Plug-in hybrids - panacea or placebo? - Dr. William Smith
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Plug-in hybrids –
panacea or placebo?
Dr. William Smith
UCD School of Electrical, Electronic &
Mechanical Engineering
17th April 2009
Earth Systems Institute Institiúid na gCóras Domhanda
University College Dublin An Coláiste Ollscoile Baile Átha Cliath
Email: esi.admin@ucd.ie Web: www.ucd.ie/earth
Key UCD Message • The Innovation Imperative: Productivity growth in the Irish economy has slowed to close to zero. The only way to rediscover productivity growth and be able to sustain it is by innovation and the embedding of the knowledge society. • The Energy and Climate Change Imperative: We have hugely demanding energy and emission reduction obligations – the only way to meet them is through the use of markets and innovation. • The Earth Systems Institute response to these imperatives - We will be an engine showing how to use research and innovation – smart technology and smart policy - to regain competitiveness and productivity generate jobs and meet our energy and productivity, climate change obligations
Personal transport is good…
Freedom
Flexibility
Functionality
…but it’s Carbon-intensive, and oil-dependent
We need to reduce oil dependence
Source: BP Statistical Review of World Energy 2008
We need to reduce oil dependence
Annual Production Scenarios with 2 Percent Growth Rates and
Different Resource Levels (Decline R/P = 10)
70
USGS E
Estimates
ti t off Ultimate
Ulti t Recovery
R 2047
60 Ultimate Recovery
Probability BBls 2%
2037
-------------------- --------- Growth
ear
50 Low (95 %) 2,248
2 248
Barrels per Ye
Mean (expected value) 3,003
2026
High (5 %) 3,896
40
Decline
R/P = 10
Billion B
30
History
20
Mean
Low (95 %)
10 High (5 %)
0
1900 1925 1950 1975 2000 2025 2050 2075 2100 2125
Note: U.S. volumes were added to the USGS foreign volumes to obtain world totals.
Source: EIA, 2000
We need to reduce GHG emissions
60
ons (Mt CO2eq)
50
0
Ireland’s target
(allowing for
Carbon sinks)
40
2.7 Mt
GHG emissio
30 Transport
Annuall non-ETS G
Other
20 Agriculture
10
0
2007 2020 (with all Policy 2020 (all Policy +
measures) Economic shock)
Source: EPA GHG emissions projections 2009
The question is...
Road transport is currently 100% dependent on oil
¾ Insecure
¾ Carbon-intensive
C b i t i
Electricity is heading towards 40% contribution from renewables
¾ More secure supply
¾ Carbon-free
Electrification of road transport might tackle both issues – but is it
a panacea,
pa acea, or a placebo?
o p acebo
Outline of presentation ¾ What is a plug-in hybrid (PHEV)? ¾ The impact of drive cycle on electric vehicle (EV) performance ¾ Advantages and constraints of operation in EV mode ¾ How quickly might PHEV penetrate the passenger car fleet? ¾ How much benefit can PHEV deliver?
What is a Plug-in Hybrid?
CV
EV
engine
High efficiency (STW)
motor
No tailpipe emissions
fuel
battery
Poor performance
Short rangeWhat is a Plug-in Hybrid? HEV PHEV motor motor battery battery engine engine fuel fuel
What benefits accrue from electric (EV) mode?
Electric power limit
• Regenerative braking
ping power
Rear brakes
¾ Power capability of electrical system
¾ Only driven wheels
Stopp
Front brakes
¾ Some electrical losses
Regenerative braking
Brake pedal pressure
• No idling
• Electric motor more efficient than
petrol or diesel – especially at low
vehicle speeds, or from cold start.What benefits accrue from electric (EV) mode?
So EV is much more efficient (STW), for drive cycles with:
¾ low vehicle speeds urban / suburban
¾ a lot of gentle braking hilly
smooth driving style
¾ a lot of idling
Conversely, small or zero benefits accrue on trips with:
¾ high vehicle speeds
motorway
¾ little gentle braking
abrupt driving style
g
¾ little idlingWhat does the “Irish” drive cycle look like?
Nobody knows
Other
O e countries?
cou es
¾ NEDC – EU, certification only
¾ ARTEMIS – EU,
EU “real
real world”
world
¾ US06 – US, “real world”
UCD is now active in this area:
¾ UEP (EPA)
www.uep.ie
¾ ETASCI (EPA)
¾ Vehicle modelling
modelling, d
drive
i eccycle
cle anal
analysis
sisUCD study of the “Irish” drive cycle Instrumented vehicles – GPS + OBDII SCATS data Route analysis (POWCAR) ¾ Time of day ¾ Day of week ¾ Week of year Vehicle modelling
UCD study of the “Irish” drive cycle
• Give example of Ed Casey’s Drumcondra run:
• Google earth
Dublin Airport
• Overlay trace of route
• Show speed-time
speed time trace – highlight
Extra-urban
idle
idle, braking,
braking
5 minutes
Vmax
• Contrast with speed-time trace for ARTEMIS motorway
• Compare Wh.km -1 for EV and CV (assuming EREV)
Urban
12 minutesUCD study of the “Irish” drive cycle
120
100
Dublin
80
h-1)
speed (km.h
60
vehicle s
40
20
0
0 200 400 600 800 1000 1200
Time (s)Compare with the EU certification drive cycle
120
100
Dublin Similar speeds
80
Less steady
60
hicle speed (km.h-1)
40
More abrupt
20
0
120
Veh
100
NEDC
80
60
40
20
0
0 200 400 600 800 1000 1200
Time (s)EU ARTEMIS programme
140
120
100
motorway
h-1)
speed (km.h
80 urban
b
60
s
40
20
0
0 200 400 600 800 1000 1200
time (s)What energy is required by CV for these cycles?
1000
VW Golf 5-door, 2.0 TDI
thermodynamic losses
900 mechanical losses
idling loss
800
equirementt (Wh.km-1)
braking loss
minimum needed
Factor of 2
700
Lower out of town
600
500
400
Energy re
300
200
100
0
ARTEMIS NEDC urban Dublin US06 NEDC ARTEMIS NEDC extra-
urban combined motorway 130 urban
UCD drive cycle modelWhat benefits accrue from electric (EV) mode?
1000
Assume: 60% regeneration efficiency, 75% STW efficiency
900 socket to wheel losses
800
equirementt (Wh.km-1)
minimum needed
700
600
500
400
Wall socket energy
gy
→ 5 – 12 km
km.kWh
kWh-11
Energy re
requirement
300
200
100
}
0
ARTEMIS NEDC urban Dublin US06 NEDC ARTEMIS NEDC extra-
urban combined motorway 130 urban
UCD drive cycle modelWhat benefits accrue from electric (EV) mode?
1000
Assume: 60% regeneration efficiency, 75% STW efficiency, 45% generation efficiency
900 thermodynamic losses
socket to wheel losses
800
equirementt (Wh.km-1)
minimum needed
700
600
500 Higher out of town
400
Factor of 2.5
25
Energy re
300
200
100
0
ARTEMIS NEDC urban Dublin US06 NEDC ARTEMIS NEDC extra-
urban combined motorway 130 urban
UCD drive cycle modelPrimary energy required: CV versus EV mode
3.5
conventional
km-1)
3.0 EV mode
ement (MJ.k
EV mode 2010
2.5
ergy require
2.0
1.5
Primary ene
1.0
05
0.5
P
0.0
ARTEMIS NEDC urban Dublin US06 NEDC ARTEMIS NEDC extra-
urban combined motorway 130 urban
Big savings per km Big kmWhat about CO2?
• Operating in electric (EV) mode, PHEV require ~ 80–200 Wh of
domestic electricity per km travelled – say 140 Wh.km-1
• In 2007, the CO2 emissions associated with electricity were
543 g
g.kWh-1, including
g losses. ((SEI,, Energy
gy in Ireland 1990-2007))
• CO2 emissions for operation in EV mode therefore, amount to:
543 g.Wh-1 x 140 Wh.km-1 = 76 g.km-1
1000
• In 2007, CO2 emissions from new Irish passenger cars
averaged ~163 g.km-1 on the NEDC. (ibid)
• Estimated CO2 emissions for buses in GDA:
~67 g.p-1.km-1 (UCD calculations)What about CO2 in the future?
Fleet-average NEDC CO2 emissions (g.km-1) 200
180
160
CV
140
130 g.km-1
EV
120
EU limits for new cars
100 95 g.km-1
-17%
80
-45%
60
40
Note: Improvements in electrical generation efficiency propagate
20 instantaneously through EV fleet
0
2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032
YearInterim summary 1
Operating in electric (EV) mode, PHEV can:
¾ reduce primary energy requirement by
~ 75% during urban driving
~ 20-25% during extra-urban and motorway driving
¾ eliminate oil-dependence of passenger cars
¾ reduce CO2 emissions by 50-60%
¾ eliminate tailpipe emissions
...so why not full EV?So why not full EV (BEV)? Li-ion technologies are emerging as clear leaders for PHEV
So why not full EV (BEV)? Li-ion technologies are emerging as clear leaders for PHEV
How big is the battery?
D
Depends
d on desired
d i d range, drive
d i cycle
l
Advanced battery storage: energy equivalent to
50 litres of petrolHow big is the battery?
D
Depends
d on desired
d i d range, drive
d i cycle
l
Advanced battery storage with energy equivalent to
1 litre of petrol: 30-80 km AERHow much does the battery weigh?
1000
soline equiivalent
900
800
700
kg of battery per litre of gas
600
500
400
300
200
100
0
lead-acid NiMh Li-ion gasolineHow much does the battery weigh?
Strong trade-off between energy and powerHow much does the battery cost?
Cost of energy storage ~ € 2 (gasoline)
(per litre of gasoline)
€ 6,000 (NiMh)
€ 7,500 (Li-ion)
€ 2,500 (Li-ion target)
Cost reductions expected to come from:
• Technological development
• Economies of scaleSome current and imminent PHEV
G
Generally
ll classified
l ifi d b
by “All
“All-Electric
El t i R Range”” (AER)
(AER):
¾ PHEV-10 = 10 miles (or km!) of AER
¾ PHEV-50
PHEV 50 = 50 miles of AER etc.
etc
depends on characteristics of driving cycle
New Prius III is a PHEV-7*:
• NiMh battery
• limited capability in EV mode
GM Volt (Opel Ampera) is a PHEV-40:
• Li-ion
Li i b tt
battery
• full capability in EV modeInterim summary 2
For a pure EV (BEV):
¾ performance is limited by electrical power capability
¾ range is severely limited (range anxiety)
¾ recharge rates are slow(ish)
¾ cost off battery
b pack
k is
i high
hi h
¾ substantial packaging and weight penalties
For a PHEV:
¾ range anxiety is eliminated
¾ performance, cost, packaging and weight
impacts are mitigated
¾ more flexible solutionHow quickly might PHEV penetrate the fleet?
Use very simplified model:
¾ Assume classic logistic growth curve
¾ Allow sales to commence in 2011
¾ Posit three
th ee sales scenarios:
scena ios
¾ rapid – 50% market share achieved in 7 years
¾ moderate – 50% market share in 11 years
¾ slow – 50% market share in 15 yearsPHEV sales penetration – scenarios
100%
rapid sales
90%
et penetration
80% moderate sales
70%
slow sales
PHEV market share, flee
60%
Chrysler estimate for US
50%
40%
30%
20%
0%
10%
0%
2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034
YearPHEV fleet penetration – scenarios
Assumes fleet size fixed, complete turnover every 12 years
100%
rapid sales
90%
et penetration
fleet, rapid
80%
fleet, moderate
70%
fleet, slow
PHEV market share, flee
60%
5-6 years
50%
40% Switzerland,
S l d Sweden,
S d
US, 1.5m PHEV 15% plug-in
30%
Ireland, 10% plug-in
20%
0%
Germany, 10m plug-in
10%
Germany, 1m plug-in
0%
2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034
YearHow many PCkm are completed in EV mode?
Again use very simplified model:
Again,
¾ Estimate trip-distance distribution (POWCAR)
¾ Assume full performance capability in EV mode
¾ Assume one (overnight) charge per 24-hour period
¾ Calculate
C l l t percentage
t off PCkm
PCk th
thatt could
ld b
be completed
l t d in
i EV
mode, as a function of all-electric rangeAnalysis of 2006 POWCAR data
Accounts for only 30% of total PCkm
work-km 100%
90%
cumulative fractiion of PC work trips, w
80%
70%
POWCAR 2006 work trips
60% POWCAR 2006 work‐km
50%
40%
30%
20%
0%
10%
0%
0 20 40 60 80 100 120
Distance travelled to work as PC driver (km)PHEVkm completed in EV mode
Assumes 1 charge per 24h period (overnight at home)
EVkm completed in EV mode 100%
90%
80%
70%
Also assumes full performance capability in EV mode
60%
50%
40%
ction of PHE
30%
20%
Frac
10%
0%
0 20 40 60 80 100 120
PHEV all-electric range (km)PCkm in EV mode – scenarios
100%
rapid sales, AER = 80 km
90%
moderate sales, AER = 80 km
Fraction of all PCkm in EV mode
e
80%
slow sales, AER = 15 km
70%
60%
50% Equivalent to reduction in
oil requirement for PC,
solely due to PHEV
40%
30%
20%
0%
10%
0%
2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034
YearPrivate car CO2 emissions – moderate scenario
9,000
PCkm increase 1% per annum
2006 technology
improved CV
8,000
improved CV + PHEV
all
ll EV
7,000
ons (kt)
6,000 30%
Irish PC CO2 emissio
64%
5,000
4,000
3,000
2,000
1,000
0
2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032
YearCO2 savings from PHEV – to 2020
PCkm increase 1% p
per annum
1,600
1,400 1,350 kt
m PHEV (ktt)
1,200
1,000
,
savings from
800 re 2006 CV
re improved CV
nnual CO2 s
600
400
259 kt
An
200
0
2006 2008 2010 2012 2014 2016 2018 2020 2022
YearCO2 savings from PHEV – to 2030
PCkm increase 1% p
per annum
4,000
3,500 3.43 Mt
m PHEV (kt)
3,000
2,500
,
savings from
re 2006 CV
re improved CV
2,000
1 48 Mt
1.48
nnual CO2 s
1,500
1,000
An
500
0
2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032
YearContribution of PC to TPER
Private cars are responsible
p for < 15% of national Total Primary
y Energy
gy Requirement
q (TPER)
( )
16%
14%
PER due to private cars
s
12%
10%
8%
action of TP
6%
4%
Fra
2%
0%
1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
YearPHEV – impact on electricity demand
al demand ((TWh) 50
45
40
35
ual electrica
30
25
rapid sales, AER = 80 km
20
Projjected annu
moderate sales, AER = 80 km
Slow sales, AER = 15 km
15
No EVkm
10
5
0
2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034
YearPlug-in hybrids: panacea or placebo?
Based on the foregoing analyses:
¾ For the foreseeable future, each km travelled in EV mode will
reduce CO2 emissions and PER of Irish PC by
y 20%-50%.
¾ Collateral reductions in other tailpipe emissions, and in oil-
dependence are substantial and highly beneficial.
dependence, beneficial
¾ The benefits postulated here require little or no infrastructural
investment, at least in the short term.
¾ Due to the need to turn over the existing PC fleet, the impact
of PHEV will be modest to 2020, but may grow rapidly
thereafter.Plug-in hybrids: panacea or placebo?
Notwithstanding these benefits,
benefits however:
¾ Passenger cars are responsible for < 15% of national PER,
and < 8% of national GHG emissions.
¾ Hence, even dramatic reductions in the PER and GHG
emissions of the PC fleet,
fleet will deliver relatively modest gains
at a national level.
¾ Limitations of battery technology preclude a wholesale
transition to BEV; PHEV offer an excellent compromise for PC,
but electrification of road freight remains challenging.UCD Earth Systems Institute
Meeting the Challenge of Climate Change
Seminar Series
In collaboration with
Comhar Sustainable Development Council, Environmental
Protection Agency, Forfás, Geological Survey of Ireland,
Marine Institute, Met Éireann, Sustainable Energy
Ireland & Teagasc
Further details on the seminar series is available at www.ucd.ie/earth
A paper and podcast of this seminar will be available on the ESI website
soon, please join the online ESI mailing list for such notifications
ESI email: esi.admin@ucd.ieUCD Earth Systems Institute
Meeting the Challenge of Climate Change
Seminar Series
Next week...Seminar #17
Friday 24th April 2009
Royal College of Physicians, 12.30pm
Professor Eugene
g O’Brien
UCD School of Architecture, Landscape & Civil Engineering
Long distance road freight – growing at
unsustainable levels
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