A Compound Analogical Design for Low Cost Solar Panel Systems

Author(s):  
Joseph N. Goodman ◽  
Jeannette Yen ◽  
Russell Gentry ◽  
Kathryn M. Nagel ◽  
Guillermo J. Amador

In support of the Department of Energy Sunshot initiative target of $1.25 per watt photovoltaics systems for commercial applications, whole system designs were pursued using the analogical design methodology, an essential step in the bio inspired design approach. A functional decomposition of solar panel systems was conducted, and then key functions critical to system integrity and cost reduction were identified. Three sources of bio-inspiration were mainly used: hierarchical structures as a common design dimension exploited in natural systems, and leaves’ ability to maintain position through changes in shape and angle of attack when triggered by wind flow, and limpet shells’ reduction of hydrodynamic forces by way of natural geometrical features. The design team developed concepts with varying degrees of abstraction then attempted to reconcile them with other functional requirements. Variants that descended from the leaf concept were generally found to be biophilic and offer aesthetic value; however, presented shortcomings in electrical design and installation procedure (Kellert 2008). Alternatively, concepts inspired by hierarchical structures and limpet shells were found to have greater variability, enabling reconciliation with other functional requirements, resulting in a complete system solution capable of meeting the cost reduction objective. From the analysis of these design variants, we may conclude that transferring solution principles directly from nature is best done when there is small set of functional requirements that must be fulfilled and value in a biophilic design. However, in cases of significant system complexity, abstracted lessons from nature may be found to be more flexible and easily reconciled with multiple requirements.

Author(s):  
Olufunmilola Atilola ◽  
Joseph Goodman ◽  
Kathryn Nagel ◽  
Julie Linsey

Biologically inspired design is the process of using biological systems as analogues to develop innovative solutions for engineering problems. This paper describes an effective and successful implementation of problem-driven biologically inspired design in a real-world problem. In support of the Department of Energy SunShot Initiative, a national collaborative effort to make solar energy cost-competitive with other forms of electricity by the end of the decade, solar panel designs were carried out by engineering and architectural design teams. Solar Photovoltaic (PV) systems were developed using analogical design, and more specifically, bio-inspired design. Some systems were also designed using non-biological analogues. Functional decompositions were employed as the first step in the design process, as a way to identify the key functions essential to the system’s reliability and cost effectiveness. Six key functions were identified. Analysis of the final designs by the teams showed that the solar panel system designs using biologically inspired analogues were more effective in meeting the six key functions identified during functional decomposition. Employing a combination of divergent and convergent design thinking is also discussed as a way for effective biologically inspired design. The top three designs selected for prototyping were biologically inspired and exceeded the project goal of reducing the installation and labor costs of solar PV systems by 50%.


Author(s):  
Zhengwang Xu ◽  
Wei Mei ◽  
Jiaqi Yu ◽  
Jiarui Zhang ◽  
Yuchun Yi ◽  
...  

As being restricted by factors such as cost, efficiency and size, the development of high-power solar LED street light controller is faced with plenty of difficulties. In case that a structure of two independent DC/DC is applied as the main circuit, it has to face problems such as large size and high cost; in case of applying the bidirectional BUCK/BOOST circuit, it requires change-over switches to control the solar panel and LED light. As being restricted by withstanding voltage, on-resistance and cost, a PMOS device cannot be used as the change-over switch of solar panel and LED light. However, when being used as a change-over switch, an NMOS device must apply the low-side mode under which the negative ends of the mentioned three parts are cut off. In the condition of applying the low-side mode, a differential circuit must be used to detect the voltage of the solar panel. Furthermore, in order to make sure batteries can still be regularly charged after wearing out in daylight, the controller must be supplied with power through a dual power supply circuit that can obtain power from both the solar panel and the battery. The demander has a requirement on extremely low standby power consumption of the product, and thus it is necessary to minimize the circuit that is live while working in standby mode. Methods: The bidirectional BUCK/BOOST circuit structure is applied to the main circuit to realize a higher change-over efficiency while giving considerations to both cost and size. The NMOS device, model IRFB4410ZPBF, with a price of about three yuan, is used as the switching device, and the low-side mode is applied, that is the switches inserted in between negative end of the solar panel or LED light and that of the DC/DC circuit. The low-cost rail-to-rail operational amplifier LM358 is used to form a differential amplification circuit for detecting the voltage of the solar panel. A XL1509-12E1 chip that only costs 0.88 yuan/pc is selected as the main change-over chip for the power supply, which has realized the highly-efficient and low-cost change-over of the power supply. A dual power supply circuit and a step-down protective circuit are designed for the XL1509-12E1 change-over chip. By comparing solar panel voltage with battery voltage, the solar panel booting circuit is realized. Only when solar panel voltage is higher than battery voltage, does the system program start to power it up for running, so that the outage of most of the circuits of the system under standby mode does not consume energy. Furthermore, the solar panel voltage detecting circuit, the solar panel booting circuit and several return difference functions are corrected during system debugging. Results: The circuit board of the entire controller features small size, low cost and high efficiency. It measures about 100*62*18mm in size, costs about 60 yuan, and the charge/discharge change-over efficiency reaches up to over 95%. The controller has many functions: it is capable of operating within a large scope, in which, solar panel voltage is subject to 15~50V, LED light voltage is subject to 15~60V, battery voltage is subject to 10~35V and battery-end charge/discharge current is 10A; it is capable of adapting to monocrystalline silicon/multicrystalline silicon/thin-film and many other kinds of solar panels, as well as lithium/lead-acid and many other kinds of batteries; it is capable of detecting the conversion of day and night, automatically controlling charging and discharging and automatically making adaptive adjustment according to seasonal variations; the current to be consumed during standby will be maintained below 3mA, and thus the power consumption is extremely low. Conclusion: By selecting the bidirectional BUCK/BOOST circuit structure, applying low-side mode for switching of solar panel and LED light, using a differential circuit to detect solar panel voltage, using a low-cost DC/DC chip to realize power supply change-over, designing a dual power supply circuit, introducing solar panel booting circuit and other hardware design, as well as MPPT algorithm, state recognition and control, return difference control and other software design, a solar LED street light control product featuring small size, low cost, high efficiency and multiple functions is successfully developed.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 785
Author(s):  
Chow Shing Shin ◽  
Yu Chia Chang

Lattice structures are superior to stochastic foams in mechanical properties and are finding increasing applications. Their properties can be tailored in a wide range through adjusting the design and dimensions of the unit cell, changing the constituent materials as well as forming into hierarchical structures. In order to achieve more levels of hierarchy, the dimensions of the fundamental lattice have to be small enough. Although lattice size of several microns can be fabricated using the two-photon polymerization technique, sophisticated and costly equipment is required. To balance cost and performance, a low-cost high resolution micro-stereolithographic system has been developed in this work based on a commercial digital light processing (DLP) projector. Unit cell lengths as small as 100 μm have been successfully fabricated. Decreasing the unit cell size from 150 to 100 μm increased the compressive stiffness by 26%. Different pretreatments to facilitate the electroless plating of nickel on the lattice structure have been attempted. A pretreatment of dip coating in a graphene suspension is the most successful and increased the strength and stiffness by 5.3 and 3.6 times, respectively. Even a very light and incomplete nickel plating in the interior has increase the structural stiffness and strength by more than twofold.


2021 ◽  
Vol 2 (2) ◽  
pp. 325-334
Author(s):  
Neda Javadi ◽  
Hamed Khodadadi Tirkolaei ◽  
Nasser Hamdan ◽  
Edward Kavazanjian

The stability (longevity of activity) of three crude urease extracts was evaluated in a laboratory study as part of an effort to reduce the cost of urease for applications that do not require high purity enzyme. A low-cost, stable source of urease will greatly facilitate engineering applications of urease such as biocementation of soil. Inexpensive crude extracts of urease have been shown to be effective at hydrolyzing urea for carbonate precipitation. However, some studies have suggested that the activity of a crude extract may decrease with time, limiting the potential for its mass production for commercial applications. The stability of crude urease extracts shown to be effective for biocementation was studied. The crude extracts were obtained from jack beans via a simple extraction process, stored at room temperature and at 4 ℃, and periodically tested to evaluate their stability. To facilitate storage and transportation of the extracted enzyme, the longevity of the enzyme following freeze drying (lyophilization) to reduce the crude extract to a powder and subsequent re-hydration into an aqueous solution was evaluated. In an attempt to improve the shelf life of the lyophilized extract, dextran and sucrose were added during lyophilization. The stability of purified commercial urease following rehydration was also investigated. Results of the laboratory tests showed that the lyophilized crude extract maintained its activity during storage more effectively than either the crude extract solution or the rehydrated commercial urease. While incorporating 2% dextran (w/v) prior to lyophilization of the crude extract increased the overall enzymatic activity, it did not enhance the stability of the urease during storage.


2007 ◽  
Vol 129 (4) ◽  
pp. 1020-1027 ◽  
Author(s):  
Xuehua Zhu ◽  
Luis San Andrés

Micro-turbomachinery demands gas bearings to ensure compactness, light weight, and extreme temperature operation. Gas bearings with large stiffness and damping, and preferably of low cost, will enable successful commercial applications. Presently, tests conducted on a small rotor supported on flexure pivot hydrostatic pad gas bearings (FPTPBs) demonstrate stable rotordynamic responses up to 100,000rpm (limit of the drive motor). Test rotor responses show the feed pressure raises the system critical speed (increase in bearing direct stiffness) while the viscous damping ratio decreases. Predictions correlate favorably with experimentally identified (synchronous) direct stiffness bearing force coefficients. Identified experimental gas bearing synchronous damping coefficients are 50% or less of the predicted magnitudes, though remaining relatively constant as the rotor speed increases. Tests without feed pressure show the rotor becomes unstable at ∼81krpm with a whirl frequency ratio of 20%. FPTPBs are mechanically complex and more expensive than cylindrical plain bearings. However, their enhanced stability characteristics and predictable rotordynamic performance makes them desirable for the envisioned oil-free applications in high speed micro-turbomachinery.


Author(s):  
Jianfeng Zhang ◽  
Bin Wei ◽  
Lin Wang ◽  
Xuyong Yang

Metal halide perovskite light-emitting diodes (PeLEDs) have emerged as one of the most promising candidates for next-generation high-resolution displays, due to their wide color gamut, high color purity and low-cost...


PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e76968 ◽  
Author(s):  
Manuela Buonanno ◽  
Gerhard Randers-Pehrson ◽  
Alan W. Bigelow ◽  
Sheetal Trivedi ◽  
Franklin D. Lowy ◽  
...  

2020 ◽  
Vol 24 (1) ◽  
pp. 25-38
Author(s):  
Damanpreet Kaur ◽  
Kajal Dhawan ◽  
Prasad Rasane ◽  
Jyoti Singh ◽  
Sawinder Kaur ◽  
...  

AbstractRice bean (Vigna umbellata) is a legume that belongs to Vigna genus. Native to Indo-Chinese region, it is considered to be an ‘under-utilized’ or ‘orphan’ crop. Rice bean is known to possess high nutritional potential and antioxidant activity. But the use of rice bean supplementation in routine diet is limited despite its high nutritional profile due to the presence of non-nutritional factors. Thus, various pre-treatments like soaking, germination, oven roasting, sand roasting, boiling and pressure cooking at different time and temperature were carried out to reduce the anti-nutritional content of rice bean and to study its effect on antioxidant activity and phytochemical content. All the pre-treatments were able to significantly reduce the anti-nutrient content in rice bean, but germination showed the maximum reduction. Also germinated rice bean showed the maximum antioxidant potential and maximum content of total phenols, total flavonoids, vitamin C and carotenoids. Rice bean has been underutilized so far, owing to its antinutrient content and low popularity. This experiment attempted to use low cost processing to reduce the content of antinutrients and track the antioxidant content in rice bean. The concluded processing could be adopted for commercial applications for dietary supplementation.


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