysis of the heat exchange element of the solar Stirling engine was performed, and the simulation model of the cavity absorber was built and analyzed. The temperature cloud and heat loss trends of the receiver under different wall temperatures, inclination angles, and opening ratios were illustrated. When the wall temperature of the absorber changes from 700 to 1000 K, the efficiency of the engine has increased by 8.8% from 21.34% to 30.11%. The higher the temperature, the higher the efficiency. As the inclination angle of the absorber increases from 0° to 60°, the efficiency of the engine is increased by 7.7% from 21.1% to 28.8%. With the increases of the aperture ratio, the engine output and efficiency reduced. The engine efficiency at the aperture ratio of 0.5 is 4% larger than that at the aperture ratio of 1.

High voltage generation from wastewater by microbial fuel cells equipped with a newly designed low voltage booster multiplier (LVBM)

Although microbial fuel cells (MFCs) can produce renewable energy from wastewater, the generated power is practically unusable. To extract usable power from an MFC fed with wastewater, we newly developed a low voltage booster multiplier (LVBM), which is composed of a self-oscillating LVB and multistage voltage multiplier circuits (VMCs). The low output MFC voltage (ca. 0.4 V) was successfully boosted up to 99 ± 2 V, which was the highest voltage that has been ever reported, without voltage reversal by connecting an LVB with 20-stage VMCs. Moreover, the boosted voltage (81 ± 1 V) was stably maintained for > 40 h even after disconnecting the LVBM from the MFC. The energy harvesting efficiency of LVBM was > 80% when an LVB with 4-stage VMCs was charged to 9.3 V. These results clearly suggest that the proposed LVBM system is an efficient and self-starting energy harvester and storage for low-power generating MFCs.

A Branch-and-Price-and-Cut Algorithm for the Cable-Routing Problem in Solar Power Plants

A solar power plant is a large-scale photovoltaic (PV) system designed to supply usable solar power to the electricity grid. Building a solar power plant needs consideration of arrangements of several important components, such as PV arrays, solar inverters, combiner boxes, cables, and other electrical accessories. The design of solar power plants is very complex because of various optimization parameters and design regulations. In this study, we address the cable-routing problem arising in the planning of large-scale solar power plants, which aims to determine the partition of the PV arrays, the location of combiner boxes, and cable routing such that the installation cost of the cables connecting the components is minimized. We formulate the problem as a mathematical programming problem, which can be viewed as a generalized capacitated minimum spanning tree (CMST) problem, and then devise a branch-and-price-and-cut (BPC) algorithm to solve it. The BPC algorithm uses two important valid inequalities, namely the capacity inequalities and the subset-row inequalities, to tighten the lower bounds. We also adopt several acceleration strategies to speed up the algorithm. Using real-world data sets, we show by numerical experiments that our BPC algorithm is superior to the typical manual-based planning approach used by many electric power planning companies. In addition, when solving the CMST problem with unitary demands, our algorithm is highly competitive compared with the best exact algorithm in the literature.

Ecological and economic evaluation of development technology of Kumuhsky deposit of thermal waters

An ecological and economic assessment of the Kumukh thermal water field development based on a binary geothermal power plant was carried out. To show the prospects and the possibility of increasing the energy efficiency of a binary geothermal power plant at different temperatures of the injected coolant. Using a specific thermal water field as an example, the primary circuit technological parameters of a geothermal power plant were optimized, and its energy efficiency was evaluated in subcritical and supercritical organic Rankine cycles. It is shown that optimization allows to significantly improve the efficiency of energy cycles in the field, and the utilization of low-potential energy of spent brines in heat pump plants allows saving substitute fossil fuels. The analysis shows that the creation of integrated technologies for the field high-potential mineralized geothermal resources’ development will significantly improve the region’s economic structure and environmental situation. The creation of a binary geothermal power station at the Kumukh thermal water field will allow obtaining relatively cheap, environmentally-friendly electric energy with a capacity of up to 15 MW, and 2-3 MW of usable thermal power in heat pump installations, with an annual output of 135 · 106 kW · h of electric energy (more than 350 million rubles/year) and the annual savings of replacement fossil fuel more than 4000 tif. in a year.

Radio Waveguide-Double Ratchet Rotors Work in Unison on a Surface to Convert Heat into Power.

Synchronizing thousands of 100% efficient rotors in a macrodevice for harvesting noise is unapprehended. Thermodynamically, realizing a thermal gradient at the atomic scale is critical. Harvesting free thermal energy or noise by resonance has a hidden clause; either externally activating a directed self-powered motion or constructing a nanoscale power supply. To accomplish this, we combined two rotor concepts, Brownian rotor, BR, and power stroke, PS, rotors available in living systems in two planes of a single molecule. Quantum tunneling images reveal how a radio-wave guided synchronization of PS-BR combination tweaks rotational dynamics of a rotor to bypass the necessity of temperature gradient (ΔT). Live imaging of thermal noise movement as electron density between a pair of molecular planes helped in optimizing the rotor design. The rotor's monolayer harvests heat from the liquid's Brownian noise and electromagnetic noise, together delivering a finite, usable power. The chip supplies the power if we wet the surface or shine electric noise.