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Carbon Accounting Buildings | Sue Roaf

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Carbon Accounting Buildings | Sue Roaf

  1. 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:
  2. 2. Stern review, Oct 2006 Source: Robert Cohen
  3. 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. 4. Building energy efficiency retrofit costs £/tonne lifetime CO 2 100 0 200 300 Source: Robert Cohen
  5. 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. 6. Source: Robert Cohen
  7. 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%
  8. 8. <ul><li>“ The total set of greenhouse gas emissions caused directly and indirectly by an individual, organisation, event or product” Carbon Trust 2007 </li></ul><ul><li>Different types of carbon footprint: </li></ul><ul><ul><li>Individual footprints </li></ul></ul><ul><ul><li>Organisational footprints </li></ul></ul><ul><ul><li>Event footprints </li></ul></ul><ul><ul><li>Product footprints </li></ul></ul>What is a Carbon Footprint? Source: Robert Cohen
  9. 9. CO 2 or CO 2 equivalent <ul><li>Six gases are controlled under the Kyoto protocol. CO 2 e expresses greenhouse gas emissions as the amount of CO 2 with the same global warming potential </li></ul>Source: Robert Cohen Greenhouse Gas Global Warming Potential Carbon dioxide (CO 2 ) 1 Methane (CH 4 ) 23 Nitrous oxide (N 2 O) 296 Sulphur Hexafluoride (SF6) 22,200 Perfluorocarbons (PFCs) 4,800 – 9,200 Hydrofluorocarbons (HFCs) 12 – 12,000
  10. 10. Organisational carbon footprints <ul><li>Define the boundaries (what you want to assess) </li></ul><ul><ul><li>Organisational boundary </li></ul></ul><ul><ul><ul><ul><ul><li>Control </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Equity share </li></ul></ul></ul></ul></ul><ul><ul><li>Operational boundary </li></ul></ul><ul><li>Collect the data </li></ul><ul><li>Calculate emissions and convert GHGs to CO 2 e </li></ul>Source: Robert Cohen
  11. 11. How to Calculate a Carbon Footprint Source: Robert Cohen
  12. 12. Standards and protocols <ul><li>World Business Council for Sustainable Development/World Resources Institute (2004) - the Greenhouse Gas Protocol . </li></ul><ul><li>ISO 14064 (2006) – Specification with guidance at the organisation level for quantification and reporting of greenhouse gas emissions and removals. </li></ul><ul><li>Sources for emissions factors : </li></ul><ul><li>Defra 2007. Guidelines to Defra’s greenhouse gas conversion factors for company reporting. </li></ul><ul><li>WBCSD website. </li></ul><ul><li>IPCC 2006. Guidelines for National Greenhouse Gas Inventories. </li></ul>Source: Robert Cohen
  13. 13. GHG Protocol – Strengths and Weaknesses <ul><li>Strengths </li></ul><ul><li>Clear guidance on process of emissions accounting and reporting </li></ul><ul><li>Sound principals defined: scope system can prevent double counting </li></ul><ul><li>Tried, tested and developed over years with wide consultation </li></ul><ul><li>Flexible approach – optional Scope 3 encourages reporting in steps </li></ul><ul><li>Links to financial accountancy – helps carbon be seen as ‘assets’ and ‘liabilities’ </li></ul><ul><li>Provision of tools for calculation, with tiered approach </li></ul><ul><li>Weaknesses </li></ul><ul><li>No requirement for verification </li></ul><ul><li>Scope 3 is optional: limited advice on avoiding double counting </li></ul><ul><li>No standard set of emission factors </li></ul><ul><li>‘ Well to wheel’ emissions not counted so difficult to report eg biofuel use </li></ul><ul><li>Tiered approach so some assessments based on primary data others estimated </li></ul><ul><li>Cross company comparisons difficult – no normalising and different scope </li></ul><ul><li>No standards for base year recalculation </li></ul><ul><li>No standard for materiality in verification </li></ul><ul><li>No guidance given on credits/offsets </li></ul>Source: Robert Cohen
  14. 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. 15. Policy map: using EPCs and DECs to count direct carbon emissions from buildings Source: Robert Cohen, ESD
  16. 16. Display Energy Certificates for buildings Headline indicator Year-on-year improvement Additional technical details in fine print CO 2 emissions tonnes/year
  17. 17. <ul><li>DECARBONISING BUILDINGS </li></ul><ul><li>CASE STUDY: The Sports Hall </li></ul><ul><li>The proposed sports halls is: </li></ul><ul><li>- 36 x 40mx 7m high, </li></ul><ul><li>- floor area of around 1440m2 . </li></ul><ul><li>- The currently preferred design includes: </li></ul><ul><li>- 15 Sprung Sports Floor </li></ul><ul><li>- Lighting should be Multi-Corso set between the badminton courts </li></ul><ul><li>- Heating system is a Continuous Black Tube radiant heating system. </li></ul><ul><li>- 160m2 sports storage equipment </li></ul><ul><li>- Full height glazed screen between corridor and sports hall </li></ul><ul><li>- Range of fixed equipment including basket ball goals, netball & badminton posts </li></ul><ul><li>- Side walls to be green or blue to meet badminton requirements </li></ul><ul><li>Top 3m of the 3 external walls are designed to include Kalwall Transluscent </li></ul><ul><li>cladding, an insulating, diffuse, light transmitting system that eliminates glare hot spots and shadows. </li></ul>
  18. 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
  19. 20. The what works palette of RENs Source: njsolar
  20. 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
  21. 22. <ul><li>CALCULATING THE COST BENEFITS OF THE SAVINGS: </li></ul><ul><li>Recommendation 3: Naturally ventilate the sports hall and eliminate the need for mechanical cooling and provision of fresh air. Removal of central ventilation plant and fans. </li></ul><ul><li>Electricity cost savings 34 kWh/m2/a saved by removal of mechanical ventilation system. = 1440 x 34 = 48960 kWh/a </li></ul><ul><li>CO2 savings 21.053 tonnes annum </li></ul><ul><li>cost savings 1440 x 34 x 5.5 = £2693 annum </li></ul><ul><li>Cost of measure removes c. -£15,000 from plant cost and adds the same for the opening Kalwal windows at the upper level. </li></ul><ul><li>Payback 0 years </li></ul><ul><li>Recommendation 4: Under floor heating with GSHP power in part with a wind turbine </li></ul><ul><li>Replace all air blown sports hall heating system with under-floor heating from a ground source heat pump with wind turbine giving zero energy heating for the hall. </li></ul><ul><li>Heating gas saved 307 kWh/m2/a = 1440 x 307 = 442080 kWh/a </li></ul><ul><li>CO2 savings 83.995 tonnes annum </li></ul><ul><li>cost savings 442080 x 2.7 = £11,936 annum </li></ul><ul><li>Cost of measure £100,000 </li></ul><ul><li>Payback 8.38years </li></ul>
  22. 23. RENEWABLE ENERGY GRANTS: The Low Carbon Buildings Programme - Stream 2B. ( ). <ul><li>Solar photovoltaics 50% </li></ul><ul><li>Biomass 35% </li></ul><ul><li>Ground source heat pumps 35% </li></ul><ul><li>Wind turbines 30% </li></ul><ul><li>Solar thermal 30% </li></ul>
  23. 25. Recommendations: <ul><li>High the thermal efficiency of the structure of the sports hall through the use of good levels of insulation in north, south and east walls, elimination of air-infiltration through the building envelope and robust construction. </li></ul><ul><li>Optimised use of natural lighting in the sports hall so reducing the need for high levels of artificial lighting . </li></ul><ul><li>Naturally ventilated sports hall, eliminating the need for mechanical cooling and provision of fresh air. </li></ul><ul><li>Replacement of the proposed high level, high temperature, gas fired, air blown heating system with an under-floor, low temperature heating system powered at least in part by a ground source heat pump system and a wind turbine situated in the school grounds. </li></ul><ul><li>Install a roof mounted solar hot water system to provide part of the high temperature water supply needed for the changing room facilities. </li></ul>
  24. 26. The Aim Of The Project To develop a Carbon Footprint calculation methodology suitable for use in the design stage of construction projects.
  25. 27. Barriers to developing a methodology for the construction industry <ul><li>The lack of one globally agreed definition of the term ‘carbon footprint’. </li></ul><ul><li>The lack of agreement on the units to be used in the calculation methodology - CO 2 or CO 2e ? </li></ul><ul><li>Analysis boundaries for construction projects – Cradle to Gate or Cradle to Grave? Must be clearly specified to avoid ‘double counting’ of emissions. </li></ul>
  26. 28. Barriers (continued). <ul><li>The complexity of construction projects – How can a single emission figure be produced for the construction of 100m of 2 lane road carriageway? Calculation of the footprint of a project could involve data sharing and cooperation between the client, designers, contractors and subcontractors. </li></ul><ul><li>The format and availability of data required for the methodology – in order to become an accepted part of the design process, data availability, collection and input can’t be a laborious time consuming process. </li></ul><ul><li>Current legislation and policies – any methodology must comply with and contribute towards achieving targets and benchmarks set out in legislation. </li></ul>
  27. 29. What is the best strategy to reduce our dependence on Carbon intensive energy? <ul><li>How do carbon emissions vary from different fuel types in reality? </li></ul><ul><li>How sensitive are these different types to carbon accounting? </li></ul>Comparison study of Nuclear, Coal and Wind Energy with respect to Carbon Accounting Samuel Chapman [email_address]
  28. 30. Carbon Accounting of Electricity Production . <ul><li>Material based analysis (gCO 2 /kg) </li></ul><ul><ul><li>Life cycle analysis of products - Amount of materials must be known for a given project in tonnes/kilograms </li></ul></ul><ul><ul><li>Requires inventories of all materials used in construction </li></ul></ul><ul><ul><ul><li>Mass of material x GHG embodiment per unit mass </li></ul></ul></ul><ul><ul><li>Widely used: “Inventory of Carbon & Energy” - Bath University. </li></ul></ul><ul><ul><li>Still no standard inventory. </li></ul></ul><ul><ul><li>Only valid for defined system boundary - process specific </li></ul></ul><ul><li>Cost based analysis (gCO 2 /£) </li></ul><ul><ul><li>Life cycle analysis of processes - Inventory establishment for lifetime monetary cost of plant. Emission factor found using GHG intensities - amount of GHG emitted from production of one unit worth </li></ul></ul><ul><ul><li>Input-Output analysis </li></ul></ul><ul><ul><li>Assessment of how carbon intensive an economy is </li></ul></ul><ul><ul><li>Not case specific due to input-output tables & averaged intensities </li></ul></ul><ul><ul><li>Study suggests gives fuller account of emissions during construction 1 </li></ul></ul><ul><li>Combination of the two </li></ul>1
  29. 31. Sensitivity of Electricity Production methods to carbon accounting <ul><li>Using published Life Cycle Assessments to deduce sensitivities of different production methods to quantifiable assessment. </li></ul><ul><ul><li>Sensitivity = Contribution Score x Data Rating </li></ul></ul><ul><ul><li>Where </li></ul></ul><ul><ul><li>Contribution score : The smaller the value, the lesser the contribution to total life cycle emissions </li></ul></ul><ul><ul><li>Data Rating : </li></ul></ul><ul><ul><ul><li>1 - available, published data </li></ul></ul></ul><ul><ul><ul><li>2 - generic data, assumptions and availability of choice present </li></ul></ul></ul><ul><ul><ul><li>3 - missing data, omitted data </li></ul></ul></ul>
  30. 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
  31. 33. Sensitivity vs. Total Life Cycle Emissions Nuclear Power is currently the most vulnerable to carbon accounting <ul><li>Sources: </li></ul><ul><li>AEA Technology - Environment product Declaration of electricity from Torness Nuclear Power Plant </li></ul><ul><li>Naser Odeh & Timothy Cockerill - LCA of typical coal power plant & LCA of coal plant with CCS </li></ul><ul><li>Lewis Wind Farm Proposal </li></ul><ul><li>Elsam Engineering - LCA of onshore sited wind farms </li></ul>
  32. 34. What does it all mean? <ul><li>Need to open debate of accountability of electricity production methods. </li></ul><ul><li>We need to have clear boundary definitions set that concern the entire life cycle of projects - pressure on all energy related industries to account in a standard manner </li></ul><ul><li>Reduce the number of assumptions made in assessments </li></ul><ul><li>Reduce involvement in projects with high degrees of uncertainty </li></ul><ul><li>Need a structure in place to meet legislation </li></ul><ul><li>House of Commons suggests current average of 541gCO 2 /kWh emissions factor to our electricity. This is the key figure to bring down, since it relates to every electricity-using object in Britain. Refers to our energy mix </li></ul>Need to reach a point where we can assess all aspects of electricity production and, like the car’s MOT certificate, be able to say about a project: fix or scrap , based on quantifiable assessment. I would like to invite you to open discussion on this topic.
  33. 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
  34. 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
  35. 37. Where the UK gets its Coal from – Imports ? Source: Andrew Peacock
  36. 38. Where the UK gets its Coal from Source: Andrew Peacock
  37. 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
  38. 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
  39. 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.
  40. 42. What we need is a Carbon Accounting Network for Buildings and Cities
  41. 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.

Editor's Notes

  • This is a presentation of two parts. First I want to ask why are we counting carbon? The answer is a paradox Because it’s so cheap. We know we must but if it were priced according to its importance, it would be an intrinsic part of all accounting systems so counting would be automatic. The second part looks at the state of play on carbon counting rules of the game
  • This is the iconic climate change graph. There is consensus that BAU will cause catastrophe this century
  • Here are the low hanging fruit – these are the costs of saving CO2 by energy efficiency measures in commercial buildings. Most are less than £100/tonne, most are not being implemented
  • We’ve had the headlines about household energy bills averaging £1,000/yr. This is what would happen to household energy bills in the different worlds if no actions were taken. The problem is that even in Dream world, most households might not take action. It’s only on Fuel’s Paradise that the pain is intolerable. There demand reduction would kick in with a vengeance and household energy costs could be contained. When the emergency is accepted as such surely the govt will move from marginally rewarding altruistic behaviour to seriously penalising unacceptable profligacy. DEFRA has pitched the shadow price of carbon at £25 part way between Climate Cuddles and Dream world. Stern was talking about £50 - 75
  • So let’s look again at the 3 paths. We have Choice 1 the BAU curve or climate cuddles. Very easy to let happen. Then we have Choice 3 Fuel’s Paradise. The path recommended by the scientists – very difficult socially and politically Finally Choice 2, Dream world, the relatively pain-free path urged on us by the Stern review. Do we gamble the future of civilisation on this working?
  • Each benchmark can be broken down into the energy used by lighting, fans, PCs, etc for a typical ‘iconic’ example of the building category. This help ensure the consistency between the benchmarks. And in due course, might be used to benchmark the energy systems which will help identify energy efficiency measures.
  • This is the design of the DEC.
  • In the UK we have 40% of Europe&apos;s total wind energy. But it&apos;s still largely untapped and only 0.5% of our electricity requirements are currently generated by wind power.
  • Adv of cost based analysis - last bullet point. Combination of the two can be used - process analysis could be used for material production while other processes using input-output tables.
  • Explain quickly the Total Life Emissions graph…scale reduced to show better other elec methods in relation to traditional coal. Wind - Figures taken from Lewis Wind project - larger due to peat disturbance potential of the project - suggested high figure for wind. Danish project suggests a low figure for wind Nuclear figure from torness study by AEA Technology.