Due the elimination of the ion-exchange membrane I think the life of battery will be more as compared with the Lithium-ion batteries, but again the life will be limited because of the electochemical reactions at the electrodes. The article is not discussing about the life of the battery which is an important parameter in comparison of batteries.
The researchers primary purpose in eliminating the ion-exchange membrane, was to extend the lifetime of flow batteries, which they now claim to have achieved. However, long-term tests have yet to be performed on real membrane-less flow batteries to determine just how long they'll last.
Yes you are right, and from the architecture of the battery as explained it seems that this batteries will be surely have more life time as compared to the batteries we are using today. But will have to wait for the actual results for the exact figures.
In the early 80's my company demonstrated a very similar flow battery system, including building a 5MW system first installed in a Detroit Edison substation for initial testing, and then moved to the EPRI test facility in New Jersey. Frankly, you wouldn't believe the conversion and energy storage efficiencies we recorded for the systems. (Neither did some of our opponents and naysayers, but that's another story.)
This system used a flow cell incorporating both solid and porous graphite plates rather than a membrane. The big advantage was that the battery components didn't wear out, only occasionally requiring draining and replacing the electrolyte. Graphite, plastic, and fiberglass were the major structural components. Darned cheap!
This battery used a Zinc-Chlorine chemistry (ZnCl2) rather than bromine. Now before anyone panics over "chlorine", remember that bromine has some pretty nasty effects as well, and is potentially even more dangerous and difficult to contain. While you probably wouldn't want to drink it, the electrolyte was more like a weak chlorine-bleach solution, and wasn't going to hurt you if you spilled it on yourself.
Our primary addition to the technology of the ZnCl2 battery (First built in the 1800's) was our chlorine storage technique, so there was little chance of a massive and dangerous leak even with a major failure.
The system was designed for utility load-leveling applications, but would be perfect for wind-farms or large solar-array installations. In the case of wind-farms, the battery modules and associated equipment could easily be fit into some of the towers.
So essentially, this group has just "reinvented the wheel", using a chemistry that we considered to be more expensive and dangerous, but with the same mechanical components.
@Rob.B - you write very much in the past tense - what happened to this? If it's as good as you say (and I don't doubt you) then this technology should be all over the place (and you should be a rich man!)?
What happened to the technology? Internal company politics, and Roger Smith coming to power at GM, one of our project partners for the electric vehicle applications we were demonstrating for the batteries. (200 Miles per charge @ 45-50 mph, 5-hour recharge, battery never wearing out or losing range...)
If you look up Gulf & Western and Energy Development Associates (Not the new company by the same name.), you can find some of the history, along with a "pack of lies" and miss-representations. While the technology really wasn't suitable for consumer vehicles, it was fine for fleet or truck use, and the charging system I'd built was "plug-and-play", not requiring expert technicians as some have said. The stationary utility load-leveling battery application was great!
When Martin Davis took over at G&W, he wanted nothing to do with technology or manufacturing, focusing only on the entertainment industry, closing or selling off everything else. Roger Smith killed GM's EV programs. Roger told me, years later in a personal conversation, that the only reason he'd brought back electric vehicles later on was that he wanted to "leave a positive legacy."
As for being a rich man, maybe if GM would decide to pay me for the basic design I "gave" them during a job interview in 2005 for another vehicle they did decide to build... and didn't get quite right, but it's fairly close. I really have to learn to stop "giving it away." ;-)
Yes there are many ways to store Big Energy--my favorite is compressing the air in unground caves during demand lulls, then bleeding it off to generate electricity during demand peaks.
Smaller versions are possible--since their protype is small enough to handhold--but these researchers had the primary goal of meeting the $100 per kilowatt mandated by the DoE, which is the break-even point for grid-scale deployment.
do not confuse cost of storage with cost of generation. $100/kwh is a capital cost which is spread over its lifetime. What is not mentioned in the article is the cost of maintaining such a battery and any losses associated with charging/discharging.
Thanks for clarifying that $100/kwh is a capital cost. Regarding losses associated with charging/discharging and maintenance costs those are things to be explored and tuned during the optimization stage of development, which the researchers are beginning now.
I had heard that there are serious efficiency issues with compressed air, as you compress it there is a large amount of heat given off that is effectively energy loss. Air turbines aren't too bad in efficiency but piston engines aren't great. I still think water is a good storage medium because it doesn't compress during pumping so you only have the pumping losses and storage losses aren't too bad depending on the exposed surface to volume ratio of the storage and the ambient temperature.
Maybe pump it up-hill at night when demand is low (and energy is available for pumping) and flow it back thru the turbines during daytime peak demand. BTW Niagara Falls will soon have more generation capacity due to a "big-dig" to increase flow!
I'm not exactly sure of the position of power generation at Niagara with respect to the falls, but the actual location of the falls is receeding upstream at an amazing rate which just makes me wonder how soon it will have to be moved. Increasing water flow will increase errosion.
Regarding storage by pumping water uphill, here is Nate Lewis' comment (from MRS Bulletin, Oct. 2007): "...for every gallon of gasoline that we use, storing that same amount of energy in pumped water requires moving uphill by 100 m more than 50,000 gallons of water!"
I think the large-scale analysis is that this is modestly cost-effective (surprisingly efficient despite this huge volume) if the dam is already there, but not exactly a scaleable solution. The same is almost certainly true of compressing air in caves, only even worse.
This report sounds encouraging in principle; it would seem to me to come down to the details of engineering practicality. There is also a company in the U.K. (Isentropic) whose system stores energy in hot rocks, basically; a heat pump moves the energy from one to the other. "In principle" the efficiency is quite good; it all comes down to the practice.
Tech: Is exactly what ocurred in 1970 at Intel with me. In fact, I actually worked for the company for four months before filling out a job application!
They did not give me a chance to call my Mom or return the family car until off time the day of my interview. I was dressed in my IBM suit, when I was working at the PDP-8 computer all day, the other guy in the cubical thought I was the DEC service guy. When I returned the next day in casual cloths he said "Who the heck are you?"
Wayne Pickette Intel employee 243, 1970-75. I was never given a time card, they simply paid me for 40 hours work a week no matter how many hours I worked.
It sounds great: a solution to a real problem. However, that corrosion issue is a sticky one, and I wonder how it's handled. Bromine is nasty stuff, and hydrobromic acid is no better. On the other hand, energetic solutions require energetic mechansims, so... we'll see, right?
Optimization is the next step for the development team, which is optimistic because of the success they have had so far with the accuracy of their software simulator. Using it they hope to achieve the $100/kwh mark, but didn't project how many years that might take--I would guess two or three.
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