# Energy Storage Brainstorm



## abudabit (Sep 18, 2008)

Lithium is fine for now, it just needs to be cheaper.


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## joseph3354 (Apr 2, 2008)

abudabit said:


> Lithium is fine for now, it just needs to be cheaper.


have to agree with that! 

prices are dropping rapidly,hopefully they will continue to drop.


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## gmijackso (Sep 30, 2008)

I don't think it matters how slowly you compress the air. The air is going to increase in temperature no matter what, the only difference is that when you compress it slowly, there is more time for this increase in temperature to be dissipated to the air around it, therefore it seems as though it's not increasing temperature.

Every expanding gas cools, there's no way around it. Conversely, every compression of gas increases temperature, also no way around it. Every change in temperature is a loss of energy. 

Compressing air may seem a "thing of the future" but it's not. Compressing air is effectively what the steam engine is doing. The only difference is that instead of taking atmospheric pressure, and compressing it, then releasing it as you do with conventional compressed air, steam production takes atmospheric pressure, adds moisture, and heats it to cause expansion creating an increase in pressure to do work. Very similar, only in the inverse of each other.

Compressed air is a very inefficient way of doing things. The only thing it really has going for it is the cost and portability. Air is free, compressing it costs no more than the electricity used to run the compressor, and once compressed, is quite portable (though the danger increases exponentially). 

Before anybody starts posting links, yes I know about the various compressed air vehicles. I didn't say it didn't work, I just said it wasn't efficient, and just because it's cheaper than gasoline doesn't make it efficient.


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## Ioku (Sep 27, 2007)

abudabit said:


> Lithium is fine for now, it just needs to be cheaper.


Well lithium is good but still no were near petrols power to weight ratio even with the crapy efficiency of the ice your average small car that gets around 30 mpg can go 300 on 10 gallons of petrol that only weighs like 50 pounds maybe more not really sure. But to get the same range out of lithium in the same car you would need over 1000 pounds of lithiums. And you wouldn't be able to recharge in 5 10 minutes, I think when we start to see battery's that can get you the same range for as petrol for the same weight and can recharge in 5 10 minutes (likely only possible at a commercial charging station) then you will start to see all electric EV's really take off, but until then I think they will mostly be hybrids.


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## Qer (May 7, 2008)

Ioku said:


> Well lithium is good but still no were near petrols power to weight ratio even with the crapy efficiency of the ice your average small car that gets around 30 mpg can go 300 on 10 gallons of petrol that only weighs like 50 pounds maybe more not really sure. But to get the same range out of lithium in the same car you would need over 1000 pounds of lithiums. And you wouldn't be able to recharge in 5 10 minutes, I think when we start to see battery's that can get you the same range for as petrol for the same weight and can recharge in 5 10 minutes (likely only possible at a commercial charging station) then you will start to see all electric EV's really take off, but until then I think they will mostly be hybrids.


You're doing the same, imo, erroneous assumption than most people: This is a car, ergo it should behave as all cars I've been used to since 1947 (or whatever).

I think what HAS to be done is to keep working on peoples awareness that most of the mileage a car goes in it's life time are short trips to work and back, to the store etc. You don't NEED that unlimited mileage (unlimited as in being able to refuel), stop staring at that limitation as an obstacle.

The average bloke can survive with a range that can be achieved with lead, most of them that can't get around on lead can survive fine with lithium. For that extremely small part of the population that still can't get around on a daily basis EV's aren't their salvation, they need a hybrid car. It's technically too complicated and too expensive to try to construct an EV that behaves like an ICE when it comes to range, the only thing you can achieve with that is wasting tons of money and contribute to the prejudice of the EV's. If we're going to wait for the battery technology to catch up with ICE-range I bet that both you and I are going to be dead by long before that happens.

Personally I think that it's not the technology that fails, it's peoples opinion and prejudices. Everyone "knows" that an EV can't go more than to the mailbox and back and only in 25 miles/hour, therefore noone is interested. With the hybrids this opinion has started to shift and the plug-in hybrids that are coming more and more people will start to drive EV's without really realizing it. Give it a decade or two and people will start to realize that they're paying money for service on an ICE that's practically never used.

The only thing that's needed is the EV's to get into mass production, then the lower running cost will do the work to convince people. Why would people even consider Hyundai Atos and other toy cars if it weren't for that they're cheap...? After all, it's a pretty rotten car...


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## Technologic (Jul 20, 2008)

Qer said:


> Why would people even consider Hyundai Atos and other toy cars if it weren't for that they're cheap...? After all, it's a pretty rotten car...


 
Ironically hyundai is a vastly more reliable brand (statistical problems with the car reported each year) than any american car company or mercedes/BMW (who rank almost dead last) on the most reliable car company charts.


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## abudabit (Sep 18, 2008)

I do agree that refuelling instead of recharging is much more convenient, I mean imagine taking a road trip in an electric. Perhaps fuel cells will be the future of electric. Or perhaps some other medium, perhaps batteries where you can trade the fluid in them with the 'gas station'. A 2 way pump which extracts the spent fluid in the battery and injects charged fluid. Meanwhile all day the gas station is recharging the spent fluid it extracted. 

Unfortunately, anytime you are talking about an infrastructure change you are dealing with standardization, large investment costs, and national consesus. So for now, besides hybrids, electrics are relegated commuter cars.


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## AlexZ (Aug 26, 2008)

Yes I agree that if we can charge at home over night, then we dont need the range of a gas car because our daily commute is smaller, and probably getting smaller... BUT.. how much energy do we lose by lugging around heavy battries which such low energy density, even li-ion is extremly low compared to gasoline. Is that not an issue?


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## ragee (May 25, 2008)

Not really,
The issue is lugging around big wads of cash to keep buying gas to help finance terrorist both domestic fat cats and foreign oil tin gods. IMHO 

I use my ev for short everyday trips and use my wonderful reliable Hyundai for the long ones and only buy a tank of gas once a month or less.

ragee


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## Qer (May 7, 2008)

Technologic said:


> Ironically hyundai is a vastly more reliable brand (statistical problems with the car reported each year) than any american car company or mercedes/BMW (who rank almost dead last) on the most reliable car company charts.


True. However, they still suck. It's not a car, it's a shoe box. 



abudabit said:


> So for now, besides hybrids, electrics are relegated commuter cars.


And I think that's the future; todays car's won't be replaced with the future car, it will be replaced with the future car*S*, each tailored for a certain task, each superior for their own tasks compared with the old, inefficient, all-round ICE's.



AlexZ said:


> BUT.. how much energy do we lose by lugging around heavy battries which such low energy density, even li-ion is extremly low compared to gasoline. Is that not an issue?


Yes, but to me that's a smaller issue than the ICE's ROTTEN performance. Sure, gasoline contains a lot of energy, on the other hand an ICE takes more than 3 times the energy to do the same task. THAT'S an issue in my book, if nothing else so because the fumes only kills thousands of people each year.


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## 1clue (Jul 21, 2008)

Technologic said:


> Ironically hyundai is a vastly more reliable brand (statistical problems with the car reported each year) than any american car company or mercedes/BMW (who rank almost dead last) on the most reliable car company charts.




This is skewed by the very market that buys them. To a Hyundai owner, a "problem" is when you can no longer drive the car. To a BMW or Mercedes owner, an oil change is "having work done." On really nice examples, finding a place where the upholstery is not perfect is a problem, and they take it in for that. If they have to take it to the dealer or an authorized service center, then it's "having work done." It does not matter whether it's maintenance or a flaw.

I struggled with the apparent disparity for years before I figured that out. All these Honda (and other cars) owners who insist they've never touched the engine for 150,000 miles, when you know very well they've had the regular maintenance because the dealer does it for you at first.


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## AlexZ (Aug 26, 2008)

ragee said:


> Not really,
> The issue is lugging around big wads of cash to keep buying gas to help finance terrorist both domestic fat cats and foreign oil tin gods. IMHO
> 
> I use my ev for short everyday trips and use my wonderful reliable Hyundai for the long ones and only buy a tank of gas once a month or less.
> ...


I see your point, but it falls under a differnt subject.


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## ragee (May 25, 2008)

Im sorry but I couldnt help myself.


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## ga2500ev (Apr 20, 2008)

Use liquid nitrogen instead of compressed air:

http://www.aa.washington.edu/aerp/CRYOCAR/CryoCar.htm

A LN2/CNG/Electric tribrid would be just about perfect.

ga2500ev


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## gmijackso (Sep 30, 2008)

What next... Liquid Nitrogen is over $6.00 a gallon most places, add to that the danger of a tank rupture, and you have to wonder why bother?

Why don't we all just put sails on our roofs? Almost as practical and it's be a lot more fun watching people tack their cars against the wind to get where they want to go.


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## ga2500ev (Apr 20, 2008)

gmijackso said:


> What next... Liquid Nitrogen is over $6.00 a gallon most places,


Reference? The following is from the Physics Factbook:


> Two factors can influence the price of liquid nitrogen. The price of liquid nitrogen varies according to how far away from the condensing plant you are and the different packaging and handling of the material. The farther you are from the condensing plant, the higher the cost of the liquid nitrogen. In addition, when delivered in Dewar flasks, liquid nitrogen costs about $2 per gallon but when delivered in bulk storage tanks, it costs about $0.50 per gallon. Nonetheless, *the atmosphere is about 78 percent nitrogen so liquid nitrogen can be manufactured anywhere and will still be relatively cheap.*


http://hypertextbook.com/facts/2007/KarenFan.shtml

The emphasis is mine. All you need to manufacture liquid nitrogen anywhere is a condenser and electricity. Presuming that a LN2 infrastructure is needed it should be pretty easy to set up where it is needed.



> add to that the danger of a tank rupture, and you have to wonder why bother?


My post was in answer to compressed air. I think I'd much rather take my chances with a tank pressure of 60 PSI as opposed to the compressed air tank at 3000-4500 PSI. A ruptured LN2 tank will leak and be cold (OK very very cold!). A compressed air tank may explode releasing a whole lot of explosive force. LN2 can't explode.



> Why don't we all just put sails on our roofs? Almost as practical and it's be a lot more fun watching people tack their cars against the wind to get where they want to go.


Laugh if you like. The OP correctly pointed out that the energy density and recharging time of batteries makes them impractical for wide scale deployment. EVs are going to need to be put in a hybrid system with an energy carrier that is carbon neutral, renewable, has decent energy density, and can be refilled quickly. LN2 by itself fills virtually all of those needs. Couple it with heating with CNG, which is fairly plentiful, low emissions (because the CN2 is completely burned instead of exploded), and available in the US, and you get a system that virtually matches the energy profile of gas.

ga2500ev


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## gmijackso (Sep 30, 2008)

ga2500ev said:


> Reference?


While I didn't do a great deal of research, I googled liquid nitrogen price. One must also consider the demand factor. If the demand for liquid nitrogen suddenly went up, so would price.



ga2500ev said:


> All you need to manufacture liquid nitrogen anywhere is a condenser and electricity. Presuming that a LN2 infrastructure is needed it should be pretty easy to set up where it is needed.


The infrastructure would indeed lower the price again. However, saying that all you need "is a condenser and electricity" is kinda like saying to produce gasoline all you need is oil and a refinery. Or to produce electricity all you need is fuel and a generator. No matter what you're still liquefying a gas and that takes a LOT of energy. In every change of state of matter energy is lost.



ga2500ev said:


> My post was in answer to compressed air. I think I'd much rather take my chances with a tank pressure of 60 PSI as opposed to the compressed air tank at 3000-4500 PSI. A ruptured LN2 tank will leak and be cold (OK very very cold!). A compressed air tank may explode releasing a whole lot of explosive force. LN2 can't explode.


The pressure is much safer, I'll agree. But a nitrogen leak even a small one would displace all of the oxygen in your enclosed vehicle given enough time. Before that happened, you'd suffer from nitrogen poisoning and end up in a small painful pile as you're experiencing the "Benz" aka decompression sickness.

My point being that compressing and decompressing any fluid is a wasteful practice. Where are you getting the energy to do the compression? You have to think further down the pipe to where ALL of the energy required is coming from. The electric system as it stands in the United States has a difficult time supporting the load now. Now we're going to suggest taking the millions of megawatts of energy being used by ICE and load it onto the grid as well? To worsen it, we're not even going to do it efficiently? Rather than actually storing and using the electricity the grid is providing, we want to transform it to mechanical with a loss, compress a fluid with a loss, expand a fluid with a loss, and convert to mechanical with a loss?

In every thread I post trying to come up with ideas to increase efficiency, I get responses like "that only gains 5% to 10%". Well, if you're not concerned about efficiency, why do it in the first place? You can be inefficient with much better range, and no work burning gasoline. 

Sorry for my slight rant, but I often feel the point is being missed, or maybe I'm the one missing the point.


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## HDS (Aug 11, 2008)

I agree that in truth, our commutes are much shorter than the total range afforded by a gas tank on an ice. If we all had electric cars, we would be plugging them in every night. We don't refill our gas tanks every day. So attempting to match the range of an ice is not a goal that I think should be on our radar screens. Regarding abudabit's thought of "refueling" on the road, here is my thought. We don't really have to worry about establishing a recharging infrastructure, it is already in place. Everyone has electricity. I would hope to see EV's progress to the point where it is viable for Dunkin Donuts, Longhorns, Applebees, TGIF's, etc., to have special parking spots for EV's. Each one having a plug that you can use to hook up while you are in their restaurants. If I have an EV and the Longhorn offers a hookup while the neighboring Outback does not, I'm going to Longhorn's. Perhaps there can be tax breaks offered for providing this power.

I think Ragee is right on about the cost of fuel. If you have a 50 mile commute to work each day, and your ice gets 10 mpg (for easy numbers) you will use 10 gallons of gas each day to get to work. If gas is $3.50 per gallon, thats $35 per day, $175 per week, or $787.50 per month. That's practically a mortgage payment!! 

The Tesla Roadstar has 1200 pounds of Lithiums and recharges for about $3 per night. The trouble is that the vehicle costs about $150,000. If I could afford to pay that much for a car, I wouldn't worry about the $3.50 per gallon of gas! I think that for an EV to successfully grab a large chunk of the market from ice's it has meet the following standard.
1) If I had the above commute, I would be seriously looking at an EV that cost $40K or less. I think that the bank loan on the EV would be hundreds of dollars less than I was spending on gasoline now. The price has got to make sense financially.
2)At $25K or less for an EV, a lot of people would bee looking at it for an every day vehicle (not just for the commute to work). At $15K there would be one in every garage.
3) It has to be fun to drive. You will always have an audience of those concerned for the environment that would look at EV's but if it is fun to drive, everyone will want one.


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## ga2500ev (Apr 20, 2008)

gmijackso said:


> While I didn't do a great deal of research, I googled liquid nitrogen price. One must also consider the demand factor. If the demand for liquid nitrogen suddenly went up, so would price.


LN2 is a byproduct of liquid oxygen production. The price isn't going to change.



> The infrastructure would indeed lower the price again. However, saying that all you need "is a condenser and electricity" is kinda like saying to produce gasoline all you need is oil and a refinery. Or to produce electricity all you need is fuel and a generator. No matter what you're still liquefying a gas and that takes a LOT of energy. In every change of state of matter energy is lost.


We are not discussing efficiency at this point. BTW according to this wikipedia entry:

http://en.wikipedia.org/wiki/Liquid_nitrogen_economy

The efficiency is 50%. Considering that gas only has 25% efficiency when exploded, that's not necessarily the biggest issue.



> The pressure is much safer, I'll agree. But a nitrogen leak even a small one would displace all of the oxygen in your enclosed vehicle given enough time. Before that happened, you'd suffer from nitrogen poisoning and end up in a small painful pile as you're experiencing the "Benz" aka decompression sickness.
> 
> My point being that compressing and decompressing any fluid is a wasteful practice. Where are you getting the energy to do the compression? You have to think further down the pipe to where ALL of the energy required is coming from. The electric system as it stands in the United States has a difficult time supporting the load now. Now we're going to suggest taking the millions of megawatts of energy being used by ICE and load it onto the grid as well? To worsen it, we're not even going to do it efficiently? Rather than actually storing and using the electricity the grid is providing, we want to transform it to mechanical with a loss, compress a fluid with a loss, expand a fluid with a loss, and convert to mechanical with a loss?
> 
> In every thread I post trying to come up with ideas to increase efficiency, I get responses like "that only gains 5% to 10%". Well, if you're not concerned about efficiency, why do it in the first place? You can be inefficient with much better range, and no work burning gasoline.


I will answer the above. I gave a list of issues that need to be addressed by the next energy economy:

renewable
decent energy density
fast refilling
carbon neutral

Now note I am not proposing to only have LN2. Everything always starts with a plug in electric. But your range and refilling are limited. So you have to have a secondary energy system to get beyond the range of batteries.

LN2 can meet the list above.



> Sorry for my slight rant, but I often feel the point is being missed, or maybe I'm the one missing the point.


The point that you have to consider is that whatever replaces gasoline is going to have to have comparable range and refillibility. And you can't get that with just batteries.

ga2500ev


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## gmijackso (Sep 30, 2008)

ga2500ev said:


> The efficiency is 50%. Considering that gas only has 25% efficiency when exploded, that's not necessarily the biggest issue.


I think you're mixing your numbers there. LN2 PRODUCTION is about 50% efficient. Gasoline is about 25% efficient in it's current use in ICE. You're comparing production efficiency to use efficiency, they're not the same measure, and who knows exactly how efficient you can be in converting the LN2 to mechanical energy once you get it compressed and liquified. But you're already starting at a very low efficiency factor. Even if you were to somehow magically obtain a 100% efficient method of using LN2 to propel a vehicle, it's still only 50% efficient overall.


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## saab96 (Mar 19, 2008)

ga2500ev said:


> The point that you have to consider is that whatever replaces gasoline is going to have to have comparable range and refillibility. And you can't get that with just batteries.


Oustide of EESTOR, it's not going to happen. People are going to have to lower their expectations. They have to decide what's more important, range, or economy. You can't have both at the same time. The best compromise is a plugin so you can maintain the economy in everyday driving and make a calculated decision to spend money on road trips filling the gas tank. 

Ultimately EVs will be limited both by battery capacity and the rate of recharge. Even if we had EESTOR or altairnanos, you'd have difficulty finding a charging environment with enough amps to fill it in the same time it takes to fill a tank with gas.


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