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ENERGY TRANSITION TOWARD RENEWABLES AND
METAL DEPLETION: AN APPROACH THROUGH THE
EROI CONCEPT
Florian FIZAINE* et Victor COURT**
*LEDi - Laboratoire d'Économie de Dijon - UMR 6307 - Université de Bourgogne, Email : [email protected]
**EconomiX - UMR 7235 - Université Paris Ouest, Nanterre - La Défense, Email : [email protected]
Seminar of presentation of student’s papers
Annual French AEE Conference, 24-25 November, 2014
Outline
I. Introduction and context
II. Empirical observations
III. Methodology
IV. Results
V. Discussion
VI. Conclusion
2
I. Introduction and context (1/3)
For many researchers (Stern and Kander (Energy Journal, 2012); Ayres
and Voudouris (Energy Policy, 2014)) economic growth depends mostly
on three productive factors: labor, capital and energy.
Far from being perfect substitutes, these factors are probably
complementary which implies for these same authors that GDP
growth is mainly driven by energy consumption growth.
World energy consumption mostly comes from fossil fuels.
Tackling climate change implies to emit less GHG.
Energy efficiency and renewable energy technologies appear as the best
solutions to adress both problems at the same time.
3
I. Introduction and context (3/3)
Limited research has been done on the dynamic between energy and metal sectors (Harmsen et al., 2013).
Extracting metals comes at an energy cost.
Despite technological progress, increasing energy cost of extraction is a consequence of ore grade degradation associated with metal depletion.
This necessarily impacts the ability of an energy system to deliver net energy.
Research question: How is metal ore grade evolution affecting the EROI of renewable technologies ?
5
II. Empirical observations (1/3)
Our calculations show that 10% of global primary energy is consumed by the metal sector.
Difficult to generalize the counter calculation, although Bihouix and De Guillebon (2010) have estimated that 5 to 10% of steel production is used by the energy sector.
Data from the IEA are interesting to observe such dynamic aspects.
6
Evolution of the final energy consumption of different sectors (based 100
in 1973). Source: IEA, 2014.
II. Empirical observations (2/3)
Ore grade degradation is observable at different levels: deposit (Crowson,
2012), country (Mudd, 2010) and world(Crowson, 2012 ; Schodde, 2010).
Source : Crowson (2012)
7
II. Empirical observations (2/3)
Source : Schodde (2010)
8
Ore grade degradation is observable at different levels: deposit (Crowson,
2012), country (Mudd, 2010) and world(Crowson, 2012 ; Schodde, 2010).
II. Empirical observations (3/3)
We have extended the work
of Norgate and Jahanshahi
(2010) in order to determine
an econometric relation
between ore grade (X) and
energy cost of extraction (Y).
Y = 279.25*X-α
With best estimate for α=-
0.6OO26 and a 95%
confidence interval of (-
0.418609; -0.781910)
9
y = 279.25*X-0.6 R² = 0.58606
y = 77.585*X-0.857 R² = 0.99603
1,000
10,000
100,000
1000,000
10000,000
100000,000
1000000,000
0,0001 0,0010 0,0100 0,1000 1,0000 10,0000 100,0000
Ene
rgy
con
sum
pti
on
fo
r o
ne
me
tric
to
n (
GJ/
t)
Minimum ore grade
Calibrated on 34 metals Norgate and Jahanshahi (2010)
The Energy Return On Investment (EROI) is a pertinent indicator of the accessibility of the energy:
Energy Out:
Energy extracted from the
environment Energy In:
Direct and indirect energy
invested in the energy system
Some facts
Fossil fuels present declining EROI with maximum EROI already passed (Hall
et al., 2014).
Renewable technologies have very different EROI: from 2 in the case of
biofuels, to 20 for wind power and value superior to 50 for hydropower
installations.
In each technology, metals account for a specific share of the energy
invested
10
III. Methodology: EROI concept
14
IV. Results: EROI sensibility to copper ore grade
degradation (general vs. specific relation)
0
10
20
30
40
50
60
0
5
10
15
20
25
0,001% 0,010% 0,100% 1,000% 10,000%
Hydro EROI Other EROI
Grade of copper
Parabolic Trough
Solar Tower Plant
PV Single Si
PV Multi Si
PV a Si
PV CIGS
PV CdTe
Onshore Wind Power
Offshore Wind Power
Nuclear Power (PWR)
Hydropower
Sensibility of the EROI of different energy
technologies to the grade of copper
specific copper relationship:
consumption=1.397*grade^-0.857
Sensibility of the EROI of different energy
technologies to the grade of copper
general econometric relationship :
consumption=5.446*grade^-0.60026
0
10
20
30
40
50
60
0
5
10
15
20
25
0,001% 0,010% 0,100% 1,000% 10,000%
Hydro
EROI
Other
EROI
Grade of copper
Parabolic Trough
Solar Tower Plant
PV Single Si
PV Multi Si
PV a Si
PV CIGS
PV CdTe
Onshore Wind Power
Offshore Wind Power
Nuclear Power (PWR)
Hydropower
15
IV. Results: EROI sensibility to nickel and
chromium ore grade degradation
Sensibility of the EROI of different energy
technologies to the grade of nickel
specific copper relationship:
consumption=11.463*grade^-0.60026
Sensibility of the EROI of different energy
technologies to the grade of chromium
general econometric relationship :
consumption=26.529*grade^-0.60026
0
10
20
30
40
50
60
0
5
10
15
20
25
0,001% 0,010% 0,100% 1,000%
Hydro
EROI
Other
EROI
Grade of nickel
Parabolic Trough
Solar Tower Plant
PV Single Si
PV Multi Si
PV a Si
PV CIGS
PV CdTe
Onshore Wind Power
Offshore Wind Power
Nuclear Power (PWR)
Hydropower
0
10
20
30
40
50
60
0
5
10
15
20
25
0,001% 0,010% 0,100% 1,000% 10,000%
Hydro
EROI
Other
EROI
Grade of Chromium
Parabolic Trough
Solar Tower Plant
PV Single Si
PV Multi Si
PV a Si
PV CIGS
PV CdTe
Onshore Wind Power
Offshore Wind Power
Nuclear Power (PWR)
Hydropower
16
IV. Results: EROI general sensibility to the
depletion of all metals
Evolution of the EROI of different energy
technologies to a similar degradation (θ) of the
grade of all geochemically rare metals. A multiple
of the current grade of 0.1 means that current
grades of all geochemically rare metals are divided
by a factor of 10.
Relationship: μ=θα, where α=0.60026
Relationship: μ=θα, where α=0.781910
0
10
20
30
40
50
60
0
5
10
15
20
25
0,001 0,01 0,1 1
Hydro
EROI
Other
EROI
Multiple of the current grade
Parabolic Trough
Solar Tower Plant
PV Single Si
PV Multi Si
PV a Si
PV CIGS
PV CdTe
Onshore Wind Power
Offshore Wind Power
Nuclear Power (PWR)
Hydropower
0
10
20
30
40
50
60
0
5
10
15
20
25
0,001 0,01 0,1 1
Hydro
EROI
Other
EROI
Multiple of the current grade
Parabolic Trough
Solar Tower Plant
PV Single Si
PV Multi Si
PV a Si
PV CIGS
PV CdTe
Onshore Wind Power
Offshore Wind Power
Nuclear Power (PWR)
Hydropower
18
V. Discussion
Enhancing effects not taken into account The « Mineralogical Barrier » of B.J Skinner (1976)
Further decreasing return in future deposits: deeper, more impurities. (UNEP, 2013)
Consideration of other externalities: environmental impacts from waste management, water need, GHG emissions, etc.
Energy cost associated with the construction and maintenance of other parts of the energy system: grid, storage systems. (Harmsen et al.)
Mitigating effects not taken into account Recycling
Decreasing material intensity of technologies
Energy efficiency gains
Technical substitution of rare metals with common metals
Energy economies of scope through coproduction
Energy economies of scale
VI. Conclusion
19
Focusing on « quality depletion » is even more important than
« quantity depletion ».
Inter-sectoral approach is helpful to apprehend complex problems
without reporting issues on others sectors.
The energy transition as we conceptualize it nowadays may not lead
us to energy sustainaility as we would report the depletion problem
from fossil fuels to metals (in particular « geologicaly rare metals »).
Even if technological progress will be effective in some areas, a
simpler answer might be to bring some rationality in our way of life.
Appendix: metal intensity
21
Parabolic trough
Solar tower plant
PV single si
PV multi si PV a Si
PV CIGS PV CdTe
Onshore wind Offshore wind
0
1
2
3
4
5
6
Cad
miu
m
Ch
rom
ium
Co
pp
er
Gal
ium
Ind
ium
Lead
Mo
lyb
den
um
Nic
kel
Nio
biu
m
Sele
niu
m
Silv
er
Telu
riu
m
Tin
Van
adiu
m
Zin
c
Pra
seo
dym
ium
Neo
dym
ium
Terb
ium
Dys
pro
siu
m
Metal intensity (t/MW)
Appendix: Pourquoi une approche par l’énergie ?
Il existe principalement deux approches pour mesurer l’épuisement : l’approche
monétaire de l’école néoclassique et l’approche énergétique de l’école biophysique.
Les prix de marché des énergies souffrent d’un certain nombre d’inconvénients (Hall et al.,
2009) :
Les prix sont influencés par des variables et des conditions actuelles (géopolitiques,
politiques économiques, monétaires, taux de change…) indépendantes du niveau
d’épuisement.
Ils n’intègrent pas les externalités et incorporent la plupart du temps des biais dus aux
subventions.
Leur extrême volatilité en font des indicateurs de très faible qualité pour anticiper l’avenir.
S’ajoute aussi l’ensemble des problèmes de mesures temporelles et spatiales de la monnaie
(choix du déflateur, biais divers…).
C’est pourquoi nous optons pour une approche énergétique de la valeur.
22
Appendix: theoric minimum energy
23
Source : World Steel Association
Source : US DOE (2007)
Minimum énergétique théorique
5,99 kWh/kg
Minimum énergétique théorique
5,37 M BTU/tonne
25
Appendix: Clark Value vs. Energy Factor
y = x0.6
y = x0.857
0
500
1000
1500
2000
2500
3000
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
Mu
ltip
lyin
g fa
cto
r af
fect
ing
un
itar
y e
ne
rgy
con
sum
pti
on
Clarke Value
Calibrated on 34 metals Calibrated on data of Norgate and Jahanshahi (2010)
Appendix :Effect of recycling
28
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
0,00001% 0,00010% 0,00100% 0,01000% 0,10000% 1,00000% 10,00000% 100,00000%
ER
OI
Ore grade for copper (primary production)
Recycling content = 0% Recycling Content 50%
Recycling Content = 30% Recycling Content Content 99%
Technology: PV CadTe, Exhaustion of copper
Recycling Content:
Quantity of secondary copper in
the total flow of copper required
Different from end of life recycling
rate