Guidance on Calculating GHG Emission Reduction
Contributions of Electronic Components
Ver.2

July 2022
Japan Electronics and Information Technology Industries Association
Electronic Components Board,
ESG Committee,
Subcommittee on Electronic Components Technology Environment,
Electronic Components LCA-WG＜Note＞
This guidance was voluntarily prepared by Electronic Components Board, ESG
Committee, Subcommittee on Electronic Components Technology Environment ofJapan Electronics and Information Technology Industries Association for the purpose ofbeing used by each company in the case of calculation of GHG reduction contributions ofelectronic components. Consequently, users are kindly reminded that any decisions
concerning the use of this guidance should be taken under their own responsibility.
It should also be noted that this guidance can be revised without previous notice incase of amendment of legislation herein referenced, or when important relevant items
having a different context of what is stated here are announced.
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Table of contents
PartⅠ Guidance for calculation of contribution
1. Introduction (Background and purpose) ........................................................................ 3
2. Terms and definitions...................................................................................................... 3
3. GHG reduction contributions by products or services ................................................... 5
4. GHG reduction contributions by electronic components ............................................... 6
5. Contribution in the use stage ......................................................................................... 7
5.1 Difficulties in calculating contribution of electronic components............................ 7
5.2 Basic idea of calculation of contribution ................................................................... 8
5.3 Calculation of the direct contribution ....................................................................... 95.3.1 Procedures to calculate direct contributions ...................................................... 9
5.3.2 Accumulation method ....................................................................................... 125.3.3 Product grouping ............................................................................................... 13
5.4 Calculation of the indirect contribution.................................................................. 13
5.4.1 Estimation methods for indirect contribution ................................................. 13
5.4.2 Existing guideline/guidance.............................................................................. 14
6. Contribution other than the use stage ......................................................................... 14
7. Key points to keep in mind in communications ........................................................... 15
7.1 Subtraction from GHG emissions ........................................................................... 15
7.2 Positioning of indirect contribution ........................................................................ 15
7.3 Avoidance of double counting .................................................................................. 15
8. References ...................................................................................................................... 16
PartⅡ Calculation formula
1. Basic formula ................................................................................................................. 17
2. Necessary information .................................................................................................. 17
3. List of operating hour.................................................................................................... 18
4. Detailed calculation formula......................................................................................... 20
5. Examples of calculation ................................................................................................ 21

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1. Introduction (Background and purpose)
It is concerned that climate change due to global warming may have serious impacts inthe near future. Under such conditions, each developed country has started addressing
realization of the low carbon society.
Industries in Japan so far have contributed to prevention of global warming byimproving energy-use efficiency in production activities. Lately, however, in addition toconventional activities, they are addressing GHG emission reductions by means of thedevelopment and provision of products and services based on new technologies.
There are two reasons, can be pointed out as the background, why industries in Japan
have started addressing such activities.
First, because of heightening of environmental awareness, general consumers havebecome sensitive to energy consuming products and negative environmental impacts offactories. In reality, although consumers are enjoying benefits of using products andtake such for granted, the negative side alone gains prominent attentions. Therefore, itis necessary to show positive impacts on the environment. Second, it is important toallege the superiority by quantifying and showing the advantages of products andenergy efficiency of the production line in Japanese companies.
As a result of such activities, GHG emission reductions by products and services in theuse stage have become recognized widely as contribution to society due to businessefforts of the companies. Furthermore, standardization is going on throughpreparations and publications of guidelines, etc., by International ElectrotechnicalCommission (IEC), the Institute of Life Cycle Assessment, Japan and some industry
associations.
Although many companies and organizations in electrical and electronics industries inJapan have already published actual or prospective numerical value of GHG reduction
contributions, companies and organizations committing such activities will increase by
the improvement of social recognition and the progress of foundation development
described above.
Purposes of this guidance are to show the basic idea and methods to calculate GHG
reduction contributions of electronic components and to avoid confusions due to massive
reductions figures calculated by various methods and decreases in credibility ofnumerical value.

2. Terms and definitions
・Amount of activity
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The degree of company’s activities expressed by indicator.
(Ex: number of units sold, amount of sales, amount of energy used, etc.)
・Baseline
Reference product or value in the comparison to calculate the amount of GHG
emission reduction contributions
・Contribution ratio
The ratio for calculating the amount of GHG reduction contributions attributable tothe target product depending on the degree of its contribution.
・CO2 emission coefficient
Numerical data to indicate how much CO2 is emitted to supply 1kWh. They are
expressed by units such as kg-CO2/kWh, t-CO2/MWh, etc.
・Double countIt means counting some overlapped values in aggregate calculation.
・GHG : Greenhouse gas
Seven greenhouse gases are subject to the United Nations Framework Convention on
Climate Change (UNFCCC) and the Kyoto Protocol: Carbon dioxide (CO2), Methane(CH4), Dinitrogen monoxide (N2O), Hydrofluorocarbon (HFCs), Perfluorocarbon(PFCs), Sulfur hexafluoride (SF6), Nitrogen trifluoride (NF3).
This Guidance particularly targets at energetic origin CO2.
・GHG emission intensity
The amount of GHG emitted in the production processes per unit. It is expressed byunits such as t-CO2/million yen, t-CO2/t, etc.
・IEC TR62726
The guidance for calculation of GHG reduction contributions of electrical andelectronic products issued by International Electrotechnical Commission (IEC).
“Guidance on quantifying greenhouse gas emission reductions from the baselineforelectrical and electronic products and systems”
・Lifecycle
Processes from the birth to the death of products and services from raw material
acquisition or generation of natural resources to the final disposal.
・Lifecycle stage
Each stage of raw material production, assembly of end products, disposal, etc., in
the lifecycle.
・Lifetime
Period from the start of use to the end of use for the products. Product lifetime.
Service life.
4・Load factor
Load ratio of practical usage to maximum design capacity.
・Primary data
The newly collected data for specific purposes.
・Secondary data
The data already collected for other purposes.
・Target product
The product(s) that is/are subject to calculation of GHG emission reduction
contributions.
・Target year
The year subject to the accumulation of emission reduction contributions. In theaccumulation of the lifetime, the number of products sold in the target year, and in
the annual accumulation, the number of products in the market in the target year
including the products sold in the past is to be figured out.
・Value chain
A chain consisting of a sequence of values related to products and organizations fromthe stage of raw material procurement through the use of the product(s) to thedisposal. Consumers using the product(s) are included in the value chain.

3. GHG reduction contributions by products or services
As mentioned in the introduction, as to calculating GHG reduction contributions,policies have been expressed by several standards, industry guidelines, etc. The
common concept of these standards is that the GHG emission reductions are derived
from the comparison between target product and the baseline. Therefore, in calculationof emission reduction contributions, it is important to see the technical superiority ofthe target product in connection with environment load reductions.
The image of GHG reduction contributions quoted from IEC TR627261) is shown in
FigureⅠ—1.

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GHG emission

GHG reductions in comparison to the baseline

Reference

Target Product(Baseline)
FigureⅠ—1

Image of GHG emission reduction contributions

4. GHG reduction contributions by electronic components
Technological efforts in developments and productions for electronic components leadto environmental load reductions. Impacts of these efforts to the environment throughthe lifecycle of electronic components are shown in TableⅠ—1.
From TableⅠ—1, we can see technological efforts in development and production ofelectronic components contribute to environmental load reductions at various stages ofthe lifecycle.
As a specific example, downsizing of electronic components contributes to resource andenergy savings at the production stage and contributes to energy savings at upperstream of the value chain as well. Accordingly, it contributes to GHG emission
reductions.
In this guidance, the GHG reduction contributions through electronic components isdefined as “GHG emission reduction realized at the stages other than its own businessareas in lifecycle through technological efforts in development and production ofelectronic components.”

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TableⅠ—1 Impacts and range given by technological efforts concerning development andproduction of electronic components
Lifecycle stage
Raw material
Technical

production

approachDownsizing＊1

Function
improvement＊2Electronic

Electronic

Finalcomponent

component

product

production

transportationassembly

EnergyEnergy/Resource/ResourcesavingsavingEnergyEnergy/Resource/ResourcesavingsavingEnergysavingEnergysavingEnergy/ResourcesavingFinal product

Final productuse

disposal

EnergyEnergysaving＊5

savingEnergyEnergy/ResourcesavingsavingEfficiency

Energyimprovement＊3

savingExtendinglifetime＊4

EnergyEnergyEnergy/Resource/Resourcesavingsavingsaving＊1

Downsizing： to make external dimensions smaller with functions as it stands＊2

Function improvement： to improve functions with external dimensions as it stands.

＊3

Efficiency improvement： to make the necessary power to execute functions smaller.

＊4

Extending lifetime： to extend the product life with functions as it stands.

＊5

In the case where the end product is transport equipment alone.

5. Contribution in the use stage
5.1 Difficulties in calculating contribution of electronic components
Electronic components behave as key parts for varieties of equipment such as homeelectric appliances, IT equipments, vehicles, industrial machinery, etc. and thereby they
contribute to energy saving through such equipment.
In IEC TR627261), it is recommended to assess final products in order to calculate
GHG reduction contributions by electronic components. However, in the case ofdevelopment and supply of intermediate products such as an electronic component, atthe same time of improvement of the target product, design of the final product is to bechanged as well, and furthermore, improvements of other intermediate products often
go together. Accordingly, it is difficult to calculate GHG emission reductions byelectronic components alone.
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In the consideration of possibility to calculate GHG reduction contributions, as fordevices used at electric power transmission route such as the power supply unit,transformer, and DC/DC converter, it is possible to directly calculate contributions.
Because it is possible to directly calculate them from the power consumption reduction
effects of the electronic component itself. On the other hand, as for the components
contribute to the operation control for energy saving for equipment, or passive
components such as chip ceramic capacitor which do not directly contribute to energy
saving of the equipment and yet indispensable for forming the electronic circuit, it isdifficult to directly quantify its contribution.
5.2 Basic idea of calculation of contribution
The calculation method of energy-derived CO2 emission reduction contribution amountof electronic components can be organized into the following three according to thecharacteristics of electronic parts and how they are involved in the reduction
contributions of final products. 2)(a) Calculation based on the reduction of power consumption of electronic
components(b) Calculation based on the energy consumption reduction of the final product due
to the effect of electronic components(c) Calculation based on the contribution ratio of electronic components to thecontribution of the final product(a) is mainly applied to electronic components that convert electric power or voltage,
and the performance of these electronic components affects the power utilization
efficiency of the final product. (b) is mainly applied to cases of improvement in fuel orelectricity efficiency of transportation equipment by reducing the weight of electronic
components, but other cases are expected to increase. (C) is applied when the amount of
CO2 emission reduction contributions of the target electronic component cannot becalculated by either method (a) or (b).
The basic formula for calculating the contribution amounts directly from the energy
consumption of electronic components or final products by the methods (a) or (b) is asfollows (1).

8𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑜𝑜𝑜𝑜 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐= 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴 𝑜𝑜𝑜𝑜 𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑜𝑜𝑜𝑜 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 × 𝐶𝐶𝐶𝐶2 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓

× 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣(1)

The basic formula for indirectly calculating the contribution amount by the method (c)is as shown in formula (2).
𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑜𝑜𝑜𝑜 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐= 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑜𝑜𝑜𝑜 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝

× 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟 𝑜𝑜𝑜𝑜 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 × 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣(2)

Hereafter, contribution derived from (1) is called as the “Direct contribution” andcontribution derived from (2) is called as the “Indirect contribution”
5.3 Calculation of the direct contribution
The formula (1) shown in 5.2 is rewritten into formula (3), which is more practicalwhen calculating the contribution amount directly from the power consumption ofelectronic components.
𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 = (𝑊𝑊𝑊𝑊𝑊𝑊𝑟𝑟 − 𝑊𝑊𝑊𝑊𝑟𝑟 ) × 𝐿𝐿 × 𝐻𝐻𝑜𝑜𝑜𝑜 × 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 × 𝑆𝑆

Wblr : Electric power consumption of baseline at rated condition(3)

Wtr :Electric power consumption of target product at rated condition
L : Load factor

Hop : Hours of operation
Coef : CO2 coefficient
S : Sales volume

In the next clause, based on formula (3), the procedures to calculate annual
contribution of a product will be explained.
5.3.1 Procedures to calculate direct contributions
Step1 Defining the target productDefine the product subject to the calculation of contribution. In what follows, thisproduct is called the target product.
Step2 Setting of functional units
Set the functional units of the target product. The functional units are the values9to express basic functions of electronic components. As examples, as for the power
supply unit, it is rated output ○○W, as for the inductor, it is inductance △△μH.
The functional unit can also be set to a numerical value in consideration of theusage state in the final product.
Step3 Defining the baseline
Set the baseline, as the benchmark for comparison in the calculation ofcontributions. In the case where the baseline is a product, the item having
functional units as with the product set in step 2 to be assessed is to be chosen. In
the case where the baseline is the values set by laws and systems such as power
consumptions, etc., the values set for the product having the same functional units
is to be chosen as well. Examples of the baseline are shown below.
《Examples of the baseline》
・In-house old products
・Other products having equivalent functions
・The product of the highest market share
・Average value of the industry
・Standard values set by laws or systems
The baseline may vary depending on the country / region where the target
products are populated. According to “Guidelines for Assessing the Contribution of

Products to Avoided Greenhouse Gas Emissions Ver.2”3), if a product that provides
the same function is not distributed in the region / country, the baseline should be
defined with the consideration that other product which is popular in other country/ region and provide the same function might be procured.
In addition, when target products are sold to multiple regions / countries, thepopular products may differ in each region / country. In such cases, it is desirable todefine a baseline for each region / country where sales are made and calculate theamount of reduction contribution for each. However, if it is difficult to grasp
information related to the defining of baselines in some regions / countries, thebaseline with the least reduction contribution amount could be defined as thebaseline for those regions / countries.
Step4 Identifying improvement effects
Identify improvement effects lead to reductions of power consumption in use ofelectronic components. As typical examples of improvement effects are theimprovement of the conversion efficiency of the power supply unit and thetransformer, and lowering-resistance values of passive components such as
inductors.
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Step5 Calculation of difference in rated power consumption
Setting detailed calculation formula based on improvement effects identified instep 4, then calculate the differences of rated power consumption between thetarget product and baseline. (Examples will be shown in Part II.)
Step6 Setting of load factor
In order to reflect actual operation status to contribution, setting the load factor
and multiply difference in power consumption under the rated conditions derived
from step 5. Taking the load factor in calculation, over-counting of contribution can
be avoided.
Load factors are set based on information obtained through hearing fromengineers and publicly known literatures and data, etc.
Step7 Identifying the final products and setting operating time
Identify the final product in which target product is built-in. By identifying thefinal products, the annual operating time can be set. The value derived in step 6(Differences in power consumption) multiply by operating time. The value derived
here is electrical energy of unit Wh. (The operating time of major final products will
be shown in Part II.)In the case where there are plural final products having the built-in target product,
contribution is to be calculated for each of them. In the case where it is difficult to
calculate all the final products, calculation can be carried out by selecting
representatives. However, in this case, it is necessary to clarify specific reason forsuch selection.
In identifying the final product for electronic components, there is a possibility
that the incorporated product will be incorporated into a larger system. In suchcases, the product whose CO2 emission reduction amount can be calculated
independently is regarded as the final product.
Step8 Setting of CO2 emission factor: Calculation of contribution per productContribution per product is calculated multiply the annual electric energy
reduction derived in Step 7 by CO2 emission factor of electricity. Contribution isexpressed as CO2 reduced quantity (g-CO2, kg-CO2, t-CO2, …).
It is recommended to use the CO2 factor of the year to be accessed in the area
where the final products are used. However, in the case where it is difficult to
identify the area where the final products are used, or in the case where the CO2
factor in identified area is unclear, the values published by Intergovernmental
Panel on Climate Change (IPCC), International Energy Agency (IEA), etc., are uses
as representative values. In the case external communications or internal
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communications, sources of CO2 emission factors need to be specified.
Step9 Identifying the sales volume: Calculation of contribution to society
Identify the volume of sales of the target product in the target year. Contribution
to society is calculated by multiplying contribution per product by the volume ofsales.
In evaluating the contribution of parts and materials, it may be difficult to grasp
the sales volume for each application or for each country / region. Regarding thispoint, “Guidelines for Assessing the Contribution of Products to Avoided

Greenhouse Gas Emissions Ver.2”3) allow the calculation, after showing therationale, based on assumptions of grouping similar regions / countries together orsetting representative regions / countries.
5.3.2 Accumulation method
Procedures to calculate annual contribution are shown in 5.3.1, however, electrical andelectronics products are durable goods, so they contribute for several years after beingbought by consumers. Because of these characteristics of the electrical and electronics
products, the following two aggregate calculation methods are shown in IEC TR627261).
①

Accumulation based on lifetime GHG reductions
The method to sum up contributions through lifetime.
Multiply the annual contribution calculated in 5.3.1 by the lifetime of the target
product.
The lifetime of the product is set based on legal durable years, average repurchaseperiod in market, physical life, etc.

②

Accumulation based on annual GHG reductions
The method to sum up the annual contribution in the target year. Multiply annual
contribution calculated in 5.3.1 by the amount of target product in the market. This
amount includes the target product sold in the target year and sold in past but yet
stay in the market because they are still within product lifetime.
The image quoted from IEC TR627261) is shown in FigureⅠ—2.

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①Lifetime accumulation

Products sold in thetarget year

Products sold in
the past②Annual accumulation

Target year

FigureⅠ—2

Year

Image of accumulation of contribution

5.3.3 Product grouping
Even within the same product group, the product names of electronic components are
subdivided according to size and characteristics, and it is difficult to individuallycalculate the amount of contribution for all product names. In such cases, as proposedby The Institute of Life Cycle Assessment, Japan4), a method of grouping products andcalculating the contribution amount is effective. The procedure for calculating theamount of contribution by grouping is as shown below. At this time, it is necessary to
clarify the criteria for grouping and the basis for selecting representative products.
①

Group products from the perspective of function, final product, etc.

②

Determine the representative product for each group and calculate the emission
reduction contributions amount of the representative product.

③

Estimate the reduction contributions amount of the entire product group from thesales volume or sales amount of the group.

5.4 Calculation of the indirect contribution
5.4.1 Estimation methods for indirect contribution
As mentioned in 5.1, in calculation of contribution of electronic components, in somecases, it is impossible to calculate because of technical or theoretical reasons. In thiscase, GHG reduction contributions of the target product are to be estimated in indirect
method. As for the estimation methods, information from the final product13

manufacturers, estimation of effects of target product alone by means of simulations
and calculation based on the contribution ratio are available.
5.4.2 Existing guideline/guidance“The guidelines for Assessing the Contribution of Products to Avoided Greenhouse Gas

Emissions Ver.2”3) shows the method of allocating the GHG emission reduction
contribution amount of final products to stakeholders on the value chain according to
the contribution ratio.
Electrical and electronics industries in Japan published case studies of “Green IT

Promotion Council Survey Analysis Committee Comprehensive report (2008 - 2012) ～Contribution of green IT toward the low-carbon society～”5) and “A calculating method
to estimate semiconductors and electronic components contribution to other industries’
CO2 reduction”6). In these precedent cases, as examples of indicators for determining thecontribution ratio, the amount of money (cost / value), the environmental load at thestage of use (CO2 emissions, etc.), the amount of resources / energy input in the supply
chain, etc. are shown as examples.
The image of allocation by contribution ratio is shown below.
Contribution by the final products or services

Setting of contribution ratio

Materials

FigureⅠ—3

Electronic components

Semiconductors

OthersImage of quantification of indirect contribution by contribution ratio

6. Contribution other than the use stage
In lifecycles of the final products, energy consumptions at the use-stage are largest.
Accordingly, calculation of contribution is carried out with a focus on the use-stage.
However, in the case of intermediate products such as electronic components usedbuilt-in final products, GHG emission reduction effects due to technological efforts may
appear at the upper stream of the value chain.
Effects of downsizing and extending lifetime mainly come from the GHG emission
reductions due to reductions of production energy and resources consumptions at the14

lifecycle stages upper than the electronic components production stage.
Calculation of contribution, preferably, is to be carried out getting and using all
primary data. However, data collection through the value chain, in some cases, may beformidable work. In such cases, contribution can be estimated by using materials
purchase data (primary data) and the secondary data showing GHG emission originalunits.

7. Key points to keep in mind in communications
7.1 Subtraction from GHG emissions
When communicating using contributions, you must be careful not to mislead
stakeholders. In particular, there is a concern that the method of subtracting theamount of emission reduction contributions from the amount of GHG emissions oforganization may be regarded as greenwash. Under these circumstances, many
companies use a method of expressing the amounts of emissions and contributions side
by side.
7.2 Positioning of indirect contribution
As introduced in 5.4, the purpose of calculation of indirect contribution is to calculate
contribution of each constituent within the contribution of the final products, and it is
not to separate contribution of the final products.
Therefore, in the case where contribution of electronic components, constituent of the
final products, is claimed, the fact that the resultant values are partial values ofcontribution of the final product has to be kept in mind.
Furthermore, in communications using indirect contribution based on contribution
ratio, method to identify contribution ratio and its basic idea shall be shown.
7.3 Avoidance of double counting
Cautions in calculation of contribution are double counting.
As a result of calculation of amounts of CO2 emission reduction contributions, if thecontribution of the electronic components exceeds contribution amount of final products
in which the target product is built-in, it is theoretically contradictory. Furthermore, if
the values of reduction contribution calculated by each company and industry
associations are exorbitant ratio compare to those of whole world, credibility of values
goes down and eventually meaning of the reduction contribution itself would break
down. Therefore, the double count of contribution is to be eliminated as far as possible.
15

Double counting may take place in communications in various scenes such as
inter-industry, inter-company (in-industry), inter-divisions (in-house), etc.

8. References
1) International Electrotechnical Commission (IEC) (2014) : TR62726 Guidance onquantifying greenhouse gas emission reductions from the baseline for electrical andelectronic products and systems
2) TDK Corporation（2021）：A Case Study on Quantifying the Amount of CO2 Emission
Reduction of Electronic Components（Journal of Life Cycle Assessment, Japan.
Vol.17 No.2 April 2021, 95-102）*3) The Institute of Life Cycle Assessment, Japan (2015): Guidelines for Assessing theContribution of Products to Avoided Greenhouse Gas Emissions Ver. 2*4) Mizuho Research & Technologies, Ltd.（2021）：Introduction to Guidelines on theAssessment and Disclosure of Organizational Contribution to the Avoided Emissions（Journal of Life Cycle Assessment, Japan. Vol.17 No.2 April 2021, 68-73）*
5) JEITA Green IT Promotion Council Survey Analysis Committee（2013）: Green IT
Promotion Council Survey Analysis Committee Comprehensive report (2008 - 2012)～Contribution of green IT toward the low-carbon society～*6) Japan Electronics and Information Technology Industries Association (JEITA),Electronic Components Board, Subcommittee on Electronic Components Technology
Environment, and Semi-Conductor Board (JSIA), Semiconductor Environment
Committee (2012): Concept of calculating the contribution ratio of semiconductors
and electronic components to the amount of CO2 emission reduction contributions of
products** written in Japanese

16PartⅡ Calculation formulaThis part shows, necessary information and calculation formula. As mentioned in PartⅠ, the amount of GHG emission reduction contribution is calculated in the comparison
between target product and baseline.

1. Basic formula
The formula (1) for calculating the amount of direct contribution shown in Part I isexpressed as the following formulas (4) and (5) for electrical and electronic products andfor transportation equipment, respectively. The content of equation (4) is basically thesame as that of equation (3) shown in 5.3.
【Electrical and electronic products】

𝐶𝐶𝑑𝑑 = ∆𝑊𝑊𝑟𝑟 × 𝐿𝐿 × 𝐻𝐻𝑜𝑜𝑜𝑜 × 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒 × 𝑆𝑆

(4)

Cd : Amount of direct contribution (kg-CO2)
ΔWr : Power consumption reduction under rated conditions (kW)
L : Load factor
Hop : Hours of operation (h)Coefe : CO2 emission factor of electricity (kg-CO2/kWh)S : Sales volume【Transportation equipment】

𝐶𝐶𝑑𝑑 = ∆𝐸𝐸 × 𝐷𝐷𝑜𝑜𝑜𝑜 × 𝐸𝐸𝐸𝐸 × 𝑆𝑆

(5)

ΔE : Reduction of fuel / power consumption per mileage（ℓ/km, kWh/ km）
Dop : Mileage（km）

EF : CO2 emission factor of fuel or electricity（kg-CO2/ℓ, kg-CO2/kWh）S : Sales volume

2. Necessary information
Table below shows necessary information to calculate direct contribution.
TableⅡ-1
Item

Description

Target productProduct to be assessed to calculate GHG reduction
contributions
17

Item

Description

Functional unit

Function of product which is quantified by specific unit.

Baseline

The base of comparison in the calculation of contributions.
Baseline is a product which might be used if target producthas not been exists, or is a value set by law or initiative.
Functional unit of baseline shall be equal to target product.

Improvement

Effect of improvement leads to GHG emission reductions.

effectLoad factor

Ratio of actual load to rated condition in the use phase.

Operating hour

Hours of operation in the specific term (e.g. 1 year).
Operating hour of electronic components is determined by
final product in which electronic components built-in.

Sales volume

Volume of target product sold in specific term.

CO2 emission

Coefficient to convert the amount of energy into CO2-e.

coefficient
Contribution

Raito of contribution by electronic components to theratio

contribution of final product.

3. List of operating hour
Table below shows operating hour of electrical appliances.
TableⅡ—2
CategoryHome

Appliance

TV setDuration(y)10AnnualLifetime

operatingoperatinghour (h)hour(h)1,643

16,425

Quotation source
Japan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon

appliance

Society, implementation guide “TV set”

Refrigerator

10.4

8,760

91,104

Japan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon
Society, implementation guide “Refrigerator”

Air conditioner

6

3,276

19,656

Japan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon
Society, implementation guide“Air conditioner”

18Category

Appliance

Lighting

Duration(y)10AnnualLifetime

operatingoperatinghour (h)hour(h)2,000

20,000equipment

Quotation source
Japan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon
Society, implementation guide“Light equipment”

PC/IT

Microwave oven

10

91

913

Top Runner Program (Japan)

Washing machine

9.1

164

1,495

JIS C 9921-4：2009

DVD player

8

821

6,570

Top Runner Program (Japan)

PC

5

712

3,560

Japan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon
Society, implementation guide“Client PC”

HDD

5

8,322

41,610Japan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon
Society, implementation guide“Magnetic disk drive”

IT equipment

5

8,322

41,610Japan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon
Society, implementation guide“Server PC”

Routing equipment

5

8,760

43,800

Action Plan for Commitment to a Low-Carbon
Society, implementation guide“Routing equipment”

Printer, PPC,

5

2,080

10,400

ScannerJapan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon
Society, implementation guide“Printer”

Industry/
Infrastructure
Automobile

Industrial and

11

8760

96,360Infrastructural

Official durable years table in Japanese tax
law

machinery
Automobile

10

433

4,334

Report of Ministry of Land, Infrastructure,
Transport and Tourism, Japan

Audio and Visual

10

433

4,334

10

433

4,334

set for automobile
EV,HEV

Report of Ministry of Land, Infrastructure,
Transport and Tourism, Japan
Report of Ministry of Land, Infrastructure,
Transport and Tourism, Japan

RenewableenergySolar power

20

8,760

system

175,200

Japan Electrical & Electronics industries’
Action Plan for Commitment to a Low-Carbon
Society, implementation guide”Solar power system”

19

4. Detailed calculation formulaThis part shows examples of improvement points which lead to GHG emission
reduction contributions and detailed calculation formulas.
Ex.1: Internal power supply unit
Functional unit: Rated power (out-put)
Improvement point: Improving efficiency of conversion
Calculation formula

𝐶𝐶𝑑𝑑 = �

1

𝐸𝐸𝐸𝐸𝐸𝐸𝑏𝑏𝑏𝑏−

1

𝐸𝐸𝐸𝐸𝐸𝐸𝑡𝑡� × 𝑃𝑃𝑟𝑟 × 𝐿𝐿 × 𝐻𝐻𝑜𝑜𝑜𝑜 × 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒 × 𝑆𝑆

Cd : Amount of direct contribution（kg-CO2）
Effbl : Conversion efficiency of baseline

Efft : Conversion efficiency of target productPr : Rated power (out-put)（kW）
L : Load factor

Hop : Operating hours（h）

Coefe : CO2 emission coefficient of electricity（kg-CO2/kWh）S : Sales volume

Ex 2：DC-DC converter for EV/ PHEV/HEVFunctional unit: Rated power (out-put)
Improvement points : ①Improving conversion efficiency②Weight saving
Calculation formula ① : Improving conversion efficiency

𝐶𝐶𝑑𝑑 = �

1

𝐸𝐸𝐸𝐸𝐸𝐸𝑏𝑏𝑏𝑏−

1

𝐸𝐸𝐸𝐸𝐸𝐸𝑡𝑡� × 𝑃𝑃𝑟𝑟 × 𝐿𝐿 × 𝐻𝐻𝑜𝑜𝑜𝑜 × 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒 × 𝑆𝑆

Cd : Amount of direct contribution（kg-CO2）
Effbl : Conversion efficiency of baseline

Efft : Conversion efficiency of target productPr : Rated power (out-put)（kW）
L : Load factor

Hop : Operating hour（h）

Coefe : CO2 emission coefficient of electricity（kg-CO2/kWh）20

S : Sales volume

Calculation formula ② : Weight saving

𝐶𝐶𝑑𝑑 = (𝑤𝑤𝑏𝑏𝑏𝑏 − 𝑤𝑤𝑡𝑡 ) × 𝐸𝐸𝑒𝑒 × 𝐷𝐷𝑜𝑜𝑜𝑜 × 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒 × 𝑆𝑆

Cd : Amount of direct contribution（kg-CO2）
Wbl : Weight of baseline（kg）

Wt : Weight of target product（kg）

Ee : Electricity consumption coefficient of EV/PHEV（kWh/km/kg）（Notice 1）
Dop : Mileage（km）

Coefe : CO2 emission coefficient of electricity（kg-CO2/kWh）（Notice 2）
S : Sales volume

Notice1: Fuel consumption coefficient shall be used for HEV, because energy
source of HEV is fuel like a gasoline, light oil or etc.

Notice2: CO2 emission coefficient of fuel shall be used for HEV, because
energy source of HEV is fuel like a gasoline, light oil or etc.
Ex.3 Inductor for power circuit
Functional unit: Inductance
Improvement point: Reducing direct current (DC) resistanceCalculation formula

𝐶𝐶𝑑𝑑 = {(𝑅𝑅𝑏𝑏𝑏𝑏 − 𝑅𝑅𝑡𝑡 ) × (𝐼𝐼 × 𝐿𝐿)2 } × 𝐻𝐻𝑜𝑜𝑜𝑜 × 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒 × 𝑆𝑆
Cd : Amount of direct contribution（kg-CO2）
Rbl : DC resistance of baseline（Ω）

Rt : DC resistance of target product（Ω）
I : Rated amperage value（A）
L : Load factor

Hop : Operating hour（h）

Coefe : CO2 emission coefficient of electricity（kg-CO2/kWh）S : Sales volume

5. Examples of calculation

This part shows case studies of Internal power supply unit with one final product andwith multiple final products.
Notice: All numerical value in this part is the one of supposition and is different fromthe actual numerical value.
21

Case1: Final product is single
Target product: Internal power supply unit
Functional unit: Rated power (out-put) 150W
Final product: Industrial machinery《Calculation condition》
Improvement point: Improving conversion efficiency
Before improvement: 80%
After improvement: 85%
Load factor: 70%
Annual operation hour: 8760 hours
Lifetime: 11 years
CO2 emission coefficient: 0.475 kg-CO2/kWh(Source: IEA CO2 emissions from fuel combustion 2021)
Sales volume: 10,000 unit
Calculation condition is applied to next formula for a case of improving conversion
efficiency of internal power supply unit

𝐶𝐶𝑑𝑑 = �1
1−
� × 𝑃𝑃𝑟𝑟 × 𝐿𝐿 × 𝐻𝐻𝑜𝑜𝑜𝑜 × 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒 × 𝑆𝑆
𝐸𝐸𝐸𝐸𝐸𝐸𝑏𝑏𝑏𝑏 𝐸𝐸𝐸𝐸𝐸𝐸𝑡𝑡

Cd : Amount of direct contribution（kg-CO2）
Effbl : Conversion efficiency of baseline

Efft : Conversion efficiency of target productPr : Rated power (out-put)（kW）
L : Load factor

Hop : Operating hour（h）

Coefe : CO2 emission coefficient of electricity（kg-CO2/kWh）S : Sales volume

Calculation under a supposition (Lifetime accumulation) is11
� × (150 × 10−3 ) × 0.70 × (8760 × 11) × 0.475 × 10000
𝐶𝐶𝑑𝑑 = �−0.80 0.85＝ 3.5×106 kg-CO2

22

Case2: Final products are plural
Target product: Internal power supply unit
Functional unit: Rated power (out-put) 150W
Final products: TV set, PC, PrinterIn this case, firstly calculating the amounts of contributions for each final products,
then accumulate all contributions.
《Calculation condition : TV set》
Point of improvement: Improving conversion coefficient
Before improvement: 80%
After improvement: 85%
Load factor: 70%
Annual operating hour: 1643 hours
Lifetime: 10 years
CO2 emission coefficient: 0.475 kg-CO2/kWh(Source: IEA CO2 emissions from fuel combustion 2021)
Sales volume: 50,000 units
Calculation formula for TV set (Lifetime accumulation) is

C𝑑𝑑 = �11
� × (150 × 10−3 ) × 0.70 × (1643 × 10) × 0.475 × 50000−
0.80 0.85= 3.0×106 kg-CO2《Calculation condition: PC》
Point of improvement: Improving conversion efficiency
Before improvement: 80%
After improvement: 85%
Load factor: 70%
Annual operating hour: 712 hours
Lifetime: 5 years
CO2 emission coefficient: 0.475 kg-CO2/kWh（Default value set by Japanese law）
Sales volume：10,000 units
Calculation formula for PC (Lifetime accumulation) is
23

C𝑑𝑑 = �11
� × (150 × 10−3 ) × 0.70 × (712 × 5) × 0.475 × 100000−
0.80 0.85= 1.3×106 kg-CO2《Calculation condition: Printer》
Point of improvement: Improving conversion efficiency
Before improvement: 80%
After improvement: 85%
Load factor: 70%
Annual operating hour: 2080 hours
Lifetime: 5 years
CO2 emission coefficient: 0.475 kg-CO2/kWh(Source: IEA CO2 emissions from fuel combustion 2021)
Sales volume: 30,000 units
Calculation formula for Printer（Lifetime accumulation）isC𝑑𝑑 = �11
� × (150 × 10−3 ) × 0.70 × (2080 × 5) × 0.475 × 30000−
0.80 0.85= 1.1×106 kg-CO2

Therefore, total contribution amount of power supply unit isC𝑑𝑑 : total = (3.0 + 1.3 + 1.1) × 106= 5.4×106 kg-CO2

24

《Issuance / revision history》

January 2016, First edition issued
July 2022, Revised 2nd edition25