Co-author Emma Spath
In the midst of the Fukushima Daiichi nuclear disaster in March 2011, electric vehicle (EV) batteries were used in an unusual and innovative way—as energy storage. The earthquake caused a plant shutdown, but the following Tsunami waters damaged the back-up diesel generators responsible for cooling the plant’s systems. Many do not realize that as the situation in the nuclear reactors became increasingly dire and with no ability to generate power onsite, the Tokyo Electric Power Co. (TEPCO) brought in fully-charged EV batteries to supply electricity, restart the pumps, and reestablish steady water circulation for cooling. Fukushima demonstrated to the world that EV batteries can not only be used for transportation, but also as mobile power sources able to resupply the power grid.
Use of EV Batteries for Storage is Growing
Elsewhere in the world, traditional EV batteries are gaining support not only to power vehicles, but also as battery storage. For example, car manufacturer Nissan has partnered with Canadian electric company PowerStream to pilot tests to determine the potential of using its popular model, the Nissan Leaf, for battery storage. The concept has been called Vehicle to Home, or V2H, and the vehicle would essentially communicate with the power grid, its charging station, and the house to determine when and how much electricity is needed in times of grid strain, such as brownouts in heat waves, or general power outages. Additionally, V2H could be used to avoid peak energy demand charges. Nissan states that the 24 kWh of energy could power the average home for 24 hours without power conservation attempts. The special V2H charging station also has the load capacity to power common household appliances at the same time.
Elon Musk and Tesla have introduced the $3,500 Powerwall, to be delivered in late 2015. Based on the technology used in the Tesla Model S battery, the Powerwall is a home battery that charges using electricity generated from solar panels and has the additional benefit of automatically recharging in the middle of night when energy demand is at its lowest. This new technology may be most feasible for someone who already has solar panels and a power inverter installed, so one can avoid buying an additional ac/dc inverter.
In April 2015, Musk also unveiled the Powerpack, a $25,000 version of the Powerwall for businesses. Even before the public announcement, Walmart signed a deal with Tesla to test its stores with Powerpacks in conjunction with existing solar panels. Musk informed shareholders at the April announcement that as much as 80% of the non-vehicle battery business will likely be to utilities and large industrial customers like Walmart.
Recycled EV Batteries for Power
Companies are getting involved in EV batteries in a different way—recycled EV batteries. Recycling EV batteries extends their life and prevents the immediate disposal in landfills. The typical lifetime of an EV battery is 10 to 12 years, but after the batteries have exhausted their use within a vehicle such as the Chevrolet Volt or Nissan Leaf, the batteries still maintain up to 80% of their capacity. For example, Chevrolet is currently using five recycled Chevy Volt batteries to power the new General Motors Enterprise Data Center at its Milford Proving Ground, helping the Center to annually deliver net-zero energy use. The batteries also provide back-up power to the building for four hours in the event of an outage and can provide excess energy to the grid that supplies the Milford campus. Because electric car sales are currently depressed in Japan and in the United States thus causing supply to be low, time will tell if recycled EV batteries will cause a significant and broad energy impact.
Through Tragedy Comes Opportunity
The future for EV batteries as storage should gain additional momentum due to a 2013 order from the California Public Utilities Commission, which requires Edison, San Diego Gas & Electric and Pacific Gas & Electric to install or contract for more than 1,325 megawatts of electricity storage throughout the state by 2020, thus creating a significant market for batteries such as the Powerwall and recycled EV batteries. Additionally, the Department of Energy is conducting extensive research on EV batteries, including ways to reduce size and production costs, both of which may make use of new EV batteries as storage more feasible. Although in some ways the use of EV batteries as storage was brought to the public eye by a tragedy, the future for this type of battery storage has serious potential, especially as more technological improvements are made regarding size, weight, capacity and costs.