In this work, an overview of the different types of batteries used for large-scale electricity storage is carried out. In particular, the current operational large-scale battery energy storage systems around the world with their applications are identified and a comparison between the different types of batteries, as well as with other types of large-scale energy storage systems, is presented. The analysis has shown that the largest battery energy storage systems use sodium–sulfur batteries, whereas the flow batteries and especially the vanadium redox flow batteries are used for smaller battery energy storage systems. The battery electricity storage systems are mainly used as ancillary services or for supporting the large scale solar and wind integration in the existing power system, by providing grid stabilization, frequency regulation and wind and solar energy smoothing.

A comparative overview of large-scale battery systems for electricity storage

Rising energy costs, losses in the present-day electricity grid, risks from nuclear power generation, and global environmental changes are motivating a transformation of the conventional ways of generating electricity. Globally, there is a desire to rely more on renewable energy resources (RERs) for electricity generation. RERs reduce greenhouse gas emissions and may have economic benefits, e.g., through applying demand side management with dynamic pricing so as to shift loads from fossil fuel-based generators to RERs. The electricity grid is presently evolving toward an intelligent grid, the so-called smart grid (SG). One of the major goals of the future SG is to move toward 100% electricity generation from RERs, i.e., toward a 100% renewable grid. However, the disparate, intermittent, and typically widely geographically distributed nature of RERs complicates the integration of RERs into the SG. Moreover, individual RERs have generally lower capacity than conventional fossil fuel-based plants, and these RERs are based on a wide spectrum of different technologies. In this article, we give an overview of recent efforts that aim to integrate RERs into the SG. We outline the integration of RERs into the SG along with their supporting communication networks. We also discuss ongoing projects that seek to integrate RERs into the SG around the globe. Finally, we outline future research directions on integrating RERs into the SG.

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Integrating Renewable Energy Resources Into the Smart Grid: Recent Developments in Information and Communication Technologies

Three-dimensional (3D) graphene-based composites have drawn increasing attention for energy applications due to their unique structures and properties. By combining the merits of 3D graphene (3DG), e.g., a porous and interconnected network, a high electrical conductivity, a large accessible surface area, and excellent mechanical strength and thermal stability, with the high chemical/electrochemical activities of active materials, 3DG-based composites show great promise as high-performance electrode materials in various energy devices. This article reviews recent progress in 3DG-based composites and their applications in energy storage/conversion devices, i.e., supercapacitors, lithium-ion batteries, dye-sensitized solar cells, and fuel cells.

/pdf/three-dimensional-graphene-based-composites-for-energy-4z77ydtw6g.pdf

Three-dimensional graphene-based composites for energy applications

As a consequence of rapidly increased CO 2 emissions, humanity is facing global warming. Electricity generation accounts for almost half of the emission; besides, conventional electrical production based on fossil fuel is becoming more and more expensive. One approach to significantly slow down global warming is to drive our society away from the current fossil fuel fiesta and use only renewable power such as solar and wind energy. Another approach is to improve the management of energy production, transmission, and distribution. Part of the latter solution is on the supply side, where one possible solution is to develop continent-wide smart power grids and energy storage systems. However, an equally important part of the solution is on the demand side, where technologies and applications that can work with this type of unpredictable energy consumption are becoming necessary. The smart power grid with new sources of data, fast growth of information, and proactive management requires new strategy for business and operational management. In this paper we discuss how Cloud computing model can be used for developing Smart Grid solutions. The Cloud computing model is based on the delivery of computing as a service, whereby storage, software and information are provided to computers and other devices as a commodity over the Internet. The advantages of Cloud computing – reduced costs, increased storage, on-demand performance, and better flexibility – have motivated many companies in recent years to move their IT operations to the cloud; the same advantages can be used to achieve the most important future goals of a large-scale Smart Grid, such as energy savings, two-way communication, and demand resource management.

Smart power grid and cloud computing

Legged locomotion on flowing ground (e.g., granular media) is unlike locomotion on hard ground because feet experience both solid- and fluid-like forces during surface penetration. Recent bioinspired legged robots display speed relative to body size on hard ground comparable with high-performing organisms like cockroaches but suffer significant performance loss on flowing materials like sand. In laboratory experiments, we study the performance (speed) of a small (2.3 kg) 6-legged robot, SandBot, as it runs on a bed of granular media (1-mm poppy seeds). For an alternating tripod gait on the granular bed, standard gait control parameters achieve speeds at best 2 orders of magnitude smaller than the 2 body lengths/s (≈60 cm/s) for motion on hard ground. However, empirical adjustment of these control parameters away from the hard ground settings restores good performance, yielding top speeds of 30 cm/s. Robot speed depends sensitively on the packing fraction φ and the limb frequency ω, and a dramatic transition from rotary walking to slow swimming occurs when φ becomes small enough and/or ω large enough. We propose a kinematic model of the rotary walking mode based on generic features of penetration and slip of a curved limb in granular media. The model captures the dependence of robot speed on limb frequency and the transition between walking and swimming modes but highlights the need for a deeper understanding of the physics of granular media.

/pdf/sensitive-dependence-of-the-motion-of-a-legged-robot-on-1eybfvs8l0.pdf

Sensitive dependence of the motion of a legged robot on granular media

Suppose you had a dog whose personality fluctuated with the weather. On cool, crisp mornings, he?s a champ, fetching, rolling over, and shaking hands at your slightest command. But as the sun climbs higher and the day warms up, he becomes less and less responsive, and you have to ply him with doggy treats to get him to obey. And during heat waves? Forget about it?he barely plays dead unless you double or triple his kibble ration.

http://ieeexplore.ieee.org/iel5/6/4734037/04734316.pdf

Quantum leap

The Danish island of Bornholm, a quiet farming and fishing community of 42,000 in the Baltic Sea, will soon be home to one of the world's smartest smart grids. Through the four-year, €21 million (US $28 million) EcoGrid project, about 2000 households there will be connected to an islandspanning network that will enable homeowners to cut back their electricity usage at times of peak demand and sell that unused wattage back to the grid at market rates. Managing all of these thousands of discrete energy trades, as well as Bornholm's other power resources- including 36 megawatts of wind power, a 16-MW biomass plant, and a new fleet of electric cars-will be a central control system that behaves very much like a traditional power generator. Only this generator will be created entirely through software-a virtual power plant.

Virtual power plants, real power

Sometime this quar ter, a shovel will sink into the dry desert soil of a Mexicali industrial park, breaking ground for the construction of an unprecedented energystorage facility. Once completed, its batteries will be able to feed a full gigawatt into the grid for 4 to 6 hours.

A battery as big as the grid

Supplying electricity used to be so simple: some big coal plants, a few gigawatts of nuclear, maybe a hydroelectric dam for good measure- all of them capable of churning out a steady supply of watts. These days, more solar and wind energy means the electricity supply is often unpredictable and the power grid far more challenging to operate. A new project at a refrigerated warehouse in Switzerland could help meet that challenge.

http://ieeexplore.ieee.org/iel7/6/6521004/06521018.pdf

Swiss warehouse helps buffer the grid

Lithium-ion batteries are everywhere: You see them in gadgets, vehicles, robots, and power-grid storage. Worldwide production now stands at about 160 gigawatt-hours per year. The revolutionary technology earned three of its lead developers the Nobel Prize in Chemistry in 2019.

Jean Kumagai

Papers

Quantum leap

Virtual power plants, real power

A battery as big as the grid

Swiss warehouse helps buffer the grid

The return of the lithium-metal battery