## BMW i ChargeForward Program to demo contribution of intelligent EV charging to grid efficiency

##### 05 January 2015

At the Consumer Electronics Show in Las Vegas, BMW announced the BMW i ChargeForward Program—a pilot study to be undertaken by the BMW Group Technology Office, together with Pacific Gas & Electric Company (PG&E). Working with a select group of BMW i3 drivers, BMW i ChargeForward will demonstrate how intelligent management of electric vehicle charging can contribute to improved electric power grid efficiency while reducing total cost of electric vehicle ownership.

BMW i ChargeForward is designed to explore how to better match the impact of electric vehicles with other dynamic energy supply and demand sources. The study has two parts, a managed charge pilot program involving BMW i3 owners and a battery second life energy storage system. In the managed charge pilot program, select BMW i3 owners will allow PG&E to request a delay in the charging of their vehicles by up to an hour, when grid loads are at their peak. The program also includes a “second life” for used MINI E batteries, by repurposing these batteries into a stationary solar-powered electric storage system located at the BMW Technology Office in Mountain View, California.

Grid efficiency through managed charging, combined with a used EV battery “second-life” system. The goal of the pilot is to provide PG&E with 100 kilowatts of capacity at any given time, regardless of how many BMW electric vehicles are charging, as part of a voluntary load-reduction program known as “Demand Response.” The benefit to PG&E of more efficient use of existing power grid resources through EV charging management is passed on in the form of monetary incentives to program participants. Improved grid utilization, resulting from EV charging management combined with a solar-powered “second-life” battery system, is expected to reduce stresses on the grid while supporting the integration of renewable energy.

Program participation. Up to 100 BMW i3 drivers located in the San Francisco Bay Area who complete a pre-qualification survey at www.bmwichargeforward.com, starting in January 2015, will be selected to participate in the managed charge segment of the pilot from July 2015 to December 2016. Throughout the 18-month pilot, BMW will manage the charging of participating BMW i3 vehicles, while prioritizing the e-mobility needs of participants based on timing by which vehicles should be fully charged, as communicated through a smartphone app.

For each program “event,” when PG&E experiences peak load conditions, participants whose vehicles are selected for delayed charging will receive a text message notifying them that their vehicle will stop charging for up to one hour, thereby temporarily reducing the load on the power grid. Using the BMW i ChargeForward smartphone app, participants can opt out of any request based on their driving needs, and their vehicle charging will continue uninterrupted—for example, if they need to depart for a trip during peak load times and need a full charge sooner.

As an incentive for participating, selected drivers will receive $1,000 initially, and an additional reward of up to$540 at the conclusion of the program, based on their level of participation in charging Demand Response “events,” as well as participation in occasional BMW or PG&E sponsored surveys or questionnaires.

BMW will begin accepting applications at www.bmwichargeforward.com in January, and the program will kick off in July 2015.

EV battery “second life” system using MINI E vehicle batteries. The battery second life portion of the project involves a full-scale stationary energy system built from eight used MINI E batteries to store energy and return it to the power grid. This 200 kWh system, located at the BMW Technology Office in Mountain View, California, is one of the largest second life systems in the world.

At the end of a vehicle’s life, these batteries still have at least 70% of their original storage capacity available, making them suitable for re-use. By removing them from the vehicle and installing them in a stationary storage system with integrated solar power generation, new renewable capacity can be added to the grid—supported by resources that once took energy from it. This additional power will supplement the energy load reduction by intelligent management of BMW i3 charging, to ensure PG&E grid needs are met, based on signals sent to BMW by PG&E as part of Demand Response.

BMW i Home Charging Services. Separately, but also at CES, BMW introduced BMW i Home Charging Services—a solution for home charging of electric and plug-in hybrid BMW models based on the smart home-enabled BMW i Wallbox Pro system already presented by BMW in spring 2014.

Using BMW i Home Charging Services, the vehicle is charged with home-generated solar power whenever this is available. At other times, or if the household does not have a solar generating system, the vehicle is automatically charged at the cheapest off-peak rates. This makes it possible to take advantage of flexible electricity pricing that varies depending on the time of day. In the USA, this can result in savings of up to $800 per year. With this fully automated charging service, customers get a simple-to-operate system that integrates vehicle charging with the household electrical system and online-based data systems. In Las Vegas, BMW is staging a live demonstration of BMW i Home Charging Services, which was jointly developed by BMW and Beegy, a provider for distributed energy-management, based on the Beegy Software Platform. In this demonstration, a solar carport supplies solar power straight to the BMW i Wallbox, which uses it to charge the vehicle. The system also uses real-time solar power data and home energy data supplied by Solarwatt and Kiwigrid. A screen at CES displays real-time weather data, together with solar power forecasts, showing visitors how BMW uses such forecasts to optimally manage charging times. Even if the sun is not shining, real-time electricity pricing data from Genability can be used to ensure that the vehicle is charged when electricity rates are at their cheapest. The Home Charging Services demonstration in Las Vegas also gives BMW the opportunity to present a concept product: a stationary energy storage system built from repurposed batteries previously used in BMW i electric vehicles. Energy fed to this home storage system can subsequently be used to charge an electric vehicle or to meet household power needs. ### Comments I would like to see more research with numbers attached to show how the efficiency of second life batteries declines in line with capacity reduction or aging. This could provide a return trip efficiency curve that translates to a$ value of the used battery.

While re purposing appears be viable at even low efficiencies, there is very little understanding of the losses (presuming resistance generated) This should ideally include chemistry specific qualities. It would help crunch numbers with respect to related hardware needs (which can be quantified).

Putting numbers to this could well influence consumer's vehicle choice and would be an important metric for manufactures but a deal breaker for anyone in the business of re purpose or storage installations.

It would seem that the latter I.E. installers would find this important metric to be poorly understood if at all. It would seem that enough preliminary trials have been concluded and in progress to prove the concept so that it is now timely for industry applicable knowledge to be compiled into some useful form guide.

Once you have a computer controlled charger, there is no reason at all to just start charging and keep going until you are finished. That would be SOOO 20th century.

What they are proposing is perfectly sensible and obvious.
When you plug in, you really want to tell them how much power you want, and by when; or perhaps, how miles you require, and by when.
Or, it might learn what you do, and do it automatically.
Thus, if you have a 120 mile car, and drive 30 miles to work, there is really no need to charge at all when you get to work, but you might top up if there was a lot of wind or solar on the grid.
Also, it could charge at night (duh), but it might skip a night if there was a lot of wind predicted for tomorrow night, or wait till later on (say after 3am) if there was a lot of wind on the way.
Once you have cars with a "non breadline" battery (say >= 35 kwH), you can start to do lots of tricks like that.
If you are short of battery (like a Leaf), you pretty want to top up all the time (but you still could postpone till later on if wind was on the way).
This won't deplete your battery as V2g would so it is a bit of a no-brainer to join for $1000! Good point, So much smarts included, chargers should be up to it. But with so many chemistries a database of end of life expectations will be a big help to estimate the residual value of different packs as they become available. "I would like to see more research with numbers attached to show how the efficiency of second life batteries declines in line with capacity reduction or aging." Arnold, the efficiency of the batteries does not change any significant amount at all, unless you are using excessive high rates of charge or discharge which cause the pack to heat up excessively. The internal resistance of a battery does go up as it ages, so there will be some reduction in efficiency, but at typical grid service loads of 0.5C to 1C, it should be just about negligible. "But with so many chemistries a database of end of life expectations will be a big help to estimate the residual value of different packs as they become available." Now there you have an interesting problem: how do you judge the value of a car with 50000 miles on a 24 KwH battery ? Or one with a 85 KwH battery. You need a set of tables for each battery type, OR a test which can at least say what the charge capacity of the pack is (+ a table for degradation). So who would make the tables ? NIST maybe. Alternately, a sort of grey market appear with rule of thumb pricing and people could take their chances. You would imagine that people with Solar arrays or people on Islands would buy a few, to see how they went. Instead of$1 per gasoline gallon equivalent electricity, figure it is more like \$3 with road taxes and battery replacement fund. However, that battery replacement fund does not go with the car, so it is reflected in reduced resale value.

People are wary of EVs because they have short ranges and high prices, now they have the valuation of a used vehicle with an old pack. This will not help the sale and resale of EVs until a method can be determined to set the real value of the car.

@ Dave,

At the risk of appearing more ignorant than I may appear,your comment is in line with other comments and references on the matter.

Trouble is I find it hard to accept.

I would have thought it obvious (until I can understand this better) that pushing electrons through resistance generates heat while current flows.

That any machine in operation pushing electrons will in this less than perfect world have idling losses that increase by time.

Surely a battery with high resistance will have both those characteristics.

Certainly my practical experience (no test gear just feel) with domestic garden variety any chemistry batteries on transformer or switch mode charging including multimode or strategy chargers puts those losses at rather concerning levels.

That is as you point out a heat effect - but also by failing to reach the set voltage point in a timely manner with the possibility that those standing losses and resistance losses continuing until someone turns the device off and removes said pack from service.

I note that battery analysers are being marketed to the (motor)trade that have low amp >1A?~.5A from memory.
They seem to be not expensive but I ham not sure how reliable they are.

As we know that the cost of smart chips is so small as to insignificant and there are certainly algorithms and strategies for determining battery efficiency and state of charge, again not sure if that requires a full cycle or more to gather enough knowledge of the test bat.

Something along those lines would be very informative and accurate (if it exists) but that won't help buying say unsighted (sight unseen)

SJC,

I would be one of those anxiety filled consumers but the head suggests that assuming due diligence, that is already unreasonable.
I am confident that the expected improvements under development will deliver above most peoples expectation (life of car 20years).
Guess everyone's priorities are different and expect ev's will win out by virtue of lower lifetime costs,versatility and practicality together with better performance in every department as that is what consumers have learned to demand.

Deferring a charge by a day means the battery will be cycled more deeply, which increases wear.  Compared to that, the very shallow cycling of V2G regulation service would do nothing; the AC Propulsion V2G regulation test even increased the capacity of the Panasonic battery pack.

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