1. The Synergy of Plug-in Vehicles in Micro-grids
Peter Lilienthal, Ph.D.
CEO, HOMER Energy
peter@homerenergy.com
Automotive Research Center Conference
May 24th, 2011
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2. What is a Microgrid?
Set of loads and generation sources capable of autonomous islanded operation
Microgrids make EVs more valuable
And vice versa
Reliability
Renewables
Smart grid
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3. Background and History
Remote and island grids are not new
Grid-connected microgrids are coming
Dependent on liquid fuels from petroleum
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4. 3 Disruptive Innovations
Electric vehicles
Distributed controls
Low cost PV
Grid Parity
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5. PV Price Trend
http://srren.ipcc-wg3.de/ipcc-srren-generic-presentation-1
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6. Clean Power Evolution
Large utilities have security and regulatory obstacles
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7. Microgrids and Plug-in Vehicles
Grid benefits of distributed storage
Save fuel and $s
Stabilize the grid
Reliability
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8. Economic Benefits
Long term storage (hours)
Throughput costs ~ $0.40/ kWh in battery wear
Only economic now for small loads

Short term storage (minutes)

Variable renewables => more spinning reserve
Generators have:
Minimum load constraints
Ramp rate constraints
Low efficiency at low load

Storage is a better reserve resource

9. A little storage goes a long way2334 Broadway, #B, Boulder, Co. 80304www.homerenergy.com
10. Grid stability
Benefit to both microgrid and central grid
Frequency and voltage control
Renewable contribution
Diesel-off operation
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11. Local Reliability Benefits
Storage for short outages
Hybrid renewables for extended outages
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12. Types of Vehicles
Battery size
Pure EV or hybrid
V2G or Smart Charging
Power transfer capability
110 volt x 30 amps = 3.3 kW = 4hp
220 volt x 50 amp = 11 kW = 15 hp
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13. Types of Microgrids
Remote microgrids
Global experience
Alaska and Australia
HOMERs 60,000 users in 193 countries
Grid-connected microgrids
Reliability requirements
Sustainability mandates
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14. Too Many Choices
Solar
Fuel Cells
Wind
Micro-turbines
Hydro
Geothermal
Micro-grids
Biomass
Demand Response
New Storage Techs.
Electric Vehicles
Load Management
Smart grids
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15. What is best?
Depends on the application
Resources
Loads
Equipment prices
Equipment performance
A confused mind says No!
Hybrid optimization with the HOMER software
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16. HOMER History
1993 Village Power
Internal NREL use
2001 Public version 2.0
Larger grid-connected systems
2005 Plug-in vehicle
Internal NREL use
2009 HOMER Energy spun off
2011 Version 3.0
Ease of customization
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17. Conclusion
EVs & microgrids: a perfect match.
Grid integration is important.
The HOMER software can help.
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