This document summarizes an ICARB energy workshop on carbon accounting in the power sector. ICARB aims to create transparent, consistent, and accurate rules for carbon accounting that can be used by policymakers, academics, environmental managers, and others. The workshop discussed various carbon accounting guidelines and methods, including those from ISO, the GHG Protocol, and Defra. It also covered topics like system boundaries, treatment of capital emissions, output metrics, LCA software, data sources, and uncertainty. Developing a standardized framework and accreditation process could help improve comparability between carbon accounting studies.

1. ICARB Energy Workshop
Carbon Accounting in the Power Sector
Chaired by:
Camilla Thomson, University of Edinburgh
Samuel Chapman, Heriot-Watt University

2. Who is the audience of ICARB?
ICARB will be used by anyone with involvement in
carbon accounting including:
• Policy makers
• Academics
• Environmental managers
• Environmental consultants
• Community groups
• Others?

3. What resources are available?
• PowerPoint Presentations from
conferences
• The ICARB blog
• Tools
• News
• The Fundamentals

4. ICARB: The Initiative for
Carbon Accounting
That said, now we need to
working to create a set be able to do this for each
of: sector
transparent, consistent and
accurate rules for carbon This work has been carried
accounting. out to an extent, can we tie
it together?

5. Current Guidelines and Practices
ICARB Energy Workshop

6. Carbon Accounting
Methods & Guidelines
• ISO 14040/44
MANUFACTURE &
• GHG Protocol
ASSEMBLY
• Defra Guidelines
OPERATIONS &
MATERIALS
EXTRACTION &
PROCESSING
MAINTENANCE
• Carbon Trust Standard
• Input-Output Analysis
WASTE
RECYCLING
DECOMMISSIONING &
DISPOSAL
• Fuel Mix Disclosure
• PAS 2050
• And more!

7. Comparison
• UNFCCC Whole electricity systems
• GHG Protocol considered
• Defra - Corporate Accounting, scopes
• ISO 14040/44 - Product life cycle, only one to
include Capital Emissions (CapEm)

8. MANUFACTURE &
ASSEMBLY
OPERATIONS &
MATERIALS MAINTENANCE
EXTRACTION &
PROCESSING
0.547kgCO2-e/kWh
WASTE
DECOMMISSIONING &
RECYCLING DISPOSAL

9. System Boundary
• Cradle-to-grave • CapEm and OpEm
– All LCAs include materials
• Physical boundary and transport
– The inclusion of emissions
• Boundary with nature associated with capital
– Change of land use? goods is optional –
implications for electricity
Image taken from Life cycle assessment of offshore and onshore sited wind power plants based on Vestas V90-3.0MW turbines, 2005 (Vestas Wind Systems
A/S, Randers, Denmark).

10. Output Unit
Micro-wind Turbine: Sensitivity to Location
kg CO2-e/kWh 1000
900
• Normalisation
Intensity (g CO2/kWh)
800
700
600
• What is a Person 500
400
Equivalent (EDIP)? 300
200
• How do we calculate
100
0
0 500 1000 1500 2000 2500 3000
lifetime power output? Annual Production (kWh/year)
Manchester (South West Edge) Portsmouth (North East Edge)
• All greenhouse gases or
Portsmouth (City Centre) Wick (South East Edge)
Wick (City Centre) Coal
Oil Natural Gas
Nuclear Hydro
just CO2? Solar PV

11. Discussion
• ISO 14040/44 • System boundary
• GHG Protocol • Cradle-to-grave
• Defra Guidelines • CapEm and OpEm
• Carbon Trust Standard • Unit
– kg CO2-e/kWh
• Input-Output Analysis
• Fuel Mix Disclosure
• PAS 2050
• Etc….

12. LCA Software, Data Sets and Uncertainty
ICARB Energy Workshop

13. Software
• Does software affect
results?
• Does software choice
affect assumptions?
• Software includes:
– GaBi
– SimaPro
– MS Excel
– CCalc
– Etc…
Chart taken from LCA Practitioners Survey 2011, Bluehorse Associates, 2011

14. Data Sources and Inventories
• User selection of data has
significant impact on
results
• Data quality requirements
– Age of data
– Geography
– Technology assessed
– Allocation method
– System boundaries
OTHER
LCA
• Validation? STUDIES

15. Uncertainty
• Scenario uncertainty
• Parameter uncertainty
• Model uncertainty
• Statistical uncertainty?
• Inputs, processing and outputs
Figure taken from Sovacool, B., 2008. Valuing the greenhouse gas emissions
from nuclear power: A critical survey. Energy Policy, 36(8), pp.2950-2963.

16. Discussion
• Software
• Data quality and validation
– Data from other studies

17. Developing a Standard Framework and Providing
Accreditation
ICARB Energy Workshop

18. Standard Framework?
“Does an ISO-standard settle the uncertainty problem for a decision-
maker, but not the scientist?”
Heijungs, R. & Huijbregts, M.A.J., 2004. A Review of Approaches to Treat Uncertainty in LCA
Table taken from Sovacool, B., 2008. Valuing the greenhouse gas emissions from
nuclear power: A critical survey. Energy Policy, 36(8), pp.2950-2963.

19. Standardised Definition Set
http://icarb.org/carbon-accounting-glossary/

20. Accreditation
• Demand?
• Comparability of studies
– Decision making
– Public relations
– Compliance
• Potentially combine with
review required by ISO
14040-44

21. Discussion
• Definitions List online
• http://icarb.org/carbon-
accounting-glossary/