V2G for power regulation

[DarkStar]

I guess the big reason I don't "get" V2G is that our utility provider ends up selling a lot of its power outside of the region due to the surplus of "renewable energy" they generate. Their biggest problem is that they can't find enough customers at night to provide power to.

 

[raylev]

V2G would be great; but you can run a large house (V2H) for a couple of days from the 25kWH stored in EV batteries. The ultimate goal would be swappable battery packs, which could be used for both home and EV. BetterPlace has been working on this model for a few years now, and reportedly has taxis in Japan swapping batteries right now!

 

[jstack6]

As I mentioned ACPropulsion.com already has a working system. It is real and being tested in Delaware at the university of Delaware.
It pays for the utility, user and environment.

http://v2g-101.com/

Take a test ride with the Leonard J. Beck the V2G-101 author in the eBox! A gentleman with ‘Auto Green Blog’ videotaped a demo ride I provided during a Plug-in Hybrid Conference held in Washington, D.C., in September 2007: http://www.youtube.com/watch?v=ztP2pCI39sI

http://www.acpropulsion.com/products-v2g.html

 

[LakeLeaf]

V2G would be great; but you can run a large house (V2H) for a couple of days from the 25kWH stored in EV batteries. The ultimate goal would be swappable battery packs, which could be used for both home and EV. BetterPlace has been working on this model for a few years now, and reportedly has taxis in Japan swapping batteries right now!

In theory, yes. There is enough power in a fully charged Leaf pack to run the average house for about a month or so. Of course the Leaf doesn't support V2G, but as the battery packs get 5x to 10x the capacity of the Leaf and electric vehicles start to make a double digit percentage of the 240 million cars in the US, you can see just how much power is sitting in storage and V2G starts to become an attractive thing to think about.

 

[DaveEV]

There is enough power in a fully charged Leaf pack to run the average house for about a month or so.

Uh, far from it. If the Leaf used as much power in one full charge as a typical house did on one whole month, the grid would have some serious issues with even one EV in a neighborhood!

Depending on where you are, the Leaf will store about the same as one day's worth of electricity to a half days's worth of electricity. For example, houses in CA typically use about 500 kWh/month or 20 kWh/day, compared to high usage areas which use about 1000 kWh/month or 40 kWh/day. Of course, depending on your typical usage patterns, YMMV.

 

[walterbays]

http://www.economist.com/blogs/babbage/2011/05/electric_cars

What the power company would be paying for is not so much the electricity itself as the availability of that electricity at zero notice. At the moment, peaks in demand have to be sated by firing up expensive rapid-response generators, such as gas turbines ... owners would actually be paid a tariff related to when and for how long their cars were available for the power company to tap. In Delaware, this amounts to about 30 cents an hour. Add in a fixed fee payable just for being part of the system and Dr Kempton and Dr Pearre think an income of $4,000 a year per car might be possible. That is a sum far greater than the $225 that Nissan, for instance, thinks will be the average annual cost of the electricity needed to power one of its Leafs.

 

[DaveEV]

Interesting article about how AES is proposing a 400 MW battery storage system to the Long Island Power Authority with 1.2 MWH of storage (ability to push 400 MW for 4 hours). This is about 10x bigger than any existing grid-connected battery system now in place.

http://green.blogs.nytimes.com/2011/05/18/can-batteries-replace-power-generators/?partner=rss&emc=rss

While not V2G - the same concepts apply. I don't think we'll see any substantial V2G integration in the next 5-10 years at the soonest. Bigger opportunity will be 2nd use for old batteries - companies like AES will buy the old 80% of original capacity LEAF packs and use them for this grid regulation.

But let's say that V2G works - and you have a 20 kWh battery pack that is about 90% efficient for a charge discharge cycle (meaning you charge it with 10 kWh and you get 9 kWh out) and you're looking to buy cheap and sell at peak rates.

Assume typical California retail rates of 15c / kWh off-peak and 30c / kWh peak. Essentially this means that for every full charge (20 kWh = $3.00 cost to charge) you can sell 18 kWh for $5.40 or a profit of $2.40 - 13.5c profit for each kWh.

How many kWh do you need to get out of the battery at that rate to break even? Or make a profit? 1000 cycles would get you $2400 - if a LEAF battery pack is reported to cost about $10,000 you need to get at least 74 MWh out of the pack or 3700 full cycles - will it make it?

Some simplistic calculations - but it's pretty clear that at current battery prices and getting paid about 13.5c / kWh you feed back into the grid that you wouldn't want to your LEAF battery pack for V2G unless only used for frequency regulation (feeding/drawing from the grid at modest rates for a few kWh here and there) while the battery pack is sitting near the middle of it's charge to avoid unnecessary battery wear. And then - let's say you can do this for about 4 kWh or a profit of 50c/day / ~$180/year. Is this profit worth the additional expense of designing and maintaining a V2G system across thousands of vehicles?

 

[raylev]

I think the V2G concept is similar to the BetterPlace "battery subscription" wherein BP gets to manage theEVs that are plugged into the grid and will try to wheel" power back to the gird during peak times. This may sound better if electricity was allowed to be bought and sold in real time, as was done for a time here in California during the energy restructuring experiment. I was monitoring real-time prices and saw a kWH sell for as little as $0.00 from 2 - 3 am some nights, and as much as $75.00 (yep) during the peak times of the rotating blackout periods. Thank goodness electricity became re-regulated, and those Enron traders moved into financial trading where they not do as much harm to the country as they did to California. ;-)

I still think there is potential for V2H, but just for emergency backup power. Although having the EV battery pack double as a solar photovoltaic storage system seems interesting. If managed right, one could go off both the utility and gasoline grids, but it would be quite a balancing act.

 

[walterbays]

Essentially this means that for every full charge (20 kWh = $3.00 cost to charge) you can sell 18 kWh for $5.40 or a profit of $2.40 - 13.5c profit for each kWh.

A key point of the article was that it wasn't so much the electricity the utilities were paying so much for, as the possibility to deliver that electricity on a moment's notice. Thus they don't have to build so many expensive natural gas turbine plants, and don't have to keep so many of them idling burning fuel to be ready to instantly deliver power when demand peaks. Instead they could draw power from thousands of EVs for a short time (a few minutes?), just long enough to spin up some other less expensive reserve generation capacity.

 

[Randy]

I'm all about new ideas and ways of doing things, but I'm not at all excited right now about the idea of V2G. My very expensive Leaf battery has only so many charging cycles available. I want to use those cycles to charge the car and DRIVE it, not use the juice for the house or grid...

Yes, the price for batteries will eventually come down, but will it ever make economic sense? I don't want to ever go out to the garage ready to drive somewhere and find the battery depleted to the point where I can't drive where I need to go....

So I'd need a lot of additional facts / data before I would be interested in V2G....

 

[walterbays]

So I'd need a lot of additional facts / data before I would be interested in V2G....

We in the US will likely have lots of real world experience to examine before deciding whether US utilities and US drivers are interested in V2G. E.g., Denmark's experiment with V2G which they hope will enable them to increase the proportion of electricity generation from wind power from the current 20% to 40%, using EV batteries to buffer variable wind power. http://www.allcarselectric.com/blog/1021647_denmark-embarks-on-wind-vehicle-to-grid-experiment

The Economist article sounded like the utility would pay you for the ability to draw power for a short time without notice. They might use it the same way they pay businesses to shed load in power emergencies. What if the utility pulled 3.3kW from your car for just 30 minutes while they fired up a coal or natural gas plant? Losing 1.65 kWh a few times a year doesn't sound bad. Or what if the university's estimate is right and they'd pay you a few thousand dollars a year to share your battery. Even if it wears out faster, that would pay for a new and better battery pretty fast.

But yes, I agree with you that we need to know more. It's all speculation at this point.

 

[DaveEV]

Thus they don't have to build so many expensive natural gas turbine plants, and don't have to keep so many of them idling burning fuel to be ready to instantly deliver power when demand peaks. Instead they could draw power from thousands of EVs for a short time (a few minutes?), just long enough to spin up some other less expensive reserve generation capacity.

Simple gas turbine peaker plants are CHEAP to build (like $0.40/watt) - and so is the gas that fuels them. In terms of generation capacity, gas turbine plants are the cheapest to build.

Realistically - how much would you be willing to pay for a 24 kWh battery for grid regulation knowing that you'll only get paid about $2.50/day for the benefit? Assuming that the battery will last for 10 years before it needs replacement - that gets you about $9000 in revenue.

Until the externalities of burning fossil fuels is more accurately factored into the cost of generation - there is going to be little incentive for widespread V2G applications. By the time that occurs, it will probably be more cost effective for the utility to use 2nd hand batteries (eg, LEAF batteries with less than 80% of their original capacity) where they will be able to consolidate these packs into larger units (only have to worry about 1 big pack per neighborhood vs 100) - so management will be cheaper, too.

 

[LEAFfan]

For example, houses in CA typically use about 500 kWh/month or 20 kWh/day, compared to high usage areas which use about 1000 kWh/month or 40 kWh/day. Of course, depending on your typical usage patterns, YMMV.

A typical home in CA only uses on average 500Kwh/mo.?! That either has to be a really small home or they don't use A/C/Heat very much. Our home is 1500 sq. ft. and our ave. use is a little over 800Kwh/mo./10K/yr. which is much less than other same sq. foot homes in our neighborhood, and that was before the PVs.

 

[DaveEV]

A typical home in CA only uses on average 500Kwh/mo.?! That either has to be a really small home or they don't use A/C/Heat very much. Our home is 1500 sq. ft. and our ave. use is a little over 800Kwh/mo./10K/yr. which is much less than other same sq. foot homes in our neighborhood, and that was before the PVs.

Yep, typically very little need for heat or AC here in CA. Now you know why so many people live here. Hardly anyone in my neighborhood has AC / and if they do, typically only use it during heat waves. Heat usually comes from natural gas furnaces.

 

[raylev]

This is just for anyone interested in one homeowner's electric consumption data, not meant to be typical.

I have been collecting monthly electricity use data on my house in the SF Bay coastal area (no A/C) since 1997. Back then it was 1,800 sq. ft., and I averaged 8,600 kWH per year (715/month) for 1997, 1998 & 1999. I got a Ford Ranger EV in February, 2000, and our first year electricity use jumped to 12,300 kWH (1020/month)! My PG&E meter got changed to Time of Use at the same time, so I started checking it almost on a daily basis to see what the off-peak impact of charging the EV was.

Needless to say, we changed our charging behavior and did some energy efficiency work, and we got our annual use down to an average 9,510 kWH (790/month) for 2001-2004 or about 10 percent over the original consumption.

The next year (2005) we added a 1,000 sq. ft. second floor addition, and our consumption, including the EV, has averaged 11,800 kWH per year (982/month) ever since, although the last two years have been under 10,000 kWH.

I am not sure this is typical, but it looks like we averaged 4.8 kWH per sq. ft. per year before the EV, 5.3 kWH per sq. ft. per year after the EV, and then dropped to 4.2 kWH per sq. ft. after the remodel, which included many more energy efficiency work, including all new windows, roof, insulation, etc.

This all be off topic, and only represents one homeowner with an EV, but I have been waiting a long time to to share all this data.

BTW, I am waiting for my new Leaf to arrive in June, and yes, I have been driving the Ranger EV for over 11 years, with more than 53,000 miles on the original NiMH battery pack. The real-world range has dropped from 55-60 miles per charge to about 35-40, but it still works for my daily commute and errands. That also means over 4,000 charging cycles, as I plug it in nearly every day.

We are now considering installing solar PV panels, as peak power costs about $0.30/kWH, so one kWH offsets about 6 off-peak kWH, which is still going for about $0.05/kWH. With the new 30 percent federal tax credit, and $4/gallon gas, we are figuring on a much quicker pay back...

 

[jstack6]

If you read the website www.v2g-101.com you can see how it pays you and the power company to be connected 2 way for simple power regulation . Thta's just a quick 1 minute or less charge or discharge. It called tickling the battery and makes a big difference to power regulation (keeping freq and load in sync).

Denmark now has an EV that does V2G and is using it. The Univ of Delaware and Google are running testes on it in the USA. It's the neext big leap for energy.

 

[TomT]

Wow, I'm in the L.A. area and I typically use about three times that amount on average...

For example, houses in CA typically use about 500 kWh/month or 20 kWh/day.

 

[DaveEV]

For example, houses in CA typically use about 500 kWh/month or 20 kWh/day.

Wow, I'm in the L.A. area and I typically use about three times that amount on average...

Here's a link to some data. If you Google "average california electricity usage household" you'll come up with more data. 3x that - how big is your house and how much do you run the A/C? Our 2000 sq/ft house with 4 residents is a bit below average. We could be doing better!
http://www.physics.uci.edu/~silverma/actions/HouseholdEnergy.html