www.ecn.nl

Electric cars: part of the problem or a solution for future grids?

Frans Nieuwenhout, Energy research Centre of the Netherlands ECNSustainable Development: a challenge for European research, Conference,

Brussels, 26-28 May 2009

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Table of contents

• Introduction

• Electric cars and network infrastructure

• Active control of battery recharging

• Electric cars and the electricity system

• Some other issues

• Conclusion

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Introduction

Our future car: PHEV, EV or HFCV?

ICE

FC

E-motor

ICE: internal combustion engine; FC: fuel cell; HEV: hybrid-electric vehicle; PHEV: plug-in hybrid-electric vehicle; EV: electric vehicle; HFCV: hydrogen fuel cell vehicle

EV

HFCV

Hydrogen

(Green)electricity

(bio)fuel

Reduction of CO2 and local emissions

HEV PHEV

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Introduction

Contribution to the H2 – electricity debate

• This presentation will not:‑ Discuss which car-fuel combination is more sustainable‑ Which type of car wins the competition

• But will discuss the consequences of the PHEV and EV introduction on the electricity infrastructure

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Introduction

Electricity system and network infrastructure

Network infrastructure

Electric system

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Electric cars and the network infrastructure

LV grid

MVgrid Distribution

station

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Electric cars and the network infrastructure

Battery recharging

• Battery recharging options‑ At home or a parking place

‑ Slow charging (16A): 1-3 kW (230 V) up to 9 kW (400V)‑ Fast charging (40A): 9 kW (230 V) up to 27 kW (400V)

‑ At a filling station: fast charging and battery exchange

• Charging duration:‑ EV 40 kWh battery; 200 km driving range @ 160 Wh/km

‑ Slow: 6,7-40 hours‑ Fast: 2,5-4,5 hours

‑ PHEV 9 kWh battery; 50 km driving range @ 120 Wh/km‑ Slow: 4,5-9 hours‑ Fast: 0,5-1 hours

• Partial discharge (70-80%) due to lifetime considerations

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Electric cars and the network infrastructure

Available network capacity (I)Uncontrolled charging

[KV

A]

Maximum transport capacity

Daily patern households on MV level

Available remaining capacity

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Electric cars and the network infrastructure

Available network capacity (II)Uncontrolled charging

5 hours charging

[KV

A]

About 5 cars per 100 dwellings

Maximum transport capacity

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Electric cars and the network infrastructure

Available network capacity (III)Uncontrolled charging

5 hours charging

00:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00

[KV

A]

About 25 cars per 100 dwellings

Reinforcement of transport capacity

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Electric cars and the network infrastructure

Available network capacity (IV)Controlled charging

5 hours charging

[KV

A]

About 25 cars per 100 dwellings

Maximum transport capacity

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Electric cars and the network infrastructure

Available network capacity (V)Controlled charging

5 hours charging

[KV

A]

About 75 cars per 100 dwellings

Maximum transport capacity

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Active control

How to control recharging? (I)

•What should be known?‑ State of charge, i.e. how

empty is the battery?‑ Charging power (kW), i.e.

slow or fast charging‑ The driver’s preference, i.e.

when should the battery be fully recharged (within 1 hour, 4 hours, 8 hours etc.)

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Example: electric cars and the electricity system in Netherlands

What happens with 1 million electric cars (II)?

• 1 million electric cars• 20,000 km/year for each electric car• 5 km/kWh• 4000 kWh/year per car• 1 million x 4000 x 1.1 = 4,400,000,000 kWh = 4.4 TWh

• Dutch electricity consumption in 2008: 123 TWh

1 million electric cars will increase Dutch electricity demand with 3.6%1 million electric cars will increase Dutch electricity demand with 3.6%

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Electric cars and the electricity system

What happens with 1000,000 PHEVs or EVs? (II)

4.4 TWh / 365 = 12,000 MWh

Day with highest system peak load in 2005 and 2006

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Conventional: supply follows demandExtra peak and reserve capacity

Electric cars and the electricity system Electric cars can help to keep the energy balance

Conventional: supply follows demand

Intelligent demand and supply management results in less required extra peak and reserve capacity

Using flexibility fromthe demand side

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Hours/day

Days/year

Pric

e (E

uro/

MW

h)

APX Day-ahead electricity prices 2006

Electric cars and the electricity system Intelligent demand and supply management

prijs

Volume (MWh)

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No network constrain

Energy management

using market price

Constrained network

Local market operated within

network capacity limits

Electric cars and the electricity system Combined optimization

www.integral-eu.com

Comparable to local marginal

pricing (LMP)

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Electric cars and the electricity system Distributed storage

PHEV Prius: storage capacity 9 kWh2,2 million PHEV = 20 GWh

Controlled charging of PHEVs and EVs and other demand response can take care of fluctuating electricity supply

Controlled charging of PHEVs and EVs and other demand response can take care of fluctuating electricity supply

Tesla EV: storage capacity 60 kWh0,33 million EV = 20 GWh

Energy Island 20 GWh

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Some other issues

Recharging poles

• At home and in the street

• Cities try to stimulate EV with public recharging poles

•Who owns the recharging poles: network company or retailer?

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Some other issues

Vehicle to Grid (V2G)

LV grid

MVgrid Distribution

station

Micro CHP

Washing machineElectrical heatpump

PV panels

V2G: • to stabilize the network• in case of emergencies

V2G: • to stabilize the network• in case of emergencies

Alternative to V2G:

Stationarybattery

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Conclusions

• Electricity system and network infrastructure can handle large numbers of electric cars only if controlled charging is applied

• Controlled charging of large numbers of electric cars can help to handle supply peaks caused by wind and solar energy

Thank you!Thank you!