Vehicle to Grid Electric Vehicles as Grid Storage Andrew Levitt
Project Manager for Vehicle-to-Grid project sponsored by NRG Energy
and University of Delaware Slide 2 Transition to Carbon-free Power
Those most concerned with climate change envision a world with very
limited carbon emissions This would entail a radical increase in
use of variable electricity generation from wind and solar Slide 3
Grid storage Slide 4 Today, fuel storage and dispatch accomodates
variability and unpredictability in electric load Day 1Day 3 Day 5
Day 7 Electric load (GWh) Slide 5 99.9% renewables on Mid-Atlantic
grid Day 1Day 3 Day 5 Day 7 GWh Budischaka, et al, 2013. J. Power
Sources. Slide 6 A hard week of all-renewables Day 1Day 3 Day 5 Day
7 GWh Budischaka, et al, 2013. J. Power Sources. Slide 7 Electric
energy storage allows avoidance of fuel storage Slide 8 Electric
vehicles Slide 9 Electric Vehicles. Consider: 1.There are about 200
million light vehicles in the United States. 2.In low-carbon world,
most would (debatably) be electric vehicles. 3.An electric vehicle
is necessarily a substantial investment in: Energy storage 100
kilowatts of two-way power conversion from battery to electricity
4.Cars are unused for about 23 hours per day 1. 190 million. US US
Bureau of Transportation, 2013. 2. Shoup, 2005. The High Cost of
Free Parking. Slide 10 If half of US cars were electric: Electric
vehicle power capacity 100 million x 100 kW = 10,000 gigawatts ~10x
the peak capacity of the US grid Electric vehicle storage capacity
100 million x 40 kWh = 4,000 gigawatt-hours Enough to run the US
grid (at average load of 500GW) for 8 hours Of course cars need to
drive Slide 11 Maximize Value Bidirectional power flow: enable
multiple electric services, and allow continuous participation Use
motor drive electronics for charging/ discharging -- negative cost,
high power High power (e.g. push to J1772 limit of 19 kW) Slide 12
User conveinence of high charge rate Charge rateMiles added per
hour* J1772 level 14 kW16 J1772 Full spec19 kW76 IEC 62196 (3
ph)44-52 kW180 CHAdeMO (DC)50 kW200 *4 mi/kWh. IEC62196 in EU=44kW,
in US=52kW Photo credit: Tim Shaffer, NY Times Slide 13 Costs of
using electric vehicle as grid storage Control electronics on car
and charging station (currently ~$400 each) Battery wear
Administrative and scheduling time Cost per kilowatt: $27/kW Cost
per kilowatt-hour: $13/kWh Compare to purpose-built storage Slide
14 Battery wear Depending on chemistry, decrease of battery life
may be expected when exercised under certain conditions: Very high
or low state of charge Very high sustained charge or discharge
current More full-charge cycles Determining what and how much
impact V2G has on batteries is a goal of current research. Slide 15
Vehicles comprise a mostly-idle capital investment in enormous
power production and energy storage. It is low cost to harness this
resource for grid-connected energy storage. Slide 16 Grid services
Slide 17 V2G value Grid balancing services (grid operators) Defer
distribution investment (utilities) Arbitrage (energy markets)
Limit demand charge (commercial consumer) Firming and leveling
renewables (wind operator or grid operator) Etc.. Slide 18 Grid has
to balance supply and demand at each moment Scheduling of
generation and load accomodates almost all of this. Unpredictable,
instantaneous inaccuracies are compensated by fast balancing
reserves (below). Two hours of response by balancing reserves in
PJM on June 5, 2013 One Hour Slide 19 V2G in operations With this
fast balancing service, battery state- of-charge stays between 50%
and 75% It does not drain the battery A trip scheduler triggers
charging of car to full capacity when needed. Slide 20 Balancing
reserves market 2013 average price of 3.0 per kilowatt-hour
Corresponding revenue is $320 per month with 18kW charging at home
and work, accounting for charge time for driving. Slide 21 Fast
grid balancing provides several hundred dollars in gross revenue
per car per month. Fast grid balancing does not drain the battery
of an electric car. Slide 22 V2G Project Photo credit: Tim Shaffer,
NY Times Slide 23 Project Collaborators Slide 24 History
Preliminary V2G system developed by University of Delaware in 2007
and launched with 3 vehicles in 2008 NRG Energy bought a stake in
the technology in 2011 Milbank Manufacturing licensed the V2G
charging station in early 2012. BMW finalized donation of a fleet
of purpose- built all-electric MINI Es in early 2012. Also engaging
several major japanese carmakers and domestic electric truck
manufacturers. Slide 25 Status First ever payment by a grid to a
car was for services on February 27 of this year Operating with a
stationary test bed plus 3 fleet cars since February Generating up
to $5 per car per day providing balancing reserves Continuing to
refine technology for release to small number of test drivers.
Still open for fleet participation. UD-developed, V2G-enabled
Milbank charging station soon to be commercially released Currently
looking to expand to other grid operator territories Photo credit:
Tim Shaffer, NY Times Slide 26 END Andrew Levitt
[email protected]
