How to prioritise which energy efficiency indicators to develop? Emer Dennehy

How to prioritise which energy efficiency
indicators to develop?
Emer Dennehy
Energy Analyst (Energy Efficiency
Indicators)
Energy Technology Policy Division
© OECD/IEA 2014
What is an indicator?
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What is an energy efficiency
indicator?
energy efficiency
indicator (EEI)
energy consumption
activity
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Why are energy efficiency
indicators important?
 Understand how energy is used
Understand the main factors
influencing trends in energy use
Evaluate the role of energy efficiency
to restrain growth in energy
consumption
 Evaluate the impact of existing and
future energy efficiency policies and
programmes
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How are energy efficiency indicators
used?
In IEA analysis energy efficiency indicators
link with scenarios, technology and policy
High-level engagement
Develop more
detailed
indicators
Evaluate
progress on
energy
efficiency
recommendations
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Indicators
Scenarios
Policy
Technology
Enhance
regional /
technology
detail
Sector
roadmap
development
National
roadmap
Overview of IEA Energy Efficiency
Indicators Work
 Establish a harmonised framework for data
collection and analysis
 Harmonisation => Comparability
 Comparability => Understanding of global trends and
drivers
 Produce meaningful cross-country analysis
to provide guidance to policy-makers on:
 Underlying drivers (economic activity &
structure, income, prices...)
 Trends in energy use and CO2 emissions
 Energy efficiency opportunities and progress
 Policy effectiveness
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IEA Energy Efficiency Indicators
Pyramidal Approach
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Energy Efficiency Indicator Manuals
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Energy Efficiency Indicators: Essentials
 What are the basic indicators & how to
prioritise development of indicators?
 What key insights do indicators provide
into trends driving energy use?
 How can these indicators be used to
quantify energy efficiency and track
policy impacts?
 Discusses what additional data and
indicators are required for more robust
analysis and cross country comparisons
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Essentials sector chapter structure
 What is driving energy use?
 How is energy being used and how has it
evolved recently?
 What sector / sub-sector / end use /
technology / process should be prioritised?
 Develop indicators by level of the pyramid
 Additional indicators
 Decomposition analysis
 Policy information and evaluation
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How to get started?
 What is the most energy consuming sectors?
 What is the faster growing sector?
 Analyse
 By total energy or by fuel
 What is the data availability?
 What level of disaggregation is available?
 What level of disaggregation is required?
 What indicator is most relevant for policy
development?
 What indicators are useful for cross-country
comparisons?
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Why is a pyramid used to describe EEIs?
 Emphasise that the more data available the
more meaning indicators can be calculated
 Level 1
 Sector or total fuel consumption
 Level 2
 Sub-sector or end use
 Level 3
 Process of technology
 Beyond level 3
 Depends on data availabilty
 Additional indicators
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Level 1 indicators: Residential
Example
Indicator
Residential energy
consumption per
capita
Residential energy
consumption per
occupied dwelling
Data required

Total residential
energy
consumption by
energy source.

Population.

Energy
consumption.

Number of
occupied
dwellings.
Purpose

Can be constructed for many
countries and provides a consistent
basis for comparison.

Provides qualitative information on
which end use might have been the
fastest growing.
Limitation

Does not measure energy efficiency
developments.

The indicator is influenced by the
penetration rate of different
appliances, the number of inhabitants
per house, the income level of
households, the trends in house size
and dwelling type, the efficiency of
water and space cooling devices, the
type of light bulbs used, the efficiency
of the building envelope, etc.

Provides a general overview of the
trends in aggregate energy intensity.
When energy use by end use is not
known, energy use per occupied
dwelling can be used as an energyintensity indicator.
Some important conclusions can be
drawn if the weather, ownership of
energy-using appliances and
dwelling area are known.

Monitor energy use in the
residential sector.
Combined with energy use per
household, provides useful insights
on what might have been the main
driver of energy consumption.



Residential energy
consumption per
floor area
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

Energy
consumption.
Total floor area.




Does not measure energy efficiency
developments.
Influenced by many factors not related
to energy efficiency such as changes in
income level or energy prices.
Does not measure energy efficiency
developments.
Influenced by many factors not related
to energy efficiency such as changes in
income level or energy prices.
Residential level 1 indicators
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Level 2 indicators: Services Example
Indicator
Space heating
energy
consumption per
value-added
Data required

Energy use for
space heating.

Services valueadded.
Space heating
energy
consumption per
floor area

Energy use for
space heating.

Total floor
area.
Purpose

Provide an indication of the
trends in space heating
energy intensity.
Limitation

This indicator does not take into
account the effect of floor area
and the share of floor area
heated.


Provide an indication of the
trends in space heating
energy intensity.



Space heating
energy
consumption per
floor area heated

Energy use for
space heating.

Total floor area
heated.

Provide a better indicator as it
takes into account the share
of floor area heated.



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Does not provide a distinction
between equipment and
building efficiency.
Does not measure energy
efficiency developments.
Does not take into consideration
the share of floor area heated.
Does not consider the level of
heating required by different
types of buildings.
Does not provide a distinction
between equipment and
building efficiency.
Does not measure energy
efficiency developments.
Does not consider the level of
heating required by different
types of buildings.
Level 3 indicators: Transport Example
Indicator
Data required
Purpose
Limitation
Energy use per
passengerkilometre by
road transport
vehicle

Passenger transport energy
consumption by road transport vehicle.



Passenger-kilometres by road transport
vehicle.
Energy intensity by road
vehicle is a meaningful
summary indicator, if specified
at a detailed enough level.
Intensities can be used to help
develop transportation energy
policies.
Provide insights on the
average fuel economy of the
vehicle stock. As opposed to
energy/pkm, it is not
influenced by vehicle
occupancy.

Energy use by
vehicle
kilometre
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
Stock of vehicles
by type of LDV.

LDV vehiclekilometres.

LDV energy
consumption.



Or fleet
fuel
economy
survey.

The indicator is still affected
by factors that are not
related to energy efficiency
such as the change in vehicle
weight for LDVs within the
fleet and vehicle features.
May mask important
structural changes if the
level of disaggregation is
limited.
May mask embedded
structural changes if the
level of disaggregation is
limited.
Additional indicators
 Indicators that are not necessarily energy
related but which help to explain energy
consumption
 Examples:
 CO2 indicators
 The purpose and limitations identified for
energy efficiency indicators also apply to CO2
indicators
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Aren’t some of the EEIs giving
conflicting results?
 Cannot look at indicators in isolation
 EEIs cannot predict variation in overall energy
consumption or quantify the impact of individual
components or factors on overall energy
consumption.
 Thus, it is often necessary to undertake more
detailed analysis to fully understand the combined
impact of a number of different factors or driving
forces on overall energy consumption.
 Use decomposition or factorization analysis to
explain the interaction between different
elements or factors influencing total energy
consumption
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Decomposition analysis…
… how to get started?
generic
energy efficiency
indicator
energy
consumption
Total
energy
consumption
energy consumption
activity
generic
energy efficiency
indicator
generic
energy
efficiency
indicator
Subsector
or end
use
activity
activity
Sub-sector
or end use
share of
total
activity
What are the impacts of these factors over time?
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Generalised 3-factor energy equation
n
n
Ai Ei
E   A    A   ( Si  I i )
A Ai
i
i
i subsector or end-uses within a given sector
Aggregate activity A
value-added for manufacturing industry and services; population in the
household sector; or as passenger-kilometres and tonne-kilometres,
respectively, for the passenger and freight transport sectors
Sectoral structure S
mix of activities within a sector and further divides activity into industry
sub-sectors, measures of residential end-use activity or transportation
modes
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Energy intensity I
energy use per unit of activity
Impacts on energy consumption over
time…
E  E
YearT
E
Year 0
E  E ACT  ESTR  EINT  ERSD
 Additive or sum form
 Ideally a residual of 0
R  E YearT / E Year0
R  R ACT .RSTR .RINT .RRSD
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 Multiplicative form
 Ideally a residual of 1
Solving the equations…
E   At S i ,t I i ,t
i
d

dt
Si ,t
I i ,t
Et
At


S i ,t I i ,t  
At I i ,t  
At Si ,t
t
t
t
t
i
i
i
t
1
  dt
E0 0
t
t
S i ,t At I i ,t
I i ,t At S i ,t
 Et  t
At S i ,t I i ,t


 ln    
dt   
dt   
dt
t E0
t E0
 E0  0 i t E0
0 i
0 i
Fortunately we do not need to solve this equation
and various methods have been developed…
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Which decomposition methodology?
 Index decomposition analysis is used in energy
decomposition analysis so that indicators with
different units can be combined
 Choice of index decomposition methodology
 Perfect decomposition
 Sub-sectors additive
 Time reversible
 Easy to understand?
 Choice of format
 Additive
 multiplicative
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Overview of different methodologies
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Index
Perfect
decomposition
Subsectors
additive
Time
reversible
Easy to
understand
LMDI I
Yes
Yes
Yes
Moderately
Refined Laspeyres
Yes
Yes
No
Moderately
LMDI II
Yes
No
Yes
Moderately
Fischer Ideal
Yes
No
Yes
Moderately
Simple average/ arithmetic
mean/ divisia (Törnqvist)
No
No
Yes
Moderately
Adjusted PMD I and II
No
Yes
Yes
Difficult
Paasche
No
Yes
No
Very easy
Simple Laspeyres
No
Yes
No
Very easy
Decomposition analysis other choices
 Key issue is the choice of activity variable
 Level of dissaggregation
 Other factors can be added if data is available
 By fuel
 Geographical or regional level
 Fixed base-year vs. rolling base year
 depending on data availability
 Correction for heating degree days, cool degree
days, purchasing power parities and currency
should be incorporated into the calculations
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Annex A in Essentials Manual
 Detailed equations for Laspeyres and Log
Mean Divisia Index (LMDI-1) decomposition
methodologies in both additive and
multiplicative formats
 How to calculate hypothetical energy use
 How to extend energy decomposition analysis
to CO2 decomposition analysis by adding a fuel
mix (including electricity) and a carbon
intensity factor
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Decomposition of residential space
heating
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Aggregate intensity
Structure effect
Efficiency effect
IEA20
United States
UK
Sweden
Spain
Norway
New Zealand
Netherlands
Luxembourg
Korea
Japan
Italy
Hungary
Germany
France
Finland
Denmark
Canada
Belgium
Austria
Australia
Average annual percent change
Decomposition of changes in industry
2.0%
1.0%
0.0%
-1.0%
-2.0%
-3.0%
-4.0%
-5.0%
-6.0%
-7.0%
Decomposition of passenger transport
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The views expressed in this presentation do not necessarily reflect the views or
policy of the International Energy Agency (IEA) Secretariat or of the individual IEA
member countries. The IEA makes no representation or warranty, express or
implied, in respect to the presentation’s content (including its completeness or
accuracy) and shall not be responsible for any use of, or reliance on, the
presentation.
Thank you
[email protected]
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Wrap Up…
How to get started:
 IEA manuals
 Fundamentals on Statistics
 Essentials for Policy Making
 IEA energy efficiency indicators questionnaire
 Collaboration with IEA energy efficiency
indicator teams
© OECD/IEA 2014
Take away messages
 Decomposition analysis is essential to analyze
energy end-use
 Energy consumption can be decomposed in
Activity (A), Structure (S) and Intensity (I)
 LMDI I preferred method
 Fixed base-year vs. rolling base year
(depending on available data)
 Data corrections should be applied where
possible (HDDs, CDDs, PPPs, etc.)
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IEA Energy Efficiency Indicators
Energy
Efficiency
Indicators
Policy
Data
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Calculations
& Analysis