Two-Way Charging Electric Vehicles Start To Earn Money From The Grid In The US

APR 27 2013 BY JAY COLE 14

In Delaware, fifteen Mini E models that have been donated by BMW, are currently being utilize to “balance the grid” by drawing and selling energy at appropriate times in a project lead by the University of Delaware.

V2G Is Already A Reality In Japan.  Here A Nissan LEAF, Through A Nichicon Charging Station Puts Stored Electricity Back Into The Grid

V2G Is Already A Reality In Japan. Here A Nissan LEAF, Through A Nichicon Charging Station Puts Stored Electricity Back Into The Grid

While V2G (vehicle to grid) is not a new concept, Nissan has been featuring chargers with this functionality in Japan, it is a new way of thinking in the US.

The Mini Es are equipped with a two-way battery charger, and a slightly modified on board receptor.

Professor of electrical engineering and computing, Willett M. Kempton says that each of the 15 Mini Es earn about $5 a day when the sharing system is active; which of course equals about $150/month or $1,800 a year….making the prospective of EV ownership even more attractive

In a interview with the NY Times, Michehl R. Gent (no we did not mis-spell his first name), a former president of the North American Electric Reliability Corporation, said that the University’s project was “tiny but promising.”       

“If we can get our electric vehicles to do more than just be electric vehicles, it will be very well received,” said Mr. Gent, who is not associated with the project.”

Professor Kempton explains that the MINI E’s listen for a signal from grid operator, that gets pinged out every four seconds. That signal in turn tells the batteries the ideal times to charge, discharge, or just idle.

Also, if the cars are in need of charging, they can alternate the amount of current they draw at certain times in order to add or subtract from the overall load of the grid.

Check out a rather in depth article on the project and its value to the future of both electric vehicles, and the grid itself here (NY Times).  Hat tip to Michael T.

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14 Comments on "Two-Way Charging Electric Vehicles Start To Earn Money From The Grid In The US"

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I wonder how well the battery is thermally maintained and what this does for the warranty as its effectively like adding miles to the battery without driving it. In the deeper NTY article it says they are shifting upto 18kW, which can produce a lot of heat. Also never addressed how to ensure the car has enough charge when you need it? Trying to understand the financal implications. To make money it must provide power and its hard to see why the value to the power-company would be worth more than the peak/off-peak spread. My companies difference my TODU is .08/kWh (100% increase), so maybe in delaware it might be double, say .15/kWh. So so make $5/day that is would imply a transfer of about 33kWh of added charge/discharge per day. For an efficient driver, with 4 miles per kWh, that is about like adding 120miles added per day on the car’s battery. Even with a TMS, not clear to me it would be worth the wear/tear on the battery. For example with the warranty of 100K miles, and assuming an efficient driver getting about 4 miles per kW, that is expecting a total battery draw over its life time… Read more »

The concerns on the battery fatigue are definitely real and will probably be what holds this back from really hitting the market.

As far as payback, it will vary widely based on your location. In Texas, on ERCOT, there is a cap for peaker power at $3.00 / kWh. This limit has been hit on the very hot summer days.

I think the story here is the implied value of the electric car when not used primarily as an EV.

These MINI Es are several years old, off their fleet-test leases from as early as June of 09, I imagine many have 75K, 100K or more on them. 7 or 8 of these in this project are used as grid swaps only, they are not driven at all.

If you can hook up any dated EV to the grid and get almost $2K, that sets a floor on the residual worth of even an undriveable EV north of $8K.

Looking at it another way; an person could lease a LEAF/i-MiEV/SMART ed for less than the amount of revenue a program like this generates per month, and pocket the difference, while still getting an EV to zip around when you need it. Who cares what the grid is doing to it?

I hear what your saying Jay, but I would say that the same is true for the battery without the vehicle. If they develop a system for a driver to replace/upgrade their pack and use the old one for grid firming, a true market will appear.

That’s what I was thinking. How much can I buy a battery for? Say $3000. If I hook it up to the grid, after 1.6 years I’m making money, at a rate of $5/day.

You definitely hit this one right on. Few discuss this, but it’s so true. You make some money…sure…but it’s not worth it

You are basing your concerns on current battery chemistry. I agree that I would not sign on with my current battery, but this is almost certainly going to improve in the next five years and possibly change in ten. Planning the smart grid will take at least as long. The real question to me is how much battery energy is left after the afternoon drive home from work for that is what will be available to the grid. In ten years hopefully there will be chargers in the workplace so that the charging top off will begin early and a calculated amount will be available during peak hours.

As long as you
Do not break Newton’s three laws of physics.
Have enough money for research
And can conceive and define the problem
You can bet that engineers will solve it. It’s what we do.

Great for emergency back-up power for your home but not for what they are doing with it… you’ll kill the battery faster…..


We are seeing some very good results with high-mileage EV’s which are not located in extreme climates, so as long as the battery is kept between 20-80% capacity while charging and discharging, and the battery temp kept stable, we might not see much degradation beyond normal. I’m all for using EV’s in this way to help the adoption of solar and wind if it is a net positive for all concerned.

Isn’t this also being tested at Pecan Street in Texas? All the smart grid tech?

On Pecan Street they are just tracking the EVSE usage and turning the chargers on and off. I don’t think electrons actually flow back onto the grid.

Texas does have a large grid battery project (1 MW, 1 MWh) that is getting installed near Lubbock this year.

Ok, the only reasonable use for this type of thing, is to avoid ‘spinning reserve’. I’m not aware of any Utility doing this for any length of time, and if they are doing it, they should stop it since its a waste of resoures..

Now, the complication here is that the ‘spinning reserve’ can also mitigate reactive power problems. I suspect that is the primary reason for the SR.\\

The real way to take care of this problem is to take care of Reactive capacity and minimize otherwise Spinning Reserve.

@Dr Innovation

Ok so if you’re working on the spread from 8 cents at night to 15 cents in the afternoon, what is the battery cycle efficiency charging / discharging? I’d be really surprised if it was as high as 75% . Then how much of a fee is your utility going to charge you to “Deliver” this energy to your next door neighbor?

By the time these real world costs are added, I wouldn’t think it would be anywhere near worth the added wear and tear on your battery…

But if you still like the idea, better your battery than mine.

“V2G Is Already A Reality In Japan. Here A Nissan LEAF, Through A Nichicon Charging Station Puts Stored Electricity Back Into The Grid”