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Charge and discharge Batteries into grid?

Charge and discharge Batteries into grid?

Charge and discharge Batteries into grid?

(OP)
Does anyone have plans for building such a system? It will be used to demonstrate the effect of electric cars on the grid. They invision people just charging at night and using the cars batteries as a spinning resrve during the day. As I see it the crux will be building a synchronous inverter. Does anyone have plans for building one or should I tell them they have to spend $2000 for a small grid tie in inverter. Any input on the subject would be welcomed. Thanks.

RE: Charge and discharge Batteries into grid?

That's a non trivial,(potentially dangerous), exercise.  I'd go for the grid tie inverter.

Frankly I'd reach for the simulator.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Charge and discharge Batteries into grid?

The part about charging at night I can see (envision).  The part about using the car's batteries as spinning reserve during the day I can't see or don't understand.  If I charge my car at night and partially discharge it driving it to work (assuming I have enough charge to get back home and don't need a freshening charge while at work) how do they envision using my battery as spinning reserve?  If they have to call on the "spinning reserve" how do I get home?

Even if I had enough charge to 'donate' some back to the grid during the day, how do you ensure that I still have enough to get home (since the afternoon peak comes right before or about the time I want to depart the office) or have a little extra in case someone mentions dollar beers at some pub off my regular route?

rmw

RE: Charge and discharge Batteries into grid?

I think battery storage systems have been tried in the several MW range.

Question: Who, or is allowed to, plug in there car at work?
Would your employer be willing to pay for you to top off your car charge at work?

Yes they make small grid tie inverters as small as a few hundred watts.

Question: If you have a limited number of charge-discharges on a set of batteries, what would be your incentive to allow them to be used by the power company?

RE: Charge and discharge Batteries into grid?

(OP)
http://www.acpropulsion.com/reports/V2G%20Final%20Report%20R5.pdf  This website has a full study on how they will be used as spinning reserve.  The idea is that the people providing the plugins will be so well rewarded for providing spinning reserve that they will be able to allow people to charge their cars for free and still make money.  Most cars are idle 22+ hours a day and can be utilized in this way.  The study estimates that if 5% of cars in California were connected like this they could supply 10% of the peak demand. The cars use wireless communication to speak to the ISO every 4 seconds and are never fully discharged. Check it out this technology has many upsides.

RE: Charge and discharge Batteries into grid?

Heck, if there had been a large base of plug-in electric vehicles in the Pacific Northwest this spring they could have been charging overnight for less than free as the electric market went negative several nights.

RE: Charge and discharge Batteries into grid?

(OP)

" electric vehicles with bi-directional grid power capability are well-suited to providing regulation due to their ability to respond rapidly to power commands, and because the long term net energy requirement for regulation usually nets out to zero if the nominal generation level is set at zero. This means that the vehicle would be both sourcing and sinking power under real time commands from the ISO. Over an extended time period, the net total energy balances out to approximately zero. Because of this, a battery electric vehicle could perform regulation function indefinitely, without discharging the battery. The battery state of charge would be maintained at a level high-enough to afford the driver most of the available range, but not high enough to place a limit on the ability to sink power as required by the regulation AGC commands."

RE: Charge and discharge Batteries into grid?

I'd second Keith's suggestion of getting a COTS grid-tie inverter -- anything else would be really dangerous, especially if you do not have proper anti-islanding.

I think the idea itself has merit, although, there are lots of people that need to drive home during the afternoon peak, and presumably would want to charge up their car at that time (I guess that depends on capacity).

RE: Charge and discharge Batteries into grid?

(OP)
Maybe spinning reserve was bad nomenclature they would really be used as a regulation resource.

RE: Charge and discharge Batteries into grid?

Sounds to much utopia, what's the down side?

I think the negative power cost has to do with having to much wind and base load generation. Maybe they should be shutting down the highest cost units.

RE: Charge and discharge Batteries into grid?

In order for the idea to work on a large scale, lots of things have to happen that haven't yet.

Who gets paid for the electricity we extract from the battery? How do we pay you?  
The building owner, who provides the plug-in point can't because he would be selling electricity the car owner bought. That isn't polite.

So the car owner must get paid and we have to figure out how. Does each plug-in have a card reader so we can credit the card? Who pay for the reader? The building owner? Why would he do that?

Does the car have an identified owner, like those toll paying machines? That might work I guess, but a lot on infrastructure is needed.

Finally this seems more suited to plug in hybrids than straight EV. With a hybrid the buy back cost would have to be high enough to make it attractive to sell the electricity you already bought and drive home on gasoline, plus enough to make the charge/discharge cost attractive.

RE: Charge and discharge Batteries into grid?

Also I agree with those who say buy an inverter.

RE: Charge and discharge Batteries into grid?

(OP)
The cars would never be fully discharged.  They would maybe operate in the 70% to 90% range.  Because they are used for regulation they would be both sink and source.  The net power required for regulation is around zero, but because power plants must now stay on standby to provide this power it is very expensive.  Third pary aggregators would provide the service to IOUs or ISOs and could compensate car owners with things like free parking and free charging.  Simple software would tell the charging mechanism when the driver needs a full charge and could easily be updated via cell phone.  In the event you get off work early or have an unepected emergency the car would always have at least 70%.   

RE: Charge and discharge Batteries into grid?

As soon as electric cars become popular the government will have to figure out a way to tax them to death, how will that work?
In the North plug ins are already provided by lots of employers for freeze protection.
Does anyone have a number for KWH / Km (mile) at different speeds?
Roy

RE: Charge and discharge Batteries into grid?

The negative market this spring was due to too much water and not being able to throttle back the hydro units; probably little combustion source power in that mix but there would be whatever wind power was available.

RE: Charge and discharge Batteries into grid?

Quote:

As soon as electric cars become popular the government will have to figure out a way to tax them to death, how will that work?
Considering that highway maintenance funds are generally provided by the tax on gasoline, there will have to be a replacement tax.  Unless electric cars don't need highways.
 

RE: Charge and discharge Batteries into grid?

epepito,
I understand that the intention of the regulation would be to even out, never the less there is the real possibility that I would want to drive home immediately after a drain period and I would have to be compensated for any net drain. So all the payment issues would remain.

Also the text suggests it would net out over the long term not necessarily over the period I am parked.

Finally, with due respect I take the results that say the batteries won't be discharged with a grain of salt.

Regards Dave
 

RE: Charge and discharge Batteries into grid?

(OP)
Dave,
The software that controls how much and when your car is used for regulation resides inside the car.  You input these parameters.  Nothing could be done without you first allowing it through plugging your car in and opting in or out via the software. Are you worried that your power will be stolen? It seems a little ridiculus that an aggregator who relied on a large pool of cars would bother stealing from batteries, besides, the charge monitoring software and hardware are all onboard.  They make their money aggregating a large quantity of cars into a product that is useful to the ISOs and IOUs and communicating immediate need to the individual cars.  It would be counter productive for them to alienate car owners by stealing power.  Because they are dealing with large quantities weather or not your car is plugged in or if you decide to just let them use 20% of your battery capacity is irrelavent.   Take a look at the study I posted if you are interested.  And as I said no individual car would ever be drained more than say 30% percent of its total capacity. Compensation will be an issue because I'm sure a lot of people will be tying to get a piece of the pie, but right now the climate is such that green technologies are pretty well compensated and as I said earlier having power plants for regulation requires them to be up and running when not in use.  Keep in mind we are talking sources that can be activated in seconds not minutes or hours so compensation is much higher than scheduled generation. Many aggregators already exist that make money just by shedding load when asked to do so.

RE: Charge and discharge Batteries into grid?

epepito,
I am not worried about theft of my energy (or anything else, and I didn't mean to sound negative). I was simply trying be point out that some means of compensation would be necessary.

The point I was making is that fact that the regulation function should mean close to zero long term difference to my battery the system for monitoring and compensation had to be in place.

I suppose an aggregator could tempt me to sign up regardless of how much energy he resold (provided it was less than 30% of my capacity). Even then though wouldn't he need to prove he provided the capacity to his customers?

RE: Charge and discharge Batteries into grid?

It occured to me that a facility with large power demands could use this as a means of peak shaving, and set the charge control on various parking stalls so that whatever gets put into the car at low demand periods can be taken out again at high peak demand periods.  Obviously there would need to be compensation, lots of thought given to metering and control etc.

In any case, I think that the idea has some merit, in fact if you did have a huge amount of battery storage, it would make sense to try and use it to smooth out demand.

I think a worthwhile question is whether or not there will ever be enough cars with deep cycle batteries on the road for this to ever work.

RE: Charge and discharge Batteries into grid?

(OP)
Companies like BPL already do this kind of work in Demand Respose.  They use wireless networks and CTs on individual circuits to monitor available and actual power shedding.  I think all the technology exists its just start up that is hard because the network is not in place and there are too few cars available in the market.  Also I belive IOUs don't really have an incentive to be efficient because they generally just take a cut off the top.  In the long run higher energy costs yield bigger profits for the IOUs, so why would the want 3rd parties to come and make the system more efficient and take another piece of the pie.  

RE: Charge and discharge Batteries into grid?

Maybe read up on utility ratemaking and regulation

RE: Charge and discharge Batteries into grid?

(OP)
Are you saying utilities don't make more money when energy prices are higher, don't pass on all infrastructure costs and don't pay for power they use?  They have energy reduction programs, but I believe those generaly mandated to them.  Depending on what part of the country you are in getting utilities give up any part of the profit can be a real chore.  They are beholden to the stockholder first and foremost not the customer.

RE: Charge and discharge Batteries into grid?

Maybe read up on utility ratemaking and regulation.
Then you wouldn't be asking these questions.

But as a help to you, at high load times utilities use high fuel cost plants because they are cheapest to build and have short run times.

Prices to consumers are fixed by the regulator.

Simple math says utilities don't make more on consumer sales at peak.
 

RE: Charge and discharge Batteries into grid?

(OP)
This would also be useful for companies using a TOU rate on their own fleet of eletric vehicles.  Peak shaving is a prime concern for maintaining reliability and maximum efficiency of existing infrastructure.

RE: Charge and discharge Batteries into grid?

Lots of good reasons to do it. Just start up headaches.
Those are common.

RE: Charge and discharge Batteries into grid?

(OP)
Simple math says utilities figure out what it costs to provide the energy and then figure out how much to charge for it.  Unless you're saying that utilities pay for the extra costs of peak demand out of their own pocket I don't really see your point.  I realize that even after deregulation they can't just charge whatever they feel like, but I certainly feel that the extra costs incuured with meeting peak demand, frequency regulation, etc. are passed on to the customer.  Furthermore I believe it is also true that the more money they bring in the larger their profits will be maybe not as a percent but overall.  These are privately owned companies, that is their job.  I'm not trying to put them down, I'm just saying it is a fact of life.

RE: Charge and discharge Batteries into grid?

(OP)
Hey Keith,
Where do I pick up one of those simulators?

RE: Charge and discharge Batteries into grid?

As a matter of fact, not all utilities make a profit. There are many not for profit utilities, that have demand managment programs, and the result is about the same. Not that many people want the utility company playing with there hotwater heater.

For this scheme to work there seems to be a lot of things that have to happen first, and each has a price tag. Who is going to pay that price? Us the tax payers?

It would seem that a much better option is to enact time of use rates and let the consumers decide the peak shaving issue.

RE: Charge and discharge Batteries into grid?

Hi epepito.

I was referring to something like MathCad or Mathworks.

I don't see how one car set up to do this would help in any kind of test.  What you propose can absolutely be done. There is no technical issue with it.  I see your testing as being similar to testing to see if eggs can be hard boiled.  Of course they can!  Just like "can you draw from batteries and put energy back onto the grid?"  Of course you can!

The question is a statistical question.  The solution would be to model the average expected electric vehicles in this scheme then do simulations based on grid needs verses fleets of willing cars out there.  For this you want a math tool.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Charge and discharge Batteries into grid?

Another question for you, Keith. What are the typical losses associated with charging and then discharging a battery for energy storage. Are we going to pay a dollar in losses to make a dime on energy storage?

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Charge and discharge Batteries into grid?

(OP)
Keith,
It's not a testing kind of lab. It's for demonstration.  We have many people coming through from FERC people to members of congress.  We use these demonstrations as a means to promote policy change etc. at many different levels.
P.S.  I was refering to shareholder owned utilities not municiple utilities, but all that is really kind of off topic.  I didn't mean to upset anyone.  Charging and discharging in small amounts appeared to have little effect on AC Propulsions batteries.  Although they did not do long term testing, suprisingly their batteries actually increased in capacity after running their tests.  I believe it is full drains and recharges that severly affect battery life.  Lead acid batteries are more prone to this, but probably won't be used when and if these vehicles go into production.  Constant topping off of the batteries may even extend battery life when contrasted with batteries that are nearly completely drained and then recharged at the end of the day.  Of course all that will depend on the type of battery technology that ends up being used.

RE: Charge and discharge Batteries into grid?

This is just what the utility industry needs..... Make the system even more complicated so we have to hire more business people and lawyers to get their piece of the pie. I come to work every day in the industry and still don't know how the lights stay on. I guess it's Ohm's Law or maybe the Electricity Gods, I'm not quite sure.

RE: Charge and discharge Batteries into grid?

I see epepito.  That makes sense.

waross; Answer: Not real good..  Lead acid is about 60~65% for charging. ++   But as epepito points out, new battery chemistries are getting better at this.


++ This is a big part of why solar homes want to be grid tied so any solar generated electricity doesn't go thru a charging stage.

Keith Cress
kcress - http://www.flaminsystems.com

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