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PEV Grid Integration 

Research

Vehicles, Buildings, and Renewables 

Working Together

Tony Markel

Sr. Engineer

Electric Vehicle Grid Integration

National Renewable Energy Laboratory

EPRI EV IWC Mtg. White Plains, NY

June 19, 2014

NREL/PR-5400-62244
2

DOE EVGI and INTEGRATE Research Efforts

• Electric Vehicle Grid Integration (EVGI) and INTEGRATE are 

addressing the opportunities and technical requirements for 

vehicle grid integration that will increase marketability and 

lead to greater reduction in the use of petroleum

• Address Core Questions

o Quantify use cases, performance, and life impacts of grid applications

o Contribute to development of open interface standards

o Identify and quantify potential grid integration values

• Vehicle-related Research Focus Areas

o Managed charging systems providing flexibility, demand response capability

o Bi-directional power to minimize local demand charge and grid frequency 

control

o Local power quality monitoring and enhancement value

o Emergency power system design enabling vehicles to support disaster 

recovery
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VTIF Vehicle Grid Integration Test Bed: Used to explore vehicle, 

grid, renewables, and buildings working together

Equipment Resources

• SCADA-configurable AC and DC 

distribution buses

• More than 10 EVSE points

• 18-kW solar array

• Battery and hybrid inverters for V2G

• High-power fast chargers

• Load banks for building scenario 

integration

• Power supply/grid simulator

VTIF=Vehicle Testing and 

Integration Facility

Source: NREL Dennis Schroeder Source: NREL Dennis Schroeder
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ESIF Resources for Vehicle Grid Integration Research

• More than 15 EVSEs accessible in lab spaces

• DC load bank to act as a programmable storage device

• Oscilloscopes for detail electrical system impacts analysis

4

ESIF=Energy Systems 

Integration Facility

EVSE=electric vehicle

supply equipment
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PEV Residential Distribution Testing

• Demonstrating grid impacts of simultaneous 

plug-in electric vehicle (PEV) charging on local 

distribution circuits

• 15 EVSE (charging stations) connected to 

ESIF’s REDB, grid simulator, and load banks

ESIF MVOTA

xf

ES

Source: NREL, M. Simpson

REDB = Research Electrical Distribution Bus
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Laboratory Resources Applied to Tech Introduction

Source: NREL, M. Simpson

Source: Burns & McDonnell

5x 60-kW Bi-directional Stations 

Integrated with Microgrid Operations Scenario 

Simulation

Tech 

Development

System 

Confirmation

Source: NREL, M. Simpson

VTIF

- Communications development and testing

ESIF

- Grid integration component verification
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120

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160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

peak demand (kW)

Federal Way Depot Monthly Peak Demand

2011

2012

2013

Frito-Lay EV Delivery Truck Case Study – Importance of Charge 

Management to Avoid Peak Demand Increase

• Frito-Lay North America (FLNA) operating fleet of 269 allelectric delivery vehicles

• Operational data from Smith EVs in FLNA’s fleet are monitored 

and reported to NREL as a part of Smith’s ARRA grant

PEVs, introduced 

in Jan 2013, 

nearly double 

demand

NREL PIX 28804
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Planning for PEVs on a Highly Renewable Campus
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Expanding Charging Data Streams and Interaction to Automate 

PEV Charge Management with Renewable Sources

Provide simple interface with 

least information necessary to 

create managed individual and 

aggregate scenarios with status 

display

RSF = Research Support Facility
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Building Integrated Charge Management 

Implementation Strategy

Primary parameters

• Parking location

• Research vehicle?

• Person ID  vehicle type

• Current time

• Next departure time

• Target energy/miles 

remaining to be delivered

• Calculate a “flow 

reservation”

– Schedule when energy will be 

delivered and at what rate

Significant challenge in collection 

and aggregation of driver and vehicle 

needs and attributes

NREL PIX 26667
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Why Integrate Vehicles with Buildings

• Building demand charges make up 20%–40% of typical electricity 

expenditures

o Demand charges are based on peak load during 15-min window, a few events 

per month

o $132B/yr in commercial electricity expenditures

– 1% demand charge market ~$420M/yr

• V2B operates “beneath the meter” 

o Minimal need to interact with utilities or markets

o Can make local use of local assets (such as distributed renewables)

• Requires short duration discharges (often <1.5 hour)
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Demand Charge Management in Commercial Facilities

• Assessed 98 facilities using 1 year of 

historical 5-min interval data from 

Enernoc

• Optimal system sizes were generally less 

than 20 kW and 10 kWh – well suited for 

BEV and PHEV batteries

Journal publication in process.

No. of Facilities

20kW 10kWh
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V2B Application to 20% of Buildings Suggests at Least 

1–2.5M 6-kW Capable Vehicles Could be Needed

73% (3.5M) are small commercial sites
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Value is Reasonable to Support Low-Cost 

Implementation Strategies
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Vehicle Grid Integration Research Summary

• VTIF and ESIF are unique facilities for the development 

and testing of Vehicle Grid Integration systems and 

strategies

• Vehicle-to-building integration (charge only and 

bidirectional) offer interesting value propositions with 

broad applicability and scales

o Need to address vehicle availability – able to leverage datasets

• DOE R&D efforts to address core questions:

o Quantify use cases, performance, and life impacts of grid 

applications

o Contribute to development of open interface standards

o Identify and quantify potential grid integration values