Nadia Maïzi
email: nadia.maizi@mines-paristech.fr

Matthieu Thiboust

Sandrine Selosse

Vincent Mazauric
email: vincent.mazauric@schneider-electric.com

Arbitrage between Energy Efficiency and Carbon Management in the Industry Sector: An Emerging vs. Developed Country Discrimination

Introduction

With the rise of energy prices and the development of carbon markets, Energy Efficiency and carbon emissions are two key decision variables for industrial actors. Those two variables are closely related, but the following question remains open: Does Energy Efficiency consist in the best allocation to reduce carbon emissions? This is not a general rule: if we consider, for instance, a nuclear power plant, it has a low carbon footprint but can be poorly efficient. The future development of Carbon Capture and Sequestration (CCS) technology will break even more this correlation. Thus, carbon management and energy efficiency management are different business models. The goal of this study is to evaluate the arbitrage between carbon management and energy efficiency implementation for industrial actors.

The study is organized as follow:

• In a first section the TIAM-FR model, which is a 15-region world version of the MARKAL/TIMES model family, is described. It is a bottom-up "Energy -Environment -Economy"-dedicated model which optimizes energy systems under constraints by using a partial equilibrium. This model is used for mid-term to long-term energy and carbon prospective (Loulou and Labriet, 2007;[START_REF] Loulou | TIMES Climate Module, IEA/OECD, ETSAP Documentation[END_REF].

• In order to compare energy efficiency and carbon policies, an extension giving access for each energy vector to:

• the primary equivalent and carbon content, along with • their evolution through time for each region, is implemented.

• Primary equivalent and carbon content of commodities will depend on various parameters (climate policies, processes availability, costs of technologies, demands, etc). Attention is paid on the definition of variant scenarios based on the COP15 pledges.

• Results are finally inspected in order to assess the arbitrage between energy efficiency and carbon management.

The TIMES formalism for energy modelling

With the research on energy modeling thriving, many different visions emerged, embodied in dozens of different modeling paradigms. They are often categorized in two major families, namely "bottom-up" and "top-down" models.

• The "top-down" models are said to be "economy-rich", and use economy and econometrics theory to derive evolution scenarios from a general equilibrium along with a set of macro-and microeconomics indicators (GDP, energy intensity, demography, growth effects, etc); • The "bottom-up" models are technology-rich models building general tendencies by piling up extremely disaggregated technology data (energy prices, investment costs, technology specific efficiencies), thus acting in a bottom-up way;

• The IAM (Integrated Assessment Models), which combine a top-down or bottom-up module with a climate or impact evaluation module, are a more all-inclusive (but often less precise) way to look at the problem.

The TIMES (The MarkAl-EFOM Integrated System) paradigm is a bottom-up representation, relying on highly disaggregated technology-rich data. It inherits the characteristics of two former modelling paradigms (MarkAl and EFOM), which had been developed from the early 80s to 2005 by the Energy Technology Systems Analysis Programme (ETSAP, 2007) under the aegis of International Energy Agency (IEA, 2006).

The analyses carried out in this work are derived from the ETSAP/TIAM-FR (the French version of the TIMES Integrated Assessment Model) bottom-up model developed by the Centre of Applied Mathematics of MINES ParisTech.

a. The ETSAP TIMES Integrated Assessment Model

TIAM-FR depicts the world energy system with a detailed description of different energy forms, resources, processes/technologies and end-uses. The link between the commodities and the technologies is described via a Reference Energy System (figure 1). More precisely, the RES is a network of interlinked commodities (an energy form, an emission, a material, or an energy service) and technologies (anything that produces and/or consumes commodities).

Figure 1. Simplified view of the Reference Energy System within the

• In the middle, a simplified representation codes used by TIMES modelers: the vertical lines are the energy carriers and the boxes are the technologies ( investment, operation and maintenance costs, its relationship between its inputs and its outputs. • In red boxes, the other constraints that the user must provide to complete the model;

• In green, the outputs of the calculations.

See Figure 2 for a synthetic representation of the Reference Energy System.

The main features are given below (Loulou and Labriet, 2007):

• TIAM-FR includes several thousand technologies in all sectors of the energy system (energy procuremen conversion, processing, transmission, and end investment and operation costs, description of the RES covering the whol extracted and in series number of steps, transformed into • In TIAM-FR, end-use demands ( specified exogenously by the user in physical units (number of houses, production, vehicle-kilometers, etc.) over the planning horizon. models, TIAM acknowledges that demands are endogenous variation of the demands in vast majority of the macroeconomic feedback of the energy system. Thereby, the energy consumption i TIAM-FR is based on external projections of the growth of regional GDP as well as population and of various economic sectors (transport, residential, industry, etc.). These drivers and given base year -in this case 2000 energy such as road passenger transportation, steel demand, residential heating, etc.

• TIAM-FR is a global multiregional model. It is geographically integrated and offers a representation of global energy system in 15 regions covering the entire world: Africa China (includes Hong Kong, excludes Soviet Union (includes the Baltic states), India -3- es are the technologies (processes in the TIMES language). Each process is described by its estment, operation and maintenance costs, its life, and its efficiency, thus defining a linear relationship between its inputs and its outputs.

, the other constraints that the user must provide to complete the model; he calculations. See Figure 2 for a synthetic representation of the Reference Energy System.

The main features are given below (Loulou and Labriet, 2007): FR includes several thousand technologies in all sectors of the energy system (energy procuremen conversion, processing, transmission, and end-uses). The description of the technologies includes data on efficiencies and, sometimes, market potentials. Figure description of the RES covering the whole energy chain. In order to satisfy the demands, energy sources are number of steps, transformed into the end-use demand commodities. use demands (i.e. energy services) are based on socio-economic assumptions and are specified exogenously by the user in physical units (number of houses, commercial area, industrial kilometers, etc.) over the planning horizon. However, contrary to traditional bottom models, TIAM acknowledges that demands are elastic to their own prices. This feature insures the endogenous variation of the demands in constrained runs (on emission or concentrations), thus capturing the macroeconomic feedback of the energy system. Thereby, the energy consumption i is based on external projections of the growth of regional GDP as well as population and of various economic sectors (transport, residential, industry, etc.). These drivers and IEA statistics for a in this case 2000 -are the basis for future projections of the consumption of different er transportation, steel demand, residential heating, etc. FR is a global multiregional model. It is geographically integrated and offers a representation of global energy system in 15 regions covering the entire world: Africa, Australia-New Zealand, Canada China (includes Hong Kong, excludes Chinese Taipei), Central and South America, Eastern Europe on (includes the Baltic states), India, Japan, Mexico, Middle-East (includes Turkey formalism framework:

for one demand, respecting the representation codes used by TIMES modelers: the vertical lines are the energy carriers (commodities), Each process is described by its life, and its efficiency, thus defining a linear , the other constraints that the user must provide to complete the model; FR includes several thousand technologies in all sectors of the energy system (energy procurement,

The description of the technologies includes data on Figure 2 gives a synthetic In order to satisfy the demands, energy sources are use demand commodities. assumptions and are commercial area, industrial However, contrary to traditional bottom-up ic to their own prices. This feature insures the constrained runs (on emission or concentrations), thus capturing the macroeconomic feedback of the energy system. Thereby, the energy consumption in is based on external projections of the growth of regional GDP as well as population and volume IEA statistics for a the consumption of different • 500 commodities;

• 15 regional areas.

The shadowed box denotes the altered part in order to implement Energy Efficiency potentials in the industry sector (see Figure 3). TIAM-FR is the global multiregional version of the TIMES model generator, a linear estimates an inter-temporal partial economic equilibrium on perfect markets and unlimited foresight for the commodities. In other words, the model minimizes, under environmental and technical constraints, the total discounted cost of the energy system energy system includes investment costs, operation and maintenance costs, costs of imported fuels, incomes exported fuels, the residual value of technologies at the end of the horizon, and welfare loss demand reductions. The model computes both the flows of commodities environmental), as well as their prices. The prices of the computed by the model, the suppliers of buy. The equilibrium feature is present at every stage of the energy system: primary energy forms, secondary energy forms, and energy services. TIAM simultaneously making decisions on equipment investment, equipment energy trade.

-4-Developing Asia (includes Chinese Taipei and Pacific Islands), South Korea, United States of America 15, Iceland, Malta, Norway and Switzerland). The regions are linked by energy, material, and emission permit trading variables, if desired. The trade variables transform the set of regional modules into a single multiregional (possibly global) energy model, where actions taken in one region may affect all other regions. This feature is essential when global as well as regional energy and emission

The model also consists of a number of other elements, such as user-defined constraints technology limitation and a climate module [START_REF] Loulou | TIMES Climate Module, IEA/OECD, ETSAP Documentation[END_REF].

Figure 2 . Global Reference Energy System, including more than:

The shadowed box denotes the altered part in order to implement Energy Efficiency potentials in the industry FR is the global multiregional version of the TIMES model generator, a linear programming model that temporal partial economic equilibrium on integrated energy markets. The model assumes esight for the calculation period, the described economic sectors, and model minimizes, under environmental and technical constraints, the total the energy system over the whole studied time horizon, typically 2000includes investment costs, operation and maintenance costs, costs of imported fuels, incomes exported fuels, the residual value of technologies at the end of the horizon, and welfare loss nd reductions. The model computes both the flows of commodities (energy forms, materials, and environmental), as well as their prices. The prices of the commodities are computed in such that at the prices computed by the model, the suppliers of energy produce exactly the amounts that the consumers are willing to feature is present at every stage of the energy system: primary energy forms, secondary energy forms, and energy services. TIAM-FR aims to supply energy services at minimum simultaneously making decisions on equipment investment, equipment operation, primary energy supply, and Pacific Islands), South Korea, United States of America and

The regions are linked by energy, material, and emission permit trading variables, if desired. The trade variables transform the set of regional modules into a single multiregional (possibly global) energy model, where actions taken in one region may is essential when global as well as regional energy and emission defined constraints, e.g. on emission or

:

The shadowed box denotes the altered part in order to implement Energy Efficiency potentials in the industry programming model that integrated energy markets. The model assumes calculation period, the described economic sectors, and model minimizes, under environmental and technical constraints, the total -2100. Cost of the includes investment costs, operation and maintenance costs, costs of imported fuels, incomes of exported fuels, the residual value of technologies at the end of the horizon, and welfare loss due to endogenous (energy forms, materials, and commodities are computed in such that at the prices uce exactly the amounts that the consumers are willing to feature is present at every stage of the energy system: primary energy forms, secondary global cost by operation, primary energy supply, and

The main outputs of the model are future investments and activities of technologies for each Furthermore, the structure of the energy system is given as an output, technologies, energy consumption by fuel, emissions, energy trade detailed energy system costs, and marginal model tracks emissions of CO 2 , CH 4 brought about by endogenous demand reductions, technology and fuel substitutions (leading to efficiency improvements and process changes in all sectors), carbon sequestration (including CO plant and hydrogen plant level, sequestration by forests, and storage in additional output of the model is the implicit price, or material and emission.

b. Energy Efficiency modelling

Generally, the percentage of Energy Efficiency energy and climate system. Aiming to consider arbitrage abatement solutions especially at the demand side (Renewables, Nuclear, Carbon Capture and Sequestration, Cleaner conventional power plants…), of the model.

Figure 3. Energy Efficiency disaggregation • Above: classical Energy Efficiency technology connecting input and output commodities;

• Below: disaggregation of the Figure 4.

Notice that the system has the possibility not to implement Energy Efficiency solution ( with other clean(er) generation technologies.

The basic idea would be to represent an Energy Efficiency technology as an energy service amplifier (figure 3), and modify the Reference Energy System characteristics.

However, the huge list of Energy Effici use of multiple commodities -could describing all of them appears to be homogeneous set of data or the risk of However, the purpose of this work is not to provide a sector Efficiency solutions in industry, but mitigation.

Hence, a cost/efficiency approach has been adopted (figure 3). It consists in disaggregating the energy efficiency potential in several steps (here refined to 20

-5-

The main outputs of the model are future investments and activities of technologies for each ucture of the energy system is given as an output, i.e. type and capacity of the energy technologies, energy consumption by fuel, emissions, energy trade flows between regions, transport capacities, a detailed energy system costs, and marginal costs of environmental measures as GHG reduction targets. The 4 , and N 2 O from fuel combustion and processes. Emission reduction is by endogenous demand reductions, technology and fuel substitutions (leading to efficiency improvements and process changes in all sectors), carbon sequestration (including CO 2 capture at the power plant and hydrogen plant level, sequestration by forests, and storage in oil/gas fields, oceans, aquifers, etc.) the implicit price, or opportunity cost (shadow price), of each energy form,

modelling in TIAM-FR

Energy Efficiency is an input in energy models, used for assessing Aiming to consider arbitrage between Energy Efficiency and other especially at the demand side (Renewables, Nuclear, Carbon Capture and Sequestration, Cleaner conventional power plants…), the optimal Energy Efficiency percentage need to be derived to represent an Energy Efficiency technology as an energy service amplifier the Reference Energy System (figure 2) according to its technical and economical Energy Efficiency-dedicated technologies involved in the industry sector could provide significant changes in the topology of the RES. appears to be huge, cumbersome and endless. Moreover, due to the lack of risk of double-counting, this approach could lead to a distorted model , the purpose of this work is not to provide a sectorial roadmap for short-term implementation of Energy industry, but to challenge the link between energy efficiency and carbon emission approach has been adopted (figure 3). It consists in disaggregating the energy efficiency potential in several steps (here refined to 20) with the following basics (figure 4):

The main outputs of the model are future investments and activities of technologies for each time period. and capacity of the energy flows between regions, transport capacities, a ironmental measures as GHG reduction targets. The O from fuel combustion and processes. Emission reduction is by endogenous demand reductions, technology and fuel substitutions (leading to efficiency apture at the power fields, oceans, aquifers, etc.) An opportunity cost (shadow price), of each energy form, implementation of Energy to challenge the link between energy efficiency and carbon emission approach has been adopted (figure 3). It consists in disaggregating the energy efficiency

• Each potential of Energy Efficiency checks a saturation level; • The residual potentials of Energy countries involved for a long time in EE policies

As a result, the cost curves were calibrated energy efficiency, and exponential step Energy Efficiency, the model has the possibility to determine the most cost Efficiency processes (i.e. the optimal percentage for a given region, a given secto competition with other clean(er) technologies mitigation pledges.

Figure 4. Regional Costs vs. Energy Efficiency potentials

Climatic scenarios for 2020

The international community appears to converge on its long emissions by 80% in 2050, compared to 1990 or 2005 depending the reference year adopted by the regions [START_REF] Remme | A global perspective to achieve a low-carbon society (LCS): scenario analysis with the ETSAP-TIAM model[END_REF][START_REF] Syri | Global energy and emissions scenarios for effective climate change mitigation -Deterministic and stochastic scenarios with the TIAM model[END_REF]

United States 2005

Western Europe 1990

A key feature of the post-Kyoto agreement was the participation of non and United States as they represent a large share of global C0

-6-Each potential of Energy Efficiency checks a saturation cap opening the possibility to implement the next nergy Efficiency are more expensive than the first steps. In other words, ountries involved for a long time in EE policies should implement more capital-intensive calibrated for different regions, according to their maturity exponential step-wise cost curves were adopted. With this aggregated implementation of , the model has the possibility to determine the most cost-effective allocation of E the optimal percentage for a given region, a given sector and a given year) clean(er) technologies, especially on the supply-side, in order to achieve carbon

. Regional Costs vs. Energy Efficiency potentials (relative scale)

Climatic scenarios for 2020-2030

The international community appears to converge on its long-term objectives, particularly to reduce GHG emissions by 80% in 2050, compared to 1990 or 2005 depending the reference year adopted by the regions [START_REF] Remme | A global perspective to achieve a low-carbon society (LCS): scenario analysis with the ETSAP-TIAM model[END_REF][START_REF] Syri | Global energy and emissions scenarios for effective climate change mitigation -Deterministic and stochastic scenarios with the TIAM model[END_REF]. In the mid-term, international negotiations occurring within the 1 countries, especially China, (Den [START_REF] Elzen | Reductions of greenhouse gas emissions in Annex I and non-Annex I countries for meeting concentration stabilisation targets. An editorial comment[END_REF]. Various kinds of pledges were expressed in COP15:

• While Europe and Japan pledge for a CO2 emission mitigation of respectively 20% and 25% to 2020, compared to 1990 level, other regions consider 2005 as reference year.

• A more pessimistic view was expressed by United States due to their late acceptation of a global mitigation process. Australia and Canada are expected to align themselves with the US commitment.

• For China, the commitment is not on the emission level but on the carbon intensity. This means that China's GDP will pursue its rise but carbon emissions will have to increase at a lower rate due to greater energy efficiency and investment in greener technologies.

An important and well-known observation to note concerns the choice of reference year. This induces of course an important impact on the target to reach. More precisely, if these pledges are translated on the same reference year, it means [START_REF] Selosse | Post-Kyoto policy implications on the energy system: A TIAM-FR long term planning exercise[END_REF]):

• For China, reducing CO2 by 40% to 2020 (resp. 80% to 2050) its carbon intensity compared to 2005 level is equivalent to limiting the increase of its CO2 emission at 292% in 2020 (resp. 485% to 2050) compared to 1990 level for its COP 15 pledge. Conversely, a pledge aiming to reduce its CO2 emission level by 10% to 2020 compared to 2005 level is equivalent to limit the increase of its CO2 emission at 109% in 2020 compared to 1990 level. Therefore, due to wide variation in GDP projections, it is obvious that China cannot reasonably pledge neither an emission reduction, nor 1990 as a base year. Indeed, the annual average growth rate of the China GDP for the period 2000-2050 is 6.37%, with a GDP which reaches US$30 000 billion in 2050.

• For the United States, reducing its CO 2 emission by 17% to 2020 (resp. 80% to 2050) compared to 2005 levels, is equivalent to reducing by 0.33% to 2020 (resp. 76% to 2050) its CO 2 emission compared to 1990 level. So, it appears clearly the lesser effort committed by United States in the mid-term, notably compared to the European Union, whereas they have emitted a larger share of CO 2 emissions. In other words, the United States are unlikely willing to pledge on a constrained short-term target, while they have ratified the agreement.

So, through the different targets, the level of commitments announced by the regions, particularly the lesser efforts of China and United States can be underlined.

To analyze possible alternative development paths of the system, a variety of environmental target scenarios on different regions of the world over the period 2000-2030 was investigated.

Reduction pledge

(with reference year)

Europe

USA China

COP15 -80%

more constrained by 20% than the COP15 scenario

COP15 -85%

more constrained by 15% than the COP15 scenario

COP15 -90%

more constrained by 10% than the COP15 scenario

COP15 -95%

COP15 -105%

less constrained by 5% than the COP15 scenario

COP15 -110%

less constrained by 10% than the COP15 scenario

COP15 -115%

less constrained by 15% than the COP15 scenario

COP15 -120%

less constrained by 20% than the COP15 scenario

COP15 -125%

less constrained by 25% than the COP15 scenario

COP15 -130%

less constrained by 30% than the COP15 scenario

Business As Usual

/ / /

A baseline Business As Usual (BAU) scenario without any emission constraints was first reference scenario, no climate policy and thus no post some key patterns in the evolution of the energy system, and served as the starting point for the analysis. Besides, eleven Carbon constraints scenarios investigating the changes induced by implementation of Energy Efficiency solutions within a competition with other abatement technologies.

In the following, the impact of these environmental measures on the energy system regions: Western Europe, USA and China.

Results

The variant scenarios are used to discuss the level of implementation of Energy Efficiency solutions in the industry sector under the climate-dedicated commitment. consider on the horizon are studied for the three constraint on the generation mix, the competiti Carbon Capture and Sequestration (CCS) technology is

a. Sensitivityof Energy Efficiency

A first set of graphs (Figure 5) represent the percentage of EE in 2020 in different industry sectors for different climate scenarios. Besides a lack of Energy Efficiency implementation within the BAU scenario • Energy Efficiency is increasingly used as carbon emissions becomes more • The development of Energy Efficiency and Europe than in China.

Figure 5. Sectorial s

This behaviour is also observed in term of cumulated energy efficiency market for the period 2010 6). Obviously, this trend is due to the lesser ambitious indicator on Carbon intensity adopted by the China. However, although Energy Efficiency solutions remain a power -8-sual (BAU) scenario without any emission constraints was first calculated. In the mate policy and thus no post-Kyoto policy are assumed. The BAU scenario outlined some key patterns in the evolution of the energy system, and served as the starting point for the analysis.

Carbon constraints scenarios centered on the COP15 pledges (hereabove table) the changes induced by stronger environmental policy, and determining the sensitivity of the implementation of Energy Efficiency solutions within a competition with other abatement technologies. the impact of these environmental measures on the energy system is analyzed s: Western Europe, USA and China. discuss the level of implementation of Energy Efficiency solutions in the dedicated commitment. Both sectorial analysis and global investment to consider on the horizon are studied for the three studied regions. To analyze the influence of the climatic he competition with the supply side is then investigated. A focus on the Carbon Capture and Sequestration (CCS) technology is finally given, as an example of decarbonized

Energy Efficiency policies to COP15 pledges

represent the percentage of EE in 2020 in different industry sectors for different Besides a lack of Energy Efficiency implementation within the BAU scenario is increasingly used as carbon emissions becomes more constrained fficiency solutions is more sensitive to carbon abatement pledges in the USA al sensitivity of Energy efficiency levels to COP15 pledges bserved in term of cumulated energy efficiency market for the period 2010 6). Obviously, this trend is due to the lesser ambitious indicator on Carbon intensity adopted by the China. However, although Energy Efficiency solutions remain a powerful lever to reduce CO 2 emissions in the industry calculated. In the assumed. The BAU scenario outlined some key patterns in the evolution of the energy system, and served as the starting point for the analysis.

(hereabove table), allowed stronger environmental policy, and determining the sensitivity of the implementation of Energy Efficiency solutions within a competition with other abatement technologies. bserved in term of cumulated energy efficiency market for the period 2010-2020 (figure 6). Obviously, this trend is due to the lesser ambitious indicator on Carbon intensity adopted by the China.

emissions in the industry sector, high-valued steps of Energy Efficiency (figure 4) appear less cost generation units for highly constrained scenarios. In other word, China provides opportunities to c supply-and demand-sides within the same carbon abatement framework. Conversely, for mature economical countries, the opportunity to implement generation capacities is very weak, and Energy Efficiency remains the only vector to achieve CO 2 emission mitigation.

b. Power generation mix

As a general result, constraints on carbon emissions compared to the BAU scenario (figure 7). However, the structure of the energy mix is changed for pledges more strict than COP15, whereas a weak sensitivity is observed for lower constrained scenarios • In China, the BAU structure is ke constraints on emissions; • In USA, the share of coal is progressively substituted by gas, nuke or renewable, from 40% for COP15 pledge to 20% for the strongest • In Europe, a coal substitution by nuclear, gas and geothermy the COP15-80% pledge.

c. Carbon Capture and Sequestration implementation

As is presented in figure 8, only more constrained pledges than COP15 lead Capture and sequestration technologies. higher level and earlier implementation subsequent to a longer implementation in the implementation is a marker of the stringency of the climate policy, following the exhaustion of the Energy Efficiency potential.

Conclusion

The implementation of the Energy Efficiency determine the optimal Energy Efficiency knowledge, it is the first time an aggregated approach of EE is depl this methodology (figure 4).

Because Energy Efficiency plays an important role in the fight against climate change, this promising approach is of key importance when studying the arbitrage betw In order to improve the relevance and the reliability of our model, further calibration work is especially to derive cost curves, and commercial, agriculture, oil & gas and electricity.

Let us note that the quite high investment levels in Energy Efficiency displayed by the model represent optimal economic potential, without any restrictions on the speed of the market penetration (industrial deploymen investment mechanism) or government incentives (subsidies, taxes…). This should be also considered influence a global Energy Efficiency policy.

-9-valued steps of Energy Efficiency (figure 4) appear less cost-effective in China than cleaner generation units for highly constrained scenarios. In other word, China provides opportunities to c sides within the same carbon abatement framework. Conversely, for mature economical countries, the opportunity to implement generation capacities is very weak, and Energy Efficiency remains the n mitigation.

. Sensitivityof the Energy Efficiency market to COP15 pledges Cumulated investment over the horizon 2010-2020 in Million US$

Power generation mix

constraints on carbon emissions have a limited effect on the global generation level (figure 7). However, the structure of the energy mix is changed for pledges more , whereas a weak sensitivity is observed for lower constrained scenarios:

In China, the BAU structure is kept till COP15 pledge. Hence, coal is partially replaced by gas for stronger In USA, the share of coal is progressively substituted by gas, nuke or renewable, from 40% for COP15 investigated scenario; In Europe, a coal substitution by nuclear, gas and geothermy is noticed; and a coal phase and Sequestration implementation more constrained pledges than COP15 lead to significant level of Capture and sequestration technologies. Even though CCS appears as a long term solution and earlier implementation in Europe reflects the saturation of Energy Efficiency potential to a longer implementation in the past, and a more ambitious commitment. Conversely implementation is a marker of the stringency of the climate policy, following the exhaustion of the Energy nergy Efficiency concept in the TIAM-FR energy model makes it possible to nergy Efficiency allocation for each region, each industrial sector and each year. To our knowledge, it is the first time an aggregated approach of EE is deployed in an optimization energy model plays an important role in the fight against climate change, this promising approach is of key importance when studying the arbitrage between carbon abatement solutions.

In order to improve the relevance and the reliability of our model, further calibration work is and the approach deserves to include other sectors like transport, residential, ure, oil & gas and electricity.

Let us note that the quite high investment levels in Energy Efficiency displayed by the model represent optimal economic potential, without any restrictions on the speed of the market penetration (industrial deploymen investment mechanism) or government incentives (subsidies, taxes…). This should be also considered a global Energy Efficiency policy.

effective in China than cleaner generation units for highly constrained scenarios. In other word, China provides opportunities to challenge sides within the same carbon abatement framework. Conversely, for mature economical countries, the opportunity to implement generation capacities is very weak, and Energy Efficiency remains the . Sensitivityof the Energy Efficiency market to COP15 pledges. generation level, (figure 7). However, the structure of the energy mix is changed for pledges more :

pt till COP15 pledge. Hence, coal is partially replaced by gas for stronger

In USA, the share of coal is progressively substituted by gas, nuke or renewable, from 40% for COP15

; and a coal phase-out is observed for to significant level of Carbon Even though CCS appears as a long term solution, its significantly the saturation of Energy Efficiency potentials, . Conversely, CCS implementation is a marker of the stringency of the climate policy, following the exhaustion of the Energy FR energy model makes it possible to allocation for each region, each industrial sector and each year. To our oyed in an optimization energy model within plays an important role in the fight against climate change, this promising approach

In order to improve the relevance and the reliability of our model, further calibration work is probably necessary, other sectors like transport, residential, Let us note that the quite high investment levels in Energy Efficiency displayed by the model represent optimal economic potential, without any restrictions on the speed of the market penetration (industrial deployment, investment mechanism) or government incentives (subsidies, taxes…). This should be also considered to

. Carbon Capture and Sequestration technology implementation.

lated level in 2030 is ten times higher than in 2020.

  TIMES formalism for energy modelling a. The ETSAP TIMES Integrated Assessment Model b. Energy Efficiency modelling in TIAM-FR 3. Climatic scenarios for 2020

Figure 1 .

 1 Figure 1. Simplified view of the Reference Energy System within the TIMES formalism frameworka simplified topology of the Reference Energy System for one demand representation codes used by TIMES modelers: the vertical lines are the energy carriers es are the technologies (processes in the TIMES language). Each process is described by its estment, operation and maintenance costs, its life, and its efficiency, thus defining a linear relationship between its inputs and its outputs.

FR

  Figure 2 . Global Reference Energy System,• 3,000 technologies;

Figure 3 .

 3 Figure 3. Energy Efficiency disaggregation for the industry sector. Above: classical Energy Efficiency technology connecting input and output commodities; Below: disaggregation of the Energy Efficiency potential in several steps. Cost curves are given in

  used for assessing its impact on the and other Carbon especially at the demand side (Renewables, Nuclear, Carbon Capture and Sequestration, need to be derived as an output for the industry sector. Above: classical Energy Efficiency technology connecting input and output commodities; Energy Efficiency potential in several steps. Cost curves are given in 0=1) in order to compete to represent an Energy Efficiency technology as an energy service amplifier, i.e. η>1 technical and economical dedicated technologies involved in the industry sector -and their significant changes in the topology of the RES. The task of the lack of a distorted model.

  ) Conference of the Parties (COP) under the auspices of the United Nations Framework Convention on Climate Change (UNFCCC), try to set up targets. The last attempt to fix global objectives occu Conference (COP15 in 2009).

  Conference of the Parties (COP) under the auspices of the United Nations Framework Convention on Climate try to set up targets. The last attempt to fix global objectives occurred in the Copenhagen agreement was the participation of non-Annex-1 countries, especially China, nited States as they represent a large share of global C0 2 emissions (Den Elzen and Höhne, 2008) opening the possibility to implement the next . In other words, intensive solutions. according to their maturity in experiencing aggregated implementation of effective allocation of Energy r and a given year) in a , in order to achieve carbon (relative scale). term objectives, particularly to reduce GHG emissions by 80% in 2050, compared to 1990 or 2005 depending the reference year adopted by the regions term, international negotiations occurring within the Conference of the Parties (COP) under the auspices of the United Nations Framework Convention on Climate rred in the Copenhagen

  is analyzed for the three discuss the level of implementation of Energy Efficiency solutions in the Both sectorial analysis and global investment to To analyze the influence of the climatic . A focus on the decarbonized technology. represent the percentage of EE in 2020 in different industry sectors for different Besides a lack of Energy Efficiency implementation within the BAU scenario: constrained; but more sensitive to carbon abatement pledges in the USA to COP15 pledges.

Figure 6 .

 6 Figure 6. Sensitivityof the Energy Efficiency market to COP15 pledgesCumulated investment over the horizon 2010

Figure 7 .

 7 Figure 7. Power generation mix.

Figure 8 .

 8 Figure 8. Carbon Capture and Sequestration technology implementatioNotice the cum

Acknowledgements

This research was supported by the Chair Modeling for sustainable development, driven by MINES ParisTech, Ecole des Ponts ParisTech, AgroParisTech, and ParisTech; and supported by ADEME, EDF, GRT gaz and SCHNEIDER ELECTRIC.