JCM_ID_AM024_ver01.0
Sectoral scope: 03
Joint Crediting Mechanism Approved Methodology ID_AM024“Replacement of diffuser with aerator in aeration pond”
A. Title of the methodology
Replacement of diffuser with aerator in aeration pond, Version 01.0

B. Terms and definitions
Terms

Definitions

Diffuser

Aeration device in the shape of a disc, tube or plate, which isused to supply air from blowers into wastewater for aerobic
wastewater treatment by producing fine bubbles in aeration
ponds for wastewater treatment.

Aerator

Aeration device without power unit, which is used to supplyair from blowers into wastewater for aerobic wastewater
treatment by mixing air and wastewater in itself andproducing water circulation in the entire aeration ponds.

C. Summary of the methodology
Items
GHG

emissionmeasures

Summary
reduction For aerobic wastewater treatment, aeration device(s) is(are)used for supplying air into wastewater. Replacement of thediffuser with the aerator enables to reduce air discharge pressure
atblower(s),torunblower(s)notcontinuously

butintermittently and to reduce discharge amounts of air fromblower(s). By these effects, electricity consumption at blower(s)can be reduced.
Calculation
emissions

ofreference Reference emissions are calculated with electricity consumptionof blower(s) connected with project aeration devices of aerator(hereinafter referred to as “project blower(s)”), ratio of
operating time of blower(s) connected with reference aeration
devices of diffuser (hereinafter referred to as “reference1

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blower(s)”) and project blower(s), ratio of shaft power ofreference/project blower(s), and CO2 emission factor for
consumed electricity.
Calculationofproject Project emissions are calculated with electricity consumption ofemissions

project blower(s) and CO2 emission factor for consumed
electricity.

Monitoring parameters

× Electricity consumption at project blower(s)× Operating time of project blower(s)× Stop time of project blower(s) during intermittent operation
× Discharge pressure of project blower(s)× Rotations per minute of project blower(s)D. Eligibility criteria
This methodology is applicable to projects that satisfy all of the following criteria.
Criterion 1

Aerator(s) is(are) installed to replace existing diffuser(s) in existing aeration
pond(s) for wastewater treatment.

Criterion 2

Effluent wastewater quality meets the wastewater quality standards on items
such as biochemical oxygen demand (BOD), chemical oxygen demand (COD)
and total suspended solids (TSS)

which are applicable to the project site.

E. Emission Sources and GHG types
Reference emissions
Emission sources

GHG types

Electricity consumption by blower(s) which supply air to diffuser(s)CO2Project emissions
Emission sources

GHG types

Electricity consumption by blower(s) which supply air to aerator(s)CO2

F. Establishment and calculation of reference emissions
F.1. Establishment of reference emissions
The shaft power of reference blower(s) and project blower(s) is conservatively set in the2

JCM_ID_AM024_ver01.0
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following manner to conservatively calculate reference emissions and ensure the net emission
reductions.
1. The estimated shaft power of the reference blower i during the period p (SPRE,i,p) is
selected from the performance table of the blower i with the calculated daily dischargepressure of the reference blower i during the period p (PSRE,i,p) and the calculated
rotations per minute (RPM) of the reference blower i during the period p (RPMRE,i,p). The
performance table of the blower i is provided by manufacturer of the blower i.
ܵܲோா,௜,௣ = ݂ோா ൫ܲܵோா,௜,௣ , ܴܲ‫ܯ‬ோா,௜,௣ ൯
SPRE,i,p: Estimated shaft power of the reference blower i during the period p [kW]PSRE,i,p: Calculated daily discharge pressure of the reference blower i during theperiod p [Pa (G)] (gauge pressure, and so forth)

RPMRE,i,p : Calculated RPM of the reference blower i during the period p [rpm]2. PSRE,i,p is calculated by the average daily discharge pressure of the project blower imonitored once a day during the period p (PSPJ,ave,i,p) divided by the ratio of dischargepressure change at the blower i (FPS,i). FPS,i is calculated by the highest daily dischargepressure of the project blower i monitored once a day during the parameter monitoring
period intpj which start after completion of aerator installation (PSPJ,high,i,intpj) divided by
the lowest daily discharge pressure of the reference blower i monitored once a day during
the parameter monitoring period intre before the aerator installation (PSRE,low,i,intre).
ܲܵோா,௜,௣ = ܲܵ௉௃,௔௩௘,௜,௣ ÷ ‫ܨ‬௉ௌ,௜‫ܨ‬௉ௌ,௜ = ܲܵ௉௃,௛௜௚௛,௜,௜௡௧௣௝ ÷ ܲܵோா,௟௢௪,௜,௜௡௧௥௘
PSPJ,ave,i,p: Average daily discharge pressure of the project blower i during theperiod p [Pa (G)]FPS,i: Ratio of discharge pressure change at the blower i [-]PSPJ,high,i,intpj : Highest daily discharge pressure of the project blower i during theparameter monitoring period after completion of aerator installation[Pa (G)]
PSRE,low,i,intre: Lowest daily discharge pressure of the reference blower i during theparameter monitoring period before the aerator installation [Pa (G)]If the project blower i is replaced at the time Tp,change during the period p, emission

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reductions during the time Tp,start, which is the start time of the period p, and Tp,change arecalculated with PSPJ,ave,i,p which is monitored from Tp,start to Tp,change. Emission reductions
after Tp,change are calculated based on PSPJ,ave,i,p which is monitored after Tp,change to the end
time of the period p (Tp,end).
3. RPMRE,i,p is calculated from the average RPM of the project blower i during the period p(RPMPJ,ave,i,p) divided by the ratio of RPM change at the blower i (FRPM,i). FRPM,i means theratio of RPM change from the reference blower i to the project blower i at completion ofaerator installation and is provided by the manufacturer of pulley because RPM isassociated with specification of pulley. RPMPJ,ave,i,p is monitored by rotation speed meter
once a day during the period p.
ܴܲ‫ܯ‬ோா,௜,௣ = ܴܲ‫ܯ‬௉௃,௔௩௘,௜,௣ ÷ ‫ܨ‬ோ௉ெ,௜
FRPM,i: Ratio of RPM change at the blower i [-]RPMPJ,ave,i,p : Average RPM of the project blower i during the period p [rpm]4. The estimated shaft power of the project blower i during the period p (SPPJ,i,p) is selectedfrom the performance table of the blower i with the PSPJ,ave,i,p and RPMPJ,ave,i,p.
ܵܲ௉௃,௜,௣ = ݂௉௃ ൫ܲܵ௉௃,௔௩௘,௜,௣ , ܴܲ‫ܯ‬௉௃,௔௩௘,௜,௣ ൯
SPPJ,i,p: Estimated shaft power of the project blower i during the period p [kW]Note 1: The performance table of the blower i shows relationship among discharge pressure[Pa (G)], RPM [rpm] and shaft power [kW] of the blower i in tabular format.
Note 2: Default value of the parameter monitoring period is 1 week excluding exceptional
operation. The value of RPM of the blower i and depth of aeration pond(s) during theparameter monitoring period need to be the same as the value monitored before theinstallation of aerator. Monitored discharge pressure or RPM data on exceptional
operation, such as during maintenance of blower, black out, accident of blower or
aeration device etc., are excluded from data set for determining PSPJ,ave,i,p, PSPJ,high,i,intpj,PSRE,low,i,intre, and RPMPJ,ave,i,p.

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F.2. Calculation of reference emissions
The electricity consumption of the reference blower i during the period p (ECRE,i,p) is calculatedby the product of SPRE,i,p, the motor efficiency of the reference blower i (Hi) and OTRE,i,p. Since
Hi is common to the project blower i, reference emissions are calculated by following equation.

ܴ‫ܧ‬௣ = ෍ ቊ௜ܱܶோா,௜,௣ ܵܲோா,௜,௣
×× ‫ܥܧ‬௉௃,௜,௣ × ‫ܨܧ‬௘௟௘௖ ቋܱܶ௉௃,௜,௣ ܵܲ௉௃,௜,௣

REp: Reference emissions during the period p [tCO2/p]

OTRE,i,p: Operating time of the reference blower i during the period p [h/p]

OTPJ,i,p: Operating time of the project blower i during the period p [h/p]SPRE,i,p: Estimated shaft power of the reference blower i during the period p [kW]SPPJ,i,p: Estimated shaft power of the project blower i during the period p [kW]ECPJ,i,p: Electricity consumption of the project blower i during the period p[kWh/p]

EFelec: CO2 emission factor for consumed electricity [tCO2/kWh]

OTRE,i,p is calculated from OTPJ,i,p added by the stop time of the project blower i during
intermittent operation during the period p (ITPJ,i,p) since the reference blower(s) is(are) notallowed to run intermittently and needs to be run continuously for preventing clogging of poresin diffuser.
ܱܶோா,௜,௣ = ܱܶ௉௃,௜,௣ + ‫ܶܫ‬௉௃,௜,௣
ITPJ,i,p: Stop time of the project blower i during intermittent operation during theperiod p [h/p]G. Calculation of project emissions
Project emissions are calculated by following equation.

ܲ‫ܧ‬௣ = ෍൫‫ܥܧ‬௉௃,௜,௣ × ‫ܨܧ‬௘௟௘௖ ൯௜

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JCM_ID_AM024_ver01.0
Sectoral scope: 03PEp: Project emissions during the period p [tCO2/p]

ECPJ,i,p: Electricity consumption of project blower i during the period p [kWh/p]

EFelec: CO2 emission factor for consumed electricity [tCO2/kWh]

H. Calculation of emissions reductions
Emission reductions are calculated as the difference between the reference emissions andproject emissions, as follows:

ER p = RE p - PE p
ERp: Emissions reductions during the period p [tCO2/p]

REp: Reference emissions during the period p [tCO2/p]

PEp: Project emissions during the period p [tCO2/p]

I. Data and parameters fixed ex ante
The source of each data and parameter fixed ex ante is listed as below.
Parameter
EFelecDescription of data
CO2 emission factor for consumed electricity.

Source[Grid electricity]
The data is sourced from

When project blower consumes only grid “Emission

Factorsofelectricity or captive electricity, the project Electricity

Interconnection

participant applies the CO2 emission factor Systems”, National Committee
respectively.

on

CleanDevelopment

Mechanism (Indonesian DNA
When project blower may consume both grid for CDM), based on data
electricity and captive electricity, the project obtainedbyDirectorate

participant applies the CO2 emission factor General of Electricity, Ministrywith lower value.

ofEnergyand

MineralResources, Indonesia, unlessotherwise instructed by the[CO2 emission factor]

Joint Committee.

For grid electricity: The most recent value
available from the source stated in this table at [Captive electricity]6JCM_ID_AM024_ver01.0
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the time of validation

For the option a)Specification of the captive

For captive electricity, it is determined based poweron the following options:generation

systemprovided by the manufacturer(ηelec [%]).

a) Calculated from its power generation CO2 emission factor of theefficiency(ηelec[%])obtainedfrom fossil fuel type used in the

manufacturer’s specification

captivepower

generation

The power generation efficiency based on system (EFfuel [tCO2/GJ])
lower heating value (LHV) of the captive
power

generation

systemfromthe For the option b)

manufacturer’s specification is applied;‫ܨܧ‬௘௟௘௖ = 3.6 ×Generated

100× ‫ܨܧ‬௙௨௘௟ߟ௘௟௘௖andsupplied

electricity by the captive power
generation

system(EGPJ,p[MWh/p]).

b) Calculated from measured data

Fuel amount consumed by theThe power generation efficiency calculated captive

powergenerationfrom monitored data of the amount of fuel system(FCPJ,p[massorinput for power generation (‫ܥܨ‬௉௃,௣ ) and the volume/p]).

amount of electricity generated ( ‫ܩܧ‬௉௃,௣ ) Net calorific value (NCVfuelduring the monitoring period p is applied. The [GJ/mass or volume]) and CO2

measurement is conducted with the monitoring emission factor of the fuelequipment to which calibration certificate is (EFfuel [tCO2/GJ]) in order ofissued

byanentity

accredited

under preference:national/international standards;‫ܨܧ‬௘௟௘௖ = ‫ܥܨ‬௉௃,௣ × ܰ‫ܸܥ‬௙௨௘௟ × ‫ܨܧ‬௙௨௘௟ ×Where:1) values provided by the fuel1‫ܩܧ‬௉௃,௣

supplier;
2) measurement by the project
participants;ܰ‫ܸܥ‬௙௨௘௟ : Net calorific value of consumed 3) regional or national default
fuel [GJ/mass or volume]

values;

4)

IPCC

default

valuesprovided in tables 1.2 and 1.4
Note:of Ch.1 Vol.2 of 2006 IPCC

In case the captive electricity generation Guidelines on National GHG
system meets all of the following conditions, Inventories. Lower value isthe value in the following table may be applied.
applied to ‫ܨܧ‬௘௟௘௖ depending on the consumed

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fuel type.
[Captive electricity with diesel
・ The system is non-renewable generation fuel]CDM approved small scale
system・ Electricity generation capacity of the methodology: AMS-I.A.
system is less than or equal to 15 MW[Captive electricity with natural
fuel type‫ܨܧ‬௘௟௘௖

Dieselfuel

Natural gas

0.8 *10.46 *2gas]
2006

IPCC

Guidelineson

National GHG Inventories forthe source of EF of natural gas.
CDM

Methodologicaltool*1 The most recent value at the time of "Determining the baseline
efficiency of thermal or electric
validation is applied.
*2 The value is calculated with the equation in energy generation systemsthe option a) above. The lower value of default version02.0" for the default
effective CO2 emission factor for natural gas efficiency for off-grid power(0.0543tCO2/GJ), and the most efficient value plants.
of default efficiency for off-grid gas turbine
systems (42%) are applied.
PSRE,low,i,intre

Lowest daily discharge pressure of theDischarge pressure isreference blower i during the parametermonitored by pressure gaugemonitoring period intre before the aerator

installed at discharge air pipe ofinstallation [Pa (G)]the blower i. PSRE,low,i,intre needs
to be monitored before thePSRE,low,i,intre is selected from the daily data

aerator installation.

which is monitored once a day during theparameter monitoring period before the aerator
installation.
PSPJ,high,i,intpj

Highest daily discharge pressure of the project

Discharge pressure is measured

blower i during the parameter monitoringby pressure gauge installed atperiod intpj after completion of aerator

discharge air pipe of the blower

installation [Pa (G)]i. PSPJ,high,i,intpj needs to bemonitored just after completion

PSPJ,high,i,intpj is selected from the daily data of aerator installation.
which is monitored once a day during theparameter monitoring period which start after8

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completion of aerator installation.
FPS,iRatio of discharge pressure change at theFPS,i is calculated byblower i [-]PSPJ,high,i,intpj divided by
PSRE,low,i,intre.

FRPM,i

Ratio of RPM change at the blower i [-]FRPM,i is provided by themanufacturer of pulley or
calculated from the diameter ofpulleys of the project/reference
blower i.

History of the document
Version01.0

Date
17 September 2020

Contents revisedElectronic decision by the Joint Committee
Initial approval.

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