An official website of the United States government
Abstract Solar power is mostly influenced by solar irradiation, weather conditions, solar array mismatches and partial shading conditions. Therefore, before installing solar arrays, it is necessary to simulate and determine the possible power generated. Maximum power point tracking is needed in order to make sure that, at any time, the maximum power will be extracted from the photovoltaic system. However, maximum power point tracking is not a suitable solution for mismatches and partial shading conditions. To overcome the drawbacks of maximum power point tracking due to mismatches and shadows, distributed maximum power point tracking is utilized in this paper. The solar farm can be distributed in different ways, including one DC–DC converter per group of modules or per module. In this paper, distributed maximum power point tracking per module is implemented, which has the highest efficiency. This technology is applied to electric vehicles (EVs) that can be charged with a Level 3 charging station in <1 hour. However, the problem is that charging an EV in <1 hour puts a lot of stress on the power grid, and there is not always enough peak power reserve in the existing power grid to charge EVs at that rate. Therefore, a Level 3 (fast DC) EV charging station using a solar farm by implementing distributed maximum power point tracking is utilized to address this issue. Finally, the simulation result is reported using MATLAB®, LTSPICE and the System Advisor Model. Simulation results show that the proposed 1-MW solar system will provide 5 MWh of power each day, which is enough to fully charge ~120 EVs each day. Additionally, the use of the proposed photovoltaic system benefits the environment by removing a huge amount of greenhouse gases and hazardous pollutants. For example, instead of supplying EVs with power from coal-fired power plants, 1989 pounds of CO2 will be eliminated from the air per hour.
more »
« less
3D-Printed Lattice Batteries
Lightweight batteries are highly consequential to a wide range of Department of Defense (DoD) applications, including the use of unmanned aerial systems (UAS), wearable devices, and light combat vehicles. Additionally, the use of increasingly sophisticated equipment has caused DoD power requirements on the battlefield to rise substantially in re- cent years (see Figure 1). For example, a typical Army platoon in Afghanistan in 2001 required just 2.07 kilowatts per hour to power their devices. That requirement now stands at 31.35 kilowatts per hour [1–3]. Technologies that enable the production of higher-capacity batteries at the same weight (or lower) will bolster warfighter mobility and readiness.
more »
« less
- Award ID(s):
- 1747608
- PAR ID:
- 10200018
- Date Published:
- Journal Name:
- HDIAC journal
- Volume:
- 5
- Issue:
- 4
- ISSN:
- 2578-0840
- Page Range / eLocation ID:
- 11
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
New technologies for future electronics such as personal healthcare devices and foldable smartphones require emerging developments in flexible energy storage devices as power sources. Besides the energy and power densities of energy devices, more attention should be paid to safety, reliability, and compatibility within highly integrated systems because they are almost in 24-hour real-time operation close to the human body. Thereupon, all-solid-state energy devices become the most promising candidates to meet these requirements. In this mini-review, the most recent research progress in all-solid-state flexible supercapacitors and batteries will be covered. The main focus of this mini-review is to summarize new materials development for all-solid-state flexible energy devices. The potential issues and perspectives regarding all-solid-state flexible energy device technologies will be highlighted.more » « less
-
Recent advancements in semiconductor technologies have stimulated the growth of ultra-low power wearable devices. However, these devices often pose critical constraints in usability and functionality because of the on-device battery as the primary power source [1]. For example, periodic charging of wearable devices hampers the continuous monitoring of users' fitness or health conditions [2], and batteries and charging equipment have been identified as one of the most rapidly growing electronic waste streams [3]. To counteract the above-mentioned complications associated with the management of on-device batteries, wireless power transmission technologies capable of charging wearable devices in a completely unobtrusive and seamless manner have become an emerging topic of research over the past decade [4]. Researchers have instrumented daily objects or the surrounding environment with equipment that can wirelessly transfer energy from a variety of sources, such as Radio Frequency (RF) signals, laser, and electromagnetic fields [5]. However, these solutions require large and costly infrastructure and/or need to transmit a significant amount of power to support reasonable power harvesting at the wearable devices, which conflict with the vision of ubiquitously available and scalable charging support.more » « less
-
Lithium-ion batteries almost exclusively power today’s electric vehicles (EVs). Cutting battery costs is crucial to the promotion of EVs. This paper aims to develop potential solutions to lower the cost and improve battery performance by investigating its design variables: positive electrode porosity and thickness. The open-access lithium-ion battery design and cost model (BatPac) from the Argonne National Laboratory of the United States Department of Energy, has been used for the analyses. Six pouch battery systems with different positive materials are compared in this study (LMO, LFP, NMC 532/LMO, NMC 622, NMC 811, and NCA). Despite their higher positive active material price, nickel-rich batteries (NMC 622, NMC 811, and NCA) present a cheaper total pack cost per kilowatt-hour than other batteries. The higher thickness and lower porosity can reduce the battery cost, enhance the specific energy, lower the battery mass but increase the performance instability. The reliability of the results in this study is proven by comparing estimated and actual commercial EV battery parameters. In addition to the positive electrode thickness and porosity, six other factors that affect the battery's cost and performance have been discussed. They include energy storage, negative electrode porosity, separator thickness and porosity, and negative and positive current collector thickness.more » « less
-
Abstract Mesenchymal stem cells (MSCs) are multipotent cells that can replicate and differentiate to different lineages of mesenchymal tissues, potentiating their use in regenerative medicine. Our previous work and other studies have indicated that mild heat shock enhances osteogenesis. However, the influence of pro-inflammatory cytokines on osteogenic differentiation during mildly elevated temperature conditions remains to be fully explored. In this study, human MSCs (hMSCs) were cultured with Tumor Necrosis Factor-alpha (TNF-a), an important mediator of the acute phase response, and Interleukin-6 (IL-6) which plays a role in damaging chronic inflammation, then heat shocked at 39ºC in varying frequencies - 1 hour per week (low), 1 hour every other day (mild), and 1 hour intervals three times per day every other day (high). DNA data showed that periodic mild heating inhibited suppression of cell growth caused by cytokines and induced maximal proliferation of hMSCs while high heating had the opposite effect. Quantitative osteogenesis assays show significantly higher levels of alkaline phosphatase activity and calcium precipitation in osteogenic cultures following mild heating compared to low heating or non-heated controls. These results demonstrate that periodic mild hyperthermia may be used to facilitate bone regeneration using hMSCs, and therefore may influence the design of heat-based therapies in vivo.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- The DOI is not currently available.
