Full Document Text
Microsoft Word - 110531_1003_402-1183-00004_UserManual_Rev3_Final.docx
Greenhouse Gas Calculator for Municipal Waste (GLA80061)
User Manual
SLR Ref: 402-01183-00004
May 2011
Version: Rev 3
Greater London Authority i 402.01183.00004
GHG Calculator for MSW May 2011
SLR
T:\Projects\402\1183 - Greater London Authority\00004 - Greenhouse Gas Calculator for Municipal Waste\Tech\WS\Wking\110531_1003_402-1183-
00004_UserManual_Rev3_Final.docx
CONTENTS
1.0 BACKGROUND ........................................................................................................... 1
2.0 PURPOSE AND USE OF THE GHG CALCULATOR .................................................. 2
3.0 THE GHG CALCULATOR ........................................................................................... 4
3.1 The EPS and Carbon Intensity Floor ............................................................... 4
3.2 LCA and System Boundary of the GHG Calculator ........................................ 5
3.3 Model Design .................................................................................................... 6
3.4 GHG Calculator Overview ................................................................................ 7
3.5 Data Entry Guidelines ....................................................................................... 9
3.6 Source of Greenhouse Gas Data ................................................................... 10
3.7 Consistency of GHG Models .......................................................................... 10
4.0 QUICK REFERENCE GUIDE ..................................................................................... 11
5.0 FREQUENTLY ASKED QUESTIONS ........................................................................ 12
5.1 How do I use my own municipal waste composition? ................................. 12
5.2 How do I incorporate facility specific technology parameters? .................. 12
5.3 Which co-mingled collection type should I use? .......................................... 12
5.4 Do I have to record transport details if I am not going to include
transportation impacts in the results? .......................................................... 13
5.5 My distance data is in miles, how can I quickly convert it to kilometres? .. 13
5.6 How do I record more than 10 destinations for one material stream? ........ 13
5.7 Do I need to record rejects from residual treatment facilities? ................... 13
5.8 There is an error check in my worksheet, what should I do? ...................... 13
5.9 Can I add comments to my data? .................................................................. 13
5.10 How do I compare multiple scenario results? .............................................. 13
5.11 How is reuse accounted for in the model? ................................................... 14
5.12 How is waste reduction accounted for in the model? .................................. 14
5.13 How much of the calculator has to be completed? ...................................... 14
5.14 I am a WCA, which elements of the GHG Calculator should I complete? ... 14
5.15 I am a WDA, which elements of the GHG Calculator should I complete? ... 15
5.16 What data has been used for energy mix and carbon emissions per kWh?
16
6.0 CLOSURE .................................................................................................................. 17
APPENDICES
Appendix A Quick Reference Guide
Greater London Authority 1 402.01183.00004
GHG Calculator for MSW May 2011
SLR
1.0 BACKGROUND
The Mayor is preparing a new Municipal Waste Management Strategy which will include
policies to contribute to the reduction of greenhouse gas emissions. Policies will also seek to
exceed landfill directive and recycling targets set out in the UK Waste Strategy 2007. The
GLA, through earlier consultancy services, has developed a lifecycle assessment of the
current greenhouse gases emissions associated with waste management activities in
London and subsequently developed a projected lifecycle greenhouse gas emissions
performance standard (EPS) for London to work towards. In meeting the EPS, waste
authorities will need to ensure their municipal waste management activities (all stages from
collection to final disposal) collectively meet the agreed lifecycle greenhouse gas
performance standard, or that there are steps in place to meet the standard in the near
future.
The Mayor wishes to avoid placing additional financial burden on the waste authorities
through a requirement to procure the WRATE tool, thus the current project has resulted in
development of a GHG Calculator which will be made available online for free to the waste
authorities. This approach will minimise costs for the waste authorities and ensure
consistency in greenhouse gas emission reporting in London.
Greater London Authority 2 402.01183.00004
GHG Calculator for MSW May 2011
SLR
2.0 PURPOSE AND USE OF THE GHG CALCULATOR
The Greenhouse Gas Calculator has been commissioned by the GLA to assist Local
Authorities in assessing the greenhouse gas emissions associated with the procurement of
new waste services. The tool is designed to allow Authorities to test different waste
management options. The GLA will complete its own EPS review on an annual basis to
assess whether activities are in conformity with the Mayor’s Municipal Waste Strategy.
The GHG Calculator has been designed to be a flexible tool which can be used in a number
of situations, and assess a number of different elements of the waste stream. In summary,
there are 3 options for data inputting:
• Option A - Quick Estimator. To use the calculator to develop a quick estimate of
greenhouse gas emissions associated with a waste management system. Enter
tonnage data only, no transport distances or vehicles required, utilise the available
default technology types;
• Option B – Intermediate Model. As above, but include the vehicles and distance
data (can use default distances or user entered distance figures);
• Option C – Detailed Model. As above, but include User Entered technology
parameters for the residual treatment technologies. You will need to have a good
understanding of the technology mass and energy balances to create the user
entered technology parameters.
Mode of
Operation Ton
na
ge
da
ta
Ve
hic
les
an
d
Di
sta
nc
es
Us
er
en
ter
ed
tec
hn
olo
gy
pa
ra
me
ter
s
Table numbers to complete
A) Quick
Estimator checkbld
1. Input_MSW:
1.1 Modelled MSW Compositions
2. Input_Recycling
2.1 Kerbside recycling collection
2.1a Kerbside co-mingled recycling collection
2.1b MRF Reject Rate
2.2* Kerbside recyclables to first destination
2.3* Kerbside recyclables onward movements
2.4 HWRC recyclable materials
2.6 Bring site recyclables
3. Input_Organics
3.1 Kerbside collected organics
3.2* Kerbside organics first destination
3.3* Kerbside organics final destination
3.4 HWRC organics
3.5 HWRC organics onward movement
3.6 Gardens and Parks Organics
3.7* Gardens and parks organics first
destination
3.8 Gardens and parks organics onward
movement
Greater London Authority 3 402.01183.00004
GHG Calculator for MSW May 2011
SLR
Mode of
Operation Ton
na
ge
da
ta
Ve
hic
les
an
d
Di
sta
nc
es
Us
er
en
ter
ed
tec
hn
olo
gy
pa
ra
me
ter
s
Table numbers to complete
4. Input_Residual
4.1 Residual Waste Qunatity and Composition
(check)
4.2 Source and Quantity of Residual Waste
4.3* Kerbside residual collection
4.4* Kerbside residual onward movement
4.6* HWRC residual services onward
movement
4.8* Other residual waste first destination
4.9* Other residual waste onward movement
B)
Intermediate
Model
checkbld checkbld
All tables included in ‘Quick Estimator’ above,
with the addition of vehicle and distance
details.
C) Detailed
Model checkbld checkbld checkbld
All tables including Residual Technology
Parameters as appropriate to give a more
accurate estimation.
Optional
The ability to assess the impact of waste
reduction and waste re-use is factored into
worksheet 6. Output_Results. These options
are currently for Authority information only,
these activities will be counted towards the
EPS performance when approved emission
factors are available.
* – enter quantity and destination details only.
The GHG Calculator is available for Authorities to utilise in Option A, B or C. The GHG
Calculator is a resource for Authorities to determine whether a waste disposal contract
meets the Mayor of London’s carbon intensity floor or as an alternative to WRATE to
determine how waste activities perform against the Mayor’s emissions performance
standard.
Greater London Authority 4 402.01183.00004
GHG Calculator for MSW May 2011
SLR
3.0 THE GHG CALCULATOR
3.1 The EPS and Carbon Intensity Floor
The output from the GHG Calculator is the estimated emissions of greenhouse gases
(measured in tonnes of carbon dioxide equivalent) based on the waste management system
and processes defined by the user.
The tool also determines whether the scenario meets the EPS and Carbon Intensity Floor;
these two metrics are briefly summarised below:
Metric Purpose and inclusions Target value(s)
Emissions
Performance
Standard
(EPS)
Measures the impacts of the waste management
system (excluding containers) and divides the
greenhouse gas emissions by the tonnage of waste
managed.
-0.13 tCO2e / t waste
in 2015 reducing to
-0.24 tCO2e / t waste
in 2031
Carbon
Intensity
Floor
Measures the direct burden emissions associated
with generating energy from residual and organic
waste. The carbon intensity floor assesses the
emissions created from the combustion and
anaerobic digestion of waste to produce a kWh of
energy.
≤ 400 gCO2e / kWh
During the consultation of the draft Mayor’s Waste Strategy the GLA published a report
explaining the EPS and Carbon Intensity Floor and how they have been derived; copies of
these reports are available at the following links:
http://www.london.gov.uk/sites/default/files/GLA001MWS%20APPENDIX%204b.pdf
http://www.london.gov.uk/sites/default/files/GLA001MWS%20APPENDIX%204b%20cont%2
7d.pdf
The above reports have recently been updated, and will be accessible from the GLA
website. All figures utilised in this guidance document and the GHG Calculator are derived
from the revised EPS reports.
The GHG Calculator has been designed to allow the GLA to update the EPS and Carbon
Intensity Floor values should the current figures be revised in the future. The current EPS
figures are presented below:
Year EPS (t CO2e / t waste)
2015 -0.13
2020 -0.19
2031 -0.24
Greater London Authority 5 402.01183.00004
GHG Calculator for MSW May 2011
SLR
The Carbon Intensity Floor is currently set at 400 gCO2e / kWh.
A new version of the GHG Calculator will be uploaded to the GLA website should the EPS,
Carbon Intensity Floor or other parameters be updated. Users should check the GLA
website and download the latest version of the GHG Calculator prior to undertaking any
assessments.
3.2 LCA and System Boundary of the GHG Calculator
Life cycle assessment techniques measure the environmental and economic costs and
benefits of products and activities (in this case waste) at every stage of its existence, from
production to final disposal. Such techniques can provide a basis for making strategic
decisions on the ways in which particular waste in a given set of circumstances can be most
effectively managed, for example to reduce costs or greenhouse gas emissions from waste
activities (definition from the Mayor’s Waste Strategy).
The GHG Calculator measures the environmental benefits and impacts associated with the
so-called greenhouse gasses which are known to contribute to global warming. In waste
management, the main greenhouse gasses of concern are carbon dioxide, methane and
nitrous oxides. A system boundary diagram is presented in Figure 3-1 below.
Figure 3-1
System Boundary Diagram for GHG Calculator
The GHG Calculator includes the following elements:
• Transportation from route end points to facilities or intermediate facilities (optional);
• Activities at intermediate facilities;
• Transportation from intermediate facilities to treatment facility/reprocessor (optional);
• Activities at the reprocessor or treatment facility;
• Benefits associated with the avoidance of primary material extraction;
• Benefits associated with avoided fossil fuel use to generate electricity and heat;
• Onward transportation movement of SRF outputs and rejects from treatment facilities
for final management (optional)
• Benefits associated with waste reduction and re-use (note: currently optional and
advisory only. Will be included as part of EPS once approved emissions factors are
available.).
Greater London Authority 6 402.01183.00004
GHG Calculator for MSW May 2011
SLR
A number of transportation elements of the data input are optional depending on how the
user intends to use the model and its results (see those elements noted as optional above).
Where transportation is included in the calculator the following transport system boundaries
apply; these transport inclusions are consistent with the revised EPS and latest version of
the London Plan1:
Waste
Stream
Included Excluded
Recyclables • Transportation up to the last step before material sent for
reprocessing.
• The calculator allows kerbside
recyclables to be transported
to two intermediate facilities
and HWRC/Bring Site
recyclables to be transported
to one intermediate facility
before reprocessing.
• Transportation from final
intermediate facility to
reprocessing.
• Onward transportation of rejects
from intermediate
facilities/MRFs.
Organics • All transportation to the gate of the treatment facility, including
to any intermediate facilities.
• Onward transportation of
compost/digestate output from
treatment facility.
Residual • All transportation to gate of treatment facility, including to
any intermediate facilities.
• Transportation of SRF and
rejects from pre-treatment
(MHT/MBT/ Dirty MRF) to
secondary thermal treatment
and landfill.
• Onward transportation of
recyclables from pre-treament to
reprocessing.
The carbon impacts of containers (bins, bags and boxes) utilised to store waste and
recyclables prior to collection are outside the scope of the GHG calculator.
3.3 Model Design
The GHG Calculator is designed to give flexibility to users, as well as giving flexibility to the
GLA by allowing changes to background assumptions to be made. This means that as new
information becomes available (e.g. new carbon data, updated waste composition studies)
the tool can be updated, enabling output results to reflect the most up to date information
available.
Although the GHG Calculator is designed to be flexible for the user to allow data input for a
range of services, there are certain assumptions which must be fixed to ensure consistency.
It is proposed that if issuing a request to Authorities’ for completed GHG Calculator
scenarios that a list of fixed assumptions be issued and that these assumptions are adhered
to by all parties. Further information on this issue is provided in Section 3.7.
1 Mayor of London (2011) The London Plan: Spatial Development Strategy for Greater London –
Consultation Draft Replacement Plan, October 2009
Greater London Authority 7 402.01183.00004
GHG Calculator for MSW May 2011
SLR
The GHG Calculator has been designed with ease of use in mind. As the GHG Calculator
may be used infrequently during procurement exercises, it has been designed to be clear,
easy to complete, with comprehensive in-model instructions and hints to assist the user in
completing the model.
The model is split into a number of data input sheets, and one output results sheet.
Hyperlinks are used throughout the model to help navigate between different input sheets
and locate key parameter options. Further details are provided in Section 3.4.
3.4 GHG Calculator Overview
The overview diagram below (Figure 3-2), which can be found in the ‘Overview’ worksheet of
the GHG Calculator, shows the layout of the tool. Each box represents a worksheet within
the calculator; the boxes are colour coded for ease of reference and navigation as follows:
Figure 3-2
Overview of GHG Calculator
The blue filled boxes are worksheets which require data inputs from local authority users.
These worksheets record data relating to MSW quantity and composition, as well as tracking
recycling, organics and residual waste from collection to final disposal.
The boxes which have a white fill and a blue border are the Carbon modules. These
worksheets contain the greenhouse gas emission data relating to each element of the waste
management process.
Greenhouse gas emission data has largely been obtained from the WRATE software, with
other sources of information and calculations supplementing the WRATE data to enable an
accurate GHG Calculator. A number of the Carbon module worksheets contain options to
utilise greenhouse gas data from different sources; in these cases a default data set has
been entered and there is provision of a space for an additional data set which can be
entered by the GLA. Where appropriate there is also a space allocated for a user entered
data set. As mentioned previously (and discussed in Section 3.7), a list of fixed assumptions
will be issued by the GLA as required.
The GHG Calculator combines the input data entered by the local authority user, through a
number of intermediate calculations and the carbon module data to generate estimates of
the greenhouse gas emissions of each stage of the waste management process.
Greater London Authority 8 402.01183.00004
GHG Calculator for MSW May 2011
SLR
Calculation methods in the tool are fixed and cannot be changed by the user. This ensures
that all scenario tests produce accurate and consistent results.
The following table provides a brief overview of the contents of each worksheet contained
within the GHG Calculator.
Table 3-1
Summary Contents of each Worksheet
Worksheet name Brief description of contents
Overview Graphical summary of the worksheets contained within the GHG
Calculator. All boxes are hyperlinked to aid navigation.
This worksheet provides a space to list the project title, assumptions,
date and name/organisation of the model creator.
Users must select whether they will include or exclude transportation in
the scenario.
MSW Contains information relating to composition, calorific value and carbon
contents (fossil and biogenic) of the material components.
Users must enter the assessment year, quantity and composition of the
MSW stream.
Recycling
Services
Input data sheet for all recycling related waste services. Worksheet is
split into separate areas for kerbside, HWRC and Bring site services.
Organics Waste
Services
Input data sheet for all organic related waste services. Worksheet is
split into separate areas for kerbside, HWRC and Parks and Gardens
services.
Residual Waste
Services
Input data sheet for all residual related waste services. Worksheet is
split into separate areas for kerbside, HWRC and Other residual waste
services.
Residual
Technology
Parameters
A number of technology types are available in the Residual Waste
Services worksheet to manage the residual waste stream. Users can
choose to manage the waste via the default technology parameters, or
if they have technology specific data available they can complete a
user defined technology choice (refer Section 2).
Transport Module Contains greenhouse gas emission data for the transportation of waste
materials.
Intermediate
Facility Module
Contains greenhouse gas emission data for the intermediate
management of waste materials (e.g. HWRCs, waste transfer stations,
MRFs).
Recycling Module Contains greenhouse gas emission data and options for the recycling
of waste materials.
Organic
Treatment
Contains greenhouse gas emission data for the treatment of organic
waste materials.
Greater London Authority 9 402.01183.00004
GHG Calculator for MSW May 2011
SLR
Worksheet name Brief description of contents
Module
Residual
Treatment
Module
Contains greenhouse gas emission data for the treatment of residual
waste materials.
Energy Module Contains the DECC forecasted energy mix, and the carbon emission
factors for different energy generation technologies (e.g. coal, gas,
renewable etc) to give ‘standard’ energy offset values. Also allows
selection of GLA override offset figures for electricity and heat
generation. The model currently uses a value of 0.4 kgCO2e/kWh to
offset electricity and heat generated from residual waste treatment and
anaerobic digestion.
Model Results This worksheet presents the results of the scenario based on the user
inputted data and the choice of greenhouse gas emission data sets.
Absolute results are presented, high level analysis of the results is
included, and the worksheet details whether the Emissions
Performance Standard and Carbon Intensity Floor have been
achieved.
This worksheet also presents the opportunity for the user to assess a
number of scenarios side by side and look at the differences in results.
3.5 Data Entry Guidelines
The GHG Calculator Model has been colour coded to assist with data input and to help
guide users around the model.
A blue cell indicates a selection is required from a drop-down list of options.
Where drop down cells are highlighted green these menu choices must be set according to
GLA instructions. These parameters must be used consistently by users to ensure
comparable models are generated.
Grey cells require data input from the user and white cells allow for additional user
comments to be made where required.
Light yellow coloured cells contain fixed or calculated values and text. These cells should
therefore not be altered by the user.
Greater London Authority 10 402.01183.00004
GHG Calculator for MSW May 2011
SLR
3.6 Source of Greenhouse Gas Data
As described above, the majority of the greenhouse gas emission data is derived from the
WRATE Version 2 software. This information is supported with data from other sources, and
details of this data are listed below in Table 3-2.
Table 3-2
Greenhouse Gas Data Sources
Source of Greenhouse Gas Data
Transportation Based on per tonne km factors derived from WRATE V2.
Intermediate Facilities Based on per tonne factors derived from WRATE V2.
Recycling Based on per tonne factors derived from WRATE V2.
Organics Based on per tonne factors derived from WRATE V2. Non-
WRATE data for output material and related offsets. DECC
figures for the energy offset factors (for AD only).
Residual Based on per tonne factors derived from WRATE V2. Material
component calculations for combustion emissions. DECC figures
for the energy offset factors.
Avoided Energy
Generation
DECC figures for the energy mix and emissions for different
energy generation sources.
The GHG Calculator has been developed with flexibility in mind, and as such there are
options for inserting and selecting alternative greenhouse gas emission factor data. The GLA
will provide users with information on which greenhouse gas data to use for the purposes of
GHG Calculator completion.
3.7 Consistency of GHG Models
The background assumptions and data sources selected can have a considerable impact on
the output results of the calculator. The GHG Calculator includes the ability to select from
multiple data sources; this option was included to ensure the GLA had access to a flexible
GHG Calculator for future years. However to avoid users selecting different data sources,
the GLA will issue a register of factor settings that must be utilised. This will include
assumption settings for:
• Waste composition (if requires fixing);
• Source data for Carbon Content of waste;
• Source data for Calorific Value of waste;
• Energy Mix Data;
• Source data for Carbon Emissions from Energy Sources;
• Source data for the Carbon Factors relating to recyclables and organic outputs.
The settings issued by the GLA must be adhered to as requested. The GLA may request a
copy of the completed GHG Calculator file in order to review the assumption settings for
consistency and compliance.
Greater London Authority 11 402.01183.00004
GHG Calculator for MSW May 2011
SLR
4.0 QUICK REFERENCE GUIDE
The GHG Calculator has been designed to be easy to use and applicable to a broad range
of users. The tool incorporates comprehensive instructions, hints and tips throughout, thus
avoiding the requirement for detailed supporting User Manual. To support the users, a Quick
Reference Guide has been produced, this is presented below, with a full copy A4 PDF
included as Appendix A (which will allow users to print a copy of the Quick Reference
Guide). This quick reference guide should be used alongside the details in Section 2 to
direct users in the completion of the GHG Calculator.
Figure 4-1
GHG Calculator Quick Reference Guide
Greater London Authority 12 402.01183.00004
GHG Calculator for MSW May 2011
SLR
5.0 FREQUENTLY ASKED QUESTIONS
A series of frequently asked questions have been prepared to assist users of the GHG
Calculator. Please refer to these FAQs, in the first instance, to see if any problems can be
overcome before contacting the GLA.
5.1 How do I use my own municipal waste composition?
From the Overview worksheet click on the ‘MSW’ box coloured blue.
Complete cells K21:K35 with the user specific composition data.
Using the drop down list in cell C17, select User Entered Composition.
5.2 How do I incorporate facility specific technology parameters?
From the Overview worksheet click on the ‘Residual Technology Parameters’ box shaded
blue with a dashed blue border.
Use the ‘Go to table’ hyperlinks in column F to take you to the correct row for the specified
technology type. Scroll across to column AA to insert the technology parameter data.
Note: if the technology involves combustion or similar processing, only the total figures must
be completed. If a non combustion technology the waste distribution parameters must sum
to 100% for all material components (this can be checked in Column AK which will show
‘TRUE’ if 100%.
Return to the table in cells B10:E20 by clicking the ‘back to top’ hyperlink in column A, locate
the technology type and in column D select User defined parameters from the drop down
menu.
5.3 Which co-mingled collection type should I use?
If your authority collects co-mingled recycling this should be recorded under co-mingled in
the kerbside recycling materials table [Input_Recycling C25]. You should select one of the
seven collection scheme types for co-mingled recycling. The options reflect those used in
Waste Data Flow, presented in Figure 5-1 below:
Figure 5-1
Co-mingled collection types2
Use the collection type which best represents your collection service.
2 Waste Data Flow Guidance Manual: Entering Data. Available at:
http://www.wastedataflow.org/Documents/GuidanceManual/WDF-3%20Entering%20Data.pdf
Greater London Authority 13 402.01183.00004
GHG Calculator for MSW May 2011
SLR
5.4 Do I have to record transport details if I am not going to include transportation
impacts in the results?
If you are not assessing the greenhouse gas impacts of transportation in your model then
you do not need to record the transportation detail. The impacts of transportation are
currently included in the EPS boundary (as of revisions in May 2011).
Further instructions are located in the model within the ‘Hints’ boxes, these outline which
cells to complete. Please also refer to the transport system boundary table in section 3.2
above.
5.5 My distance data is in miles, how can I quickly convert it to kilometres?
When entering transportation data in to the GHG Calculator, all distances must be entered in
kilometres. If you need to convert miles to kilometres there is a conversion calculator at the
top of the overview sheet. A hyperlink at the top of each input sheet will take you directly to
the conversion calculator.
5.6 How do I record more than 10 destinations for one material stream?
If one material stream has been sent to more than ten destinations it may be necessary to
include an average distance to facilities. Where different modes of transportation are used,
use the vehicle which transports the largest proportion of your authority’s waste.
The estimation or averaging of trip distances is acceptable when completing the GHG
Calculator. Users should keep a note of any assumptions in the Overview sheet notes
section (F54).
5.7 Do I need to record rejects from residual treatment facilities?
No, you don’t need to record rejects when inputting your data. Rejects from facilities are
accounted for within the background calculations within the model. Therefore you do not
need to account for management of rejected waste from reprocessing/ treatment facilities.
Only record inputs to reprocessors and treatment facilities.
5.8 There is an error check in my worksheet, what should I do?
If one of the checks in your worksheet appears in red it indicates there is an error in your
data. Your waste arisings should always equal the amount of waste being managed. If a
check appears red a short description of the error should be provided; initially check through
the data to ensure no errors or double counting of tonnages has been made whilst inputting.
By selecting the cell with the check you can see exactly what the check relates to. You may
find it useful to use [F2] which identifies the source cells of the check.
5.9 Can I add comments to my data?
The GHG Calculator allows user comments in each input table to assist with ease of use and
clarity. You may want to record the name of the reprocessors here, or record whether any
estimations or assumptions have been made.
5.10 How do I compare multiple scenario results?
From the Overview worksheet click on the ‘Model Results’ box coloured green.
Scroll down the worksheet to row 129 onwards, you will see a blank table and further
instructions.
Greater London Authority 14 402.01183.00004
GHG Calculator for MSW May 2011
SLR
Once completed, the results are compared in the charts.
5.11 How is reuse accounted for in the model?
The WRATE tool currently accounts for re-use by removing the waste from the system and
assuming no burdens or avoided burdens are applied.
The GHG Calculator differs from the WRATE model by utilising recent data provided by
WRAP on the greenhouse gas emissions relating to waste prevention and the preparation of
materials for re-use.
It is assumed that re-used tonnages consist of Clothing (textiles), Furniture (assumed as
wood) and electrical items (assumed as WEEE – mixed). Users can utilise a default
compositional split between these materials or enter a user composition. The benefits are
calculated based on the tonnage of reuse and composition of reuse materials.
WRAP are currently completing a study on re-use; the information from this study can be
incorporated into the GHG Calculator when the study is published. The impacts of reuse are
not currently included in calculating the EPS, however they can be included within the GHG
Calculator for Local Authority information only.
5.12 How is waste reduction accounted for in the model?
Accounting for waste reduction is a complex issue; trying to separate the impacts of waste
reduction campaigns from other economic and behavioural changes is challenging, and
currently WRATE does not include a methodology to predict the benefits of waste reduction.
For the purposes of the GHG Calculator users have an option to enter a percentage waste
reduction which provides a revised absolute tonnage of CO2e for the scenario. This option is
located on the results sheet (cell C60), the reduction is applied across all elements of the
waste scenario modelled.
The waste reduction percentages and revised results are for information purposes only; the
reduction factors do not impact on the output results of the EPS or Carbon Intensity Floor.
This simplistic approach allows users to see the impact of waste reduction against the
absolute tonnage emissions of greenhouses gasses emitted.
5.13 How much of the calculator has to be completed?
Three Options (A to C) exist for completing data within the GHG Calculator; Option A
requires the bare minimum of data, with Option C requiring full completion of the model.
Refer to Section 2.0 of this User Manual to review the Options and data input requirements.
Also refer to the Quick Reference Guide in Appendix A.
5.14 I am a WCA, which elements of the GHG Calculator should I complete?
As a Waste Collection Authority, the following elements of the GHG Calculator should be
completed, and the model provided to the WDA (as required):
Greater London Authority 15 402.01183.00004
GHG Calculator for MSW May 2011
SLR
Worksheet Components to complete
MSW All
Recycling Kerbside collection (tonnages collected and transport to intermediate
facilities)
Bring banks (tonnages collected and transport to intermediate facilities)
Organics Kerbside collection (tonnages collected and transport)
Parks and Gardens (tonnages collected and transport)
Residual Kerbside collection (tonnages collected and transport)
Other residual (tonnages collected and transport)
Results If the GHG Calculator results are to feed into WDA results then only the
transport impacts should be reviewed. This avoids double counting of the
benefits associated with reprocessing of recyclables.
5.15 I am a WDA, which elements of the GHG Calculator should I complete?
As a Waste Disposal Authority, you can recreate the total combined WCA tonnage figures
(for kerbside, bring sites, parks and gardens and other residual waste) in a WDA model
(which includes HWRC wastes) and detail all onward movement / treatment of wastes.
Alternatively you can complete the WDA model (as outlined below) and complete the
separate WCA model(s) with the onward destination and treatment information. The addition
of the WCA models (excluding transport emissions to disposal points) and the WDA model
will provide the total results.
Worksheet Components to complete
MSW All
Recycling HWRC (tonnages and distances to intermediate facilities)
Organics HWRC (tonnages and distances)
Residual HWRC (tonnages and distances)
Results All impacts (ensure impacts from WCA transport and recycling are
accounted for).
Greater London Authority 16 402.01183.00004
GHG Calculator for MSW May 2011
SLR
5.16 What data has been used for energy mix and carbon emissions per kWh?
The GHG Calculator currently includes DECC sourced data for the energy mix forecasts3
and carbon impacts for different energy generation sources.4
These data sources and assumptions are included in the Energy Module worksheet (Rows
39 to 49 and Rows 53 to 63 respectively). The GLA can update the GHG Calculator as
revisions to the DECC projections or revised carbon emission quantities per kWh of
electricity generation are published. The model currently uses the DECC marginal energy
mix figures of 400gCO2/kWh to offset any electricity or heat generated by residual waste
treatment and anaerobic digestion.
3http://www.decc.gov.uk/assets/decc/White%20Papers/UK%20Low%20Carbon%20Transition%20Pla
n%20WP09/1_20090724153238_e_@@_lowcarbontransitionplan.pdf)
4 http://www.decc.gov.uk/en/content/cms/statistics/fuel_mix/fuel_mix.aspx
Greater London Authority 17 402.01183.00004
GHG Calculator for MSW May 2011
SLR
6.0 CLOSURE
The GHG Calculator has been designed to give flexibility to users, as well as giving flexibility
to the GLA by allowing changes to background assumptions to be made. This means that as
new information becomes available (e.g. new carbon data, updated waste composition
studies) the model can be updated, enabling output results to reflect the most up to date
information available.
Users should consider the information and FAQs contained within this User Manual, in
addition to the instructions, hints and tips within the GHG Calculator prior to contacting the
GLA for support.
Enquiries regarding this tool should be directed via e-mail to the GLA Project Manager
(larissa.bulla@gla.gov.uk).
Greater London Authority 18 402.01183.00004
GHG Calculator for MSW May 2011
SLR
APPENDIX A
QUICK REFERENCE GUIDE
GLA Greenhouse Gas Calculator Tool
- Quick Reference Guide
ii. Overview
Complete model set up text [F51:F56] and select whether to
include transportation in the model from drop down options in
F58.
1. Input_MSW
Enter assessment year and MSW total [C10 and C12].
Select Composition from the drop down options [C18] OR
input user composition [K23:K37] and select 'User entered
composition' .
Select a data source for Carbon content and Calorific Value
from the drop down options [C46 and C48]. Options are
shown in tables to the right [H52:L67 and N52:R67] , where
user entered data can also be inserted. Data for the selected
options is shown in the component characteristics table
[B52:F67].
2. Input_Recycling
Enter Recycling Service data (tonnages and recycling methods)
from Kerbside, HWRC and Bring Banks. Where recyclables are
collected co-mingled, select a composition type from 7
options., and an additional table [H13:L26] will show the
composition . The recycling methods need to be selected in
this table. MRF reject rate can be entered in Q16, otherwise
the default is used.
Transportation data is optional depending on selection made in
overview.
3. Input_Organics
Enter Organic Service data (tonnages and organic treatment
methods) from Kerbside, if collection is mixed the material
composition can be entered in G15:G17. Enter green waste
tonnages from HWRCs and Parks and Gardens.
Transportation data is optional depending on selection made in
overview.
4. Input_Residual
Enter Residual Service data from Kerbside, HWRC and other
sources. This includes tonnages and residual disposal /
treatment methods. Secondary treatment destination should be
entered for SRF/Fibre outputs from primary treatment where
applicable .
Transportation data is optional depending on selection made in
overview.
Recycling Module
This module specifies the carbon factors for
recyclables. Select the data source for carbon factors
[D11]. Options are shown in G13:L41, where user
entered data can also be inserted.
Energy Module
Select data source for electricity energy mix
assumptions from the drop down options [D13].
User energy mix can be entered in C40:C48. Select
data srouce for carbon factors from the drop down
options [D15]. A summary of the selected choices is
shown in the summary table [B19:D29].
5. Residual Technology Parameters
Select either generic or user defined parameters for
each technology type [D13:D22].
User defined data is entererd in the parameter
tables in Column AA:AJ.
6. Output_Results
This worksheet presents the results, a schematic of waste
movements , and indicates whether the EPS and Carbon
Intensity Floor targets have been met. . Before procedding
with results ensure all checks are 'OK' in the consistency checks
table [B8:F9]. Reuse can be accounted for by entering the
quantity of material reused in C16.
If Scenario comparison is required, enter results from multiple
models as pasted values in B128 to H143.
Organics Module
This module specifies the carbon offsets associated
with compost use. Select the data source for carbon
offsets in D24. Options are shown in H27:J28, where
user entered data can also be inserted.
