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?
Frankly I'd reach for the simulator.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Charge and discharge Batteries into grid?
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?
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?
RE: Charge and discharge Batteries into grid?
RE: Charge and discharge Batteries into grid?
" 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 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?
RE: Charge and discharge Batteries into grid?
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?
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?
RE: Charge and discharge Batteries into grid?
RE: Charge and discharge Batteries into grid?
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?
RE: Charge and discharge Batteries into grid?
RE: Charge and discharge Batteries into grid?
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?
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?
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?
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?
RE: Charge and discharge Batteries into grid?
RE: Charge and discharge Batteries into grid?
RE: Charge and discharge Batteries into grid?
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?
RE: Charge and discharge Batteries into grid?
Those are common.
RE: Charge and discharge Batteries into grid?
RE: Charge and discharge Batteries into grid?
Where do I pick up one of those simulators?
RE: Charge and discharge Batteries into grid?
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?
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?
Bill
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"Why not the best?"
Jimmy Carter
RE: Charge and discharge Batteries into grid?
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?
RE: Charge and discharge Batteries into grid?
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