NREL and partners to investigate secondary uses for electric drive vehicle batteries
06 April 2011
The US Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) will partner with an industry-academia team led by the California Center for Sustainable Energy (CCSE) to investigate secondary applications for aged battery packs from electric drive vehicles.
The cost of Li-ion batteries currently affects the affordability of plug-in hybrid and electric vehicles (PHEV/EV) for consumers. While these PHEV/EV batteries degraded to 70%-80% of their original power/capacity are insufficient for automotive use, these aged batteries may still be useful and could be reused in other applications. Such second-use applications could significantly increase the total lifetime value of the battery, and thus reduce its cost to the automotive user.
Researchers will do a technical and economic investigation to see if the potential for reusing Li-ion batteries could lead to consumers obtaining a cost credit for the remaining value of a used battery, potentially offsetting a portion of the initial cost to the EV buyer.
Possible secondary uses for lithium-ion (Li-ion) batteries include residential and commercial electric power management; power grid stabilization to help provide reliable electricity to users; and renewable energy system firming&mash;which in this case involves using batteries to make power provided to the grid by variable resources such as wind and solar energy more useable.
The project will begin with a comprehensive technical and economic analysis addressing all aspects of a battery’s lifecycle in search of the best second-use strategies, followed by a comprehensive test program to verify findings, particularly battery lifetimes. For the field test, researchers will deploy aged EV batteries at the University of California (UC), San Diego’s campus-wide electric power grid. The results of the study will:
- Provide validated tools and data on battery life to industry for battery reuse;
- Make recommendations for EV battery design and manufacturing practices;
- Identify the necessary regulatory changes to encourage secondary battery use; and
- Assess the economic benefit of second uses.
Allocating used electric vehicle batteries to second-use applications also could benefit the environment by delaying the recycling or disposing of batteries, and by supplying a service that improves the efficiency and cleanliness of other industries.
The CCSE project team includes the UC Davis’s Plug-In Hybrid Electric Vehicle Research Center; the UC Berkeley, Transportation Sustainability Research Center (TSRC); UC San Diego Strategic Energy Initiatives; San Diego Gas & Electric; and AeroVironment.
The NREL award to the CCSE team leverages an ongoing UC Davis-CCSE-TSRC study funded by the California Energy Commission on the repurposing of used EV batteries for home energy storage. The total budget for the NREL-CCSE second use battery project is approximately $1.3 million with 51% of the funding coming from CCSE and its partners.
In May 2010, NREL released a request for proposals (RFP) seeking potential partners in industry and academia to support a work package that includes evaluation of secondary use applications and battery optimization strategies, the acquisition of used automotive traction batteries, and demonstration testing in actual secondary use environments.
This activity is sponsored by DOE’s Office of Energy Efficiency and Renewable Energy.
Resources
A battery that has degraded to 70% of both power and capacity (energy) is not long for this world.. but a battery that is down to 70% of its total energy storage but can still deliver close to full power (internal resistance does increase with age) can still be used for grid stabilization, in these application the battery is cycled very shallowly back and forth, and that averages out.. in this task they can live a long time and provide a valuable service..
Posted by: Herm | 06 April 2011 at 09:15 AM
If cheap enough, people with future solar/wind power systems could use those old battery packs to operate 24/7 from clean but interruptible power sources.
Posted by: HarveyD | 06 April 2011 at 10:51 AM
Hasn't this already been done with ten year old Rav4 EV and Prius batteries, assuming some of them have loss 20% of their original power/capacity?
Posted by: kelly | 06 April 2011 at 10:52 AM
"people with future solar/wind power systems could use those old battery packs to operate 24/7 from clean but interruptible power sources"
I think what we would rather have is affordable ultracapacitors so that we would have to purchase storage only one time.
The less developed world is starting to get a fair amount of freestanding PV. Would that they had a better storage option than lead acid batteries. With UCs you should be able to buy one small capacity unit and then add more as desired. Can't do that with batteries, the old one pulls the new one's performance down.
Posted by: Bob Wallace | 06 April 2011 at 11:35 AM