Cody Hyman
The Base Load Power Plants Always active and feeding the grid Mostly Coal and Nuclear
Intermediate and Peaking Power Plants Activated when power demand increases Includes smaller fossil fuel plants and
hydroelectricity Supplemented by forms of Alternative
EnergySource: http://www.opc.com/PoweringGeorgia/TypesofPowerPlants/index.htm
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
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 2009Current 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
Most surplus energy, if there is any, is lost
Organizations managing the grid predict load curves ex: the California ISO
Number of connected generators is varied Spinning reserves and peaking plants
supply extra power during peak demandStored energy is sometimes fed into
the grid
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 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-energy-storage.htm >.1-http://www.mercurynews.com/business/ci_13210674?nclick_check=1
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>
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) 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>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.
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
Image Source: University of Delaware<http://www.udel.edu/V2G/page2/page9/files/pasted-graphic-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 Pricing changes or appliance-specific lockouts
will influence Example: Increased cost of running large
appliances during peak load hours 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>
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.horizonutilities.net/HHSC/assets/images/SmartMeter.jpg
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_workshop.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/>
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