The document discusses various challenges and considerations around accurately accounting for carbon emissions from buildings and electricity production methods. It touches on the need for standardized approaches and boundaries to avoid double counting, the sensitivity of different methods to accounting assumptions, and debates around how to appropriately assign emissions factors across supply chains and energy grids.

1. Questions concerning the Carbon Accounting of Buildings Heriot Watt Carbon Accounting Conference 11 th March 2009 Sue Roaf Heriot Watt University & Robert Cohen, Technical Director, ESD Camco See: www.carboncounting.co.uk

2. Stern review, Oct 2006 Source: Robert Cohen

3. Source: Ed Mazria of Mazria Inc. Odems Dzurec We must decarbonise buildings U.S. Energy Consumption Slide courtesy of Jesse Hensen, AIA, and Amy Hoagberg, CEM, Kyocera Solar & Don Aitken

4. Building energy efficiency retrofit costs £/tonne lifetime CO 2 100 0 200 300 Source: Robert Cohen

5. Cost of household energy in different worlds Extreme refurbishment: demand cut by two thirds Demand stays same Gas Electricity 2.7 13 2.9 4.6 22 14 18 66 Source: Robert Cohen

6. Source: Robert Cohen

7. Carbon Dioxide Emissions will include: Probably the most ‘correct’ approach is to split the scores into four categories: - Direct and measurable - Indirect, pro-rated on the bases of purchases - Indirect, not pro-rated and attributed to the industrial sectors - Fixed infrastructure, not pro-rated and attributable to government policy . Peter Harper, Centre for Alternative technology DIRECT EMISSIONS 34% HOUSE ENERGY 19.5% TRANSPORT ENERGY 14.5% INDIRECT PRO RATA EMISSONS 51% INDIRECT INFRASTRUCTURAL EMISSONS 15%

11. How to Calculate a Carbon Footprint Source: Robert Cohen

14. The roots of building energy consumption Asset Control & management Asset Control & management Source: Bill Bordass Total energy use per m 2 (primary or CO 2 equivalent) Lighting kWh/m 2 Efficiency (W/m 2 )/100lx Hours of use Effective hours/yr Management factor Vent rate (l/s)/ m 2 Ventilation kWh/m 2 Ventilation W/m 2 Efficiency W/(l/s) Effective hours/yr Management factor Hours of use Other uses A B B D F G H C D E F G H Light level Lux E Lighting W/m 2 C

15. Policy map: using EPCs and DECs to count direct carbon emissions from buildings Source: Robert Cohen, ESD

16. Display Energy Certificates for buildings Headline indicator Year-on-year improvement Additional technical details in fine print CO 2 emissions tonnes/year

18. Carbon Footprint Analysis as part of the design process of construction projects. Michael Purkiss Graduate Engineer Dunedin House 25 Ravelston Terrace Edinburgh EH4 3TP

20. The what works palette of RENs Source: njsolar

21. Wind – It works and is available on site House height 8m 400W turbine Electricity provision: 20% of a household Height: 2m Cost: £1500-2000 6kW turbine Electricity provision: 3.5 houses or 20% of a primary school Height: 9m Cost: £15-18k 220kW turbine Electricity provision: 85 houses or 5 primary schools Height: 36m Cost: £550-700k 1.5MW turbine Electricity provision: 1200 houses or 75 primary schools Height: 65m Cost: £1-1.5 million

26. The Aim Of The Project To develop a Carbon Footprint calculation methodology suitable for use in the design stage of construction projects.

32. Source: Environment product Declaration of electricity from Torness Nuclear Power Plant by AEA Technology Torness Life Cycle CO 2 Emissions The same technique was used for coal and wind energy: Based on typical UK coal plant data Based on Lewis Wind Farm project data & Danish data

35. The current method of CO 2 accounting is to calculate the CO 2 emissions using the an emission factor for complete combustion of the fuel (CO 2 /J) and then apply the efficiency of combustion or electrical generation process EF = EF f *  This allows, for instance nuclear generating capacity to be computed as zero carbon electricity i.e. EF f = 0 Notes from Andrew Peacock on the energy mix.. Source: Andrew Peacock

36. A central question that should therefore be asked is whether the total CO 2 emissions associated with the delivery of the energy that provides the ultimate service (i.e. heat or electricity) should be assigned to its production EF = (EF f *  +EE f This would therefore include mining of uranium in Australia and subsequent transportation and could also include storage of radioactive waste after use. It could also include the mining of coal in Russia or South Africa and its subsequent transportation Source: Andrew Peacock

37. Where the UK gets its Coal from – Imports ? Source: Andrew Peacock

38. Where the UK gets its Coal from Source: Andrew Peacock

39. A further complication arises with assigning emission factors to electricity consumption. This can be summarised as: The fuel mix used to generate electricity on the national grid varies with time. This variation occurs for the existing network at a minutely, daily and seasonal level In the future it is dependant on decarbonisation of the grid – what technologies and when Source: Andrew Peacock

40. The way the grid operates to maintain supply and demand balance is that fossil fuel plants are kept in a state of readiness to allow them to come on stream to meet load perturbations. This has an impact on CO 2 emissions: If the energy saving technology that is being investigated increases perturbations on the grid then this may therefore result in both an increase a reduction in network scale CO 2 emissions. The saving in CO 2 emissions is therefore net not gross Unless the energy saving technology can be controlled in such a manner to prevent exacerbation of load perturbations There is an absence of certainty

41. It is essential that carbon counting is done properly. A decision that one number is larger than another may set off a whole train of policy action. Just as the ‘financial engineering’ of a wind farm project may be as important as the nuts and bolts, so it will be with serious carbon counting. The importance of getting the right numbers and accounting procedures Bob Everett: Open University The problem seems to be to get the numbers to lie down on the paper and stop wriggling.

42. What we need is a Carbon Accounting Network for Buildings and Cities

43. “ What we need is an Institute of Carbon Accounting to sort these Issues out and validate methodologies” Colin Challen MP Chair, All Party Parliamentary Climate Change Group Holyrood Carbon Accounting Conference 29 th April 2008.