Ought to batteries be thought of as energy sources or are they simply transitional energy-storage vessels? This isn’t a trick query: the reply depends upon how and the place they’re getting used in addition to semantics and an understanding of their position.

In case you are utilizing a battery alone to energy your system, gadget, or no matter, you possible regard it as a supply. However within the greater image, except you recharge or exchange that battery, it’s only a depleting reservoir for saved vitality. In different phrases, because the cliché goes, the place you stand on the matter depends upon the place you sit. (Word that I implicitly embrace supercapacitors on this dialogue; regardless that they use a really totally different energy-storage mechanism, they nonetheless characterize a chargeable, battery-like system.)

I used to be excited about this due to all the eye I see being given to batteries as endless energy sources, even on a bigger scale. For instance, there was a current analysis mission which mentioned a brand new type of battery. On this case, the mission “Micro-supercapacitive stone module for pure vitality storage” mentioned how researchers at Kookmin College and the Kumoh Nationwide Institute of Know-how (each in Korea) fabricated stone supplies into supercapacitors to operate as vitality storage programs (ESS) models which had been rugged sufficient for use for kitchen counters and so might be constructed into the home (Determine 1).

Determine 1 By fabricating a high-performance uneven microsupercapacitor (MSC) on a pure stone floor, researchers envision a scalable vitality storage wall relevant as a three-dimensional vitality station inside or exterior a whole-building interface. Supply: American Chemical Society

Okay, to date so good. However among the public-relations messaging related to this analysis went past that position, implying they’ve provide you with a novel approach to energy future good dwelling programs utilizing these stones that may flip counter tops and partitions into batteries. There have been headlines akin to “Future good houses might be powered with electronics constructed on stones” and a few reviews known as these supercapacitor arrays “energy provides” which they’re and they don’t seem to be, relying in your perspective.

Even when the energy-storage capability (watt-hours) of those supercapacitor counter tops was adequate to energy the home for an unspecified period of time, what’s the supply of vitality wanted to cost them: photo voltaic, wind, different? There’s a “one thing for nothing” facet to those tales which means that batteries are infinite vitality sources. But as we all know, with regards to vitality and energy sources, there are only a few free lunches.

I’ve the identical considerations with dialogue of hydrogen as various gasoline for gasoline cells. Sure, the quantity of accessible hydrogen is big, however getting it to be a gasoline doesn’t come straightforward. Whether or not you employ fundamental electrolysis of water or a extra superior course of, that extracted hydrogen continues to be a stored-energy useful resource. But many discussions about the advantages of hydrogen have the implication that it’s a main vitality supply moderately than a storage medium.

It will get much more complicated with the eye given to utilizing electrical automobiles and their batteries’ “energy sources” in what is known as vehicle-to-grid (with the snappy acronym V2G). In some ways this looks as if a fantastic concept: use all EV batteries to help a house and even the grid when the grid is down; even higher, when EVs are accumulating “additional” energy they received’t be needing instantly, they’ll ship that extra again to the grid (Determine 2).

Determine 2 In a vehicle-to-grid topology, the batteries within the automobile might be use as the premise for an vitality storage system (ESS) which may ship energy to the grid in addition to cost from the grid. Supply: Elsevier/Science Direct

Apart from this: if I step again and attempt to get an summary, this dialogue has some features of a perpetual-motion machine with vitality going back-and-forth as vehicles ship vitality to the grid and the grid charging the vehicles in a round relationship. Every get together within the association assumes the “different man” will present energy however that will not be a viable long-term plan. As well as, V2G additionally requires that every automobile be geared up with a bidirectional energy converter which provides to design complexity, thermal points, house necessities and, after all, price.

There’s little question it is smart in some instances to have all these automobiles willingly dump their treasured battery vitality onto the grid underneath the fitting situations, however I’m not seeing it occur typically, or on a large scale. It does appear considerably ironic or wishful that individuals would spend huge {dollars} for a automobile with larger-capacity battery and to realize larger driving vary, solely to then divert a few of that vitality to the nameless grid.

This isn’t to say that there is no such thing as a position for utilizing the batteries of a automobile as a supply of AC energy, unrelated to supporting the grid. The favored Ford F-150 with an integral Professional Energy Onboard system has a built-in generator and full energy panel that makes use of the truck’s engine as a generator when battery energy is getting low and so retains the household-style 120-V retailers within the mattress powered and helpful, Determine 3.

Determine 3 The Ford F-150 is obtainable with an entire battery-based ESS able to proving 120/240 VAC with automated charging of the battery pack from the principle engine as wanted. Supply: Ford Motor Firm

The engine kicks on and off as wanted to maintain the system powered; with the hybrid mannequin F-150, it offers as much as 7.2 kW of accessible energy for operating instruments, lights, and even home equipment. Nonetheless, utilizing it as a complicated generator for native jobs or energy throughout a blackout may be very totally different than utilizing it in V2G mode to help the grid.

You’ll be able to see some fascinating V2G views and predictions in lots of on-line sources together with a trio of current articles in IEEE Spectrum (see References). Word that V2G can also be getting appreciable consideration in non-technical media and websites however a lot of it’s merely mistaken on the technical information and confused or muddled on key points.

What’s your view on the viability of V2G as a broad-based strategy to utilizing automobile batteries to retailer extra energy generated from numerous sources akin to renewables, then sending this energy to the grid if wanted? Technically possible? Worthwhile? Going to occur on giant scale? An “tutorial” train however not way more?


  1. IEEE Spectrum, “Ford, Volkswagen, and GM Discover EV-Powered Homes”
  2. IEEE Spectrum, “What V2G Tells Us About EVs and the Grid”
  3. IEEE Spectrum, “This Dutch Metropolis Is Highway-Testing Car-to-Grid Tech”
  4. Journal of Digital Science and Know-how, “Technical investigation on V2G, S2V, and V2I for subsequent technology good metropolis planning”

Invoice Schweber is an EE who has written three textbooks, lots of of technical articles, opinion columns, and product options.

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