Cody Hyman
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The Base Load Power Plants
 Always active and feeding the grid
 Mostly Coal and Nuclear
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Intermediate and Peaking Power Plants
 Activated when power demand increases
 Includes smaller fossil fuel plants and
hydroelectricity
 Supplemented by forms of Alternative Energy
Source: http://www.opc.com/PoweringGeorgia/TypesofPowerPlants/index.htm
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The greater the demand for power, the more
current the power plants must provide
Power companies need to provide a relatively
constant AC voltage and frequency to
customers
The power transmission and distribution grid
of a developed nation like the US is an
incredibly complex and constantly changing
circuit
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Large Fluctuation Between Day and Night
Power Demand (lowest demand may be
around 60% of peak demand)
Grid must quickly compensate for changes in
demand
Additionally, demand varies by other factors
including the local climate and season
Image taken from California ISO state grid data for 13 October 2009
Current grid data can be found at http://www.caiso.com/outlook/outlook.html

If demand is too great, outages occur
 Dropouts, brownouts, and blackouts
 Rolling blackouts are created intentionally to keep
the grid partially up while demand is too great for
the grid to support
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Most surplus energy, if there is any, is lost

Organizations managing the grid predict load
curves
 ex: the California ISO
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Number of connected generators is varied
 Spinning reserves and peaking plants supply extra
power during peak demand

Stored energy is sometimes fed into the grid
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Some energy can be stored for use during peak hours
 Only a small fraction is stored currently due to the expense
of storing energy
Intermittent power sources such as wind and solar
may suddenly stop generating power, causing a large
droop in the grid
 Storage methods include
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Batteries (Very efficient, but expensive)
Pumping water for hydroelectricity
Gas Compression1
Flywheels (Steadying Voltage and UPSs)
HowStuffWorks. Grid Energy Storage <http://science.howstuffworks.com/earth/green-technology/sustainable/community/grid-energystorage.htm >.
1-http://www.mercurynews.com/business/ci_13210674?nclick_check=1
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Great increase in total grid demand as more
electric vehicles are put on the road
Off-Peak Night Charging to fill “valleys” in the
demand curve
 The Pacific Northwest National Lab estimate:
approximately 70% of an EV based American road
transportation system could be charged on
current generation capacity
 Would decrease the amount of necessary grid
expansion
PHEV Projections obtained from PNWNL:
<http://www1.eere.energy.gov/vehiclesandfuels/avta/pdfs/phev/pratt_phev_workshop.pdf>
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PNWNL estimates the following energy requirements
for hybrid electric vehicles with an average generator
to battery efficiency of around 68-70% (includes
transmission and distribution losses as well as charger
and battery inefficiencies)
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Compact Cars 0.26kWh/mi
Mid-Sized Cars 0.30kWh/mi
Mid-Size SUVs/Vans 0.38kWh/mi
Full Size SUVs 0.46 kWh/mi
The U.S. Bureau of Transportation Statistics estimates
that in the U.S. During 2006, there were 1.683x1012mi
driven in passenger cars and 1.089x1012mi driven in
other 2-axle 4 wheeled vehicles (vans and SUVs)
Per Mile Energy Cost:< http://www1.eere.energy.gov/vehiclesandfuels/avta/pdfs/phev/pratt_phev_workshop.pdf>
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BTS Mileage Data:< http://www.bts.gov/publications/national_transportation_statistics/html/table_01_32.html>
A rough assumption based on my own calculations of
the data puts annual passenger car/SUV demand at
900-1000TWh (1PWh)
 Peak Generation Output of US Generators is approx
1.1TW, assuming maybe 900GW are in operation at all
times, around 7900TWh could be generated annually.
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The EIA also estimates the addition of around
20GW of generation capacity annually
Current demand averages around 640-780GW
 In reality only some regions can currently cope with a
heavy EV demand (Midwest has the capacity to currently
support a full conversion to EVs, the West Coast does not)
Power Generation Data from U.S. Energy Information Administration (EIA)
Potential to sell
electricity from an EV
back to the grid during
peak demand hours
 A single EV can likely
supply around 10kW
 Also could be used as
a source of emergency
power in the event of
a blackout. A nation of
electric cars could
potentially power the
grid for up to 5 hours
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Image Source: University of
Delaware<http://www.udel.edu/V2G/page2/page9/files/pastedgraphic-1.jpg>
A growing number of regions across the world are
implementing modern technology to power
distribution and metering
 Smart meters can be used to provide time-specific
electricity rates and cause non-essential power usage
to be rescheduled to non-peak hours
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 Pricing changes or appliance-specific lockouts will
influence
 Example: Increased cost of running large appliances
during peak load hours
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Smart Meters will likely be essential to the
implementation of a national EV fleet and V2G
technology
Source B.B.S. Electronics
<http://www.bbsgroup.com.sg/images/AMRsolution.jpg>
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Some regions and nations
are actively installing smart
meters
 Ontario, Canada will have
converted entirely over to
smart meters by 2010
 California and Texas also have
large scale implementation of
smart meters
 Also used extensively in the
UK and Australia
Image Source:
https://www.horizonutiliti
es.net/HHSC/assets/imag
es/SmartMeter.jpg
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Types of Power Plants, Oglethorpe Power
<http://www.opc.com/PoweringGeorgia/TypesofPowerPlants/index.htm>
Current Demand Outlook, California ISO
<http://www.caiso.com/outlook/outlook.html>
Blackouts, Virginia Department of Emergency Management
<http://www.vaemergency.com/threats/blackout/>
Pratt, et. al., Potential Impacts of High Penetration of Plug-in Hybrid Vehciles on
the U.S. Power Grid, Pacific Northwest National Laboratory, June 2007,
<http://www1.eere.energy.gov/vehiclesandfuels/avta/pdfs/phev/pratt_phev_wor
kshop.pdf>
U.S. Bureau of Transportation Statistics 2006 Vehicle Milage Data
<http://www.bts.gov/publications/national_transportation_statistics/html/table_
01_32.html>
Vehicle-To-Grid Technology, University of Delaware <http://www.udel.edu/V2G/>
Vehicle-To-Grid Technology Diagram, University of Delaware <Source: University
of Delaware<http://www.udel.edu/V2G/page2/page9/files/pasted-graphic-1.jpg>
Energy Information Administration Data <http://www.eia.doe.gov/>