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Responding to the Challenge

N.K. Tovey ( 杜伟贤 ) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических наук Energy Science Director C Red Project HSBC Director of Low Carbon Innovation. Code for Sustainable Homes May 1st 2008. Where we are now?. Responding to the Challenge. Recipient of James Watt Gold Medal. 1.

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Responding to the Challenge

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  1. N.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических наук Energy Science Director CRedProject HSBC Director of Low Carbon Innovation Code for Sustainable Homes May 1st 2008 Where we are now? Responding to the Challenge Recipient of James Watt Gold Medal 1 1

  2. Where we are now? • Introduction to Current Energy Issues • The twin Challenges facing us • Climate Change • Energy Security • Review of historic trends in Building Regulations and associated energy use in domestic buildings. • In Part 2: The opportunities facing us

  3. Issue of Fuel Choice • Carbon factors for each unit of fuel consumed at point of use. • The following include the transmission/ distribution losses • e.g. electricity 8.5% • energy generated locally is effectively worth more than nationally supplied energy • Gas ~ 0.19 kg/kWh • Oil ~ 0.277 kg/kWh • Coal ~ 0.33 kg/kWh • Electricity varies depending on mix of power stations. Was over 0.65 kg/kWh in 1990 but fell to 0.46 kg/kWh in 1999, but as since risen with closing of nuclear and less gas being burnt. Currently ~ 0.52 For identical situation oil boiler will cause emission of around 40% more CO2 than for gas

  4. The Hard Choices Facing Us • Climate Change Issues Carbon emissions in electricity generation will increase in next 5 years even if demand is held constant - Each unit generated by coal ~ 1000 g / kWh gas ~ 400 g/ kWh nuclear ~ 10 – 20 g/kWh • Reducing demand for electricity in homes is important • Need to reduce carbon emissions by 60% by 2050 Emissions from electricity generation will rise in short term even if we order new nuclear. Deployment of renewables is barely keeping pace with increased demand yet alone replacement of nuclear

  5. The Hard Choices Facing Us Energy Security Issues • Since 2004 UK has been importer of gas • 70% of coal is now imported • UK is no longer self sufficient in Energy • Importance of Energy Conservation not merely energy efficiency, but overall reduction in energy use • Still have major coal resources, but only viable with Carbon Capture and Sequestration because of high carbon factor • Prospects of CCS? • Hydrogen/Fuel Cells? • Only really viable when electricity generation has been decarbonised • CCS routinely available • Increase in Renewable/Nuclear Generation • CCS Unlikely except for demonstration schemes before 2020 - 2025

  6. A Pathway to a Low Carbon Future 未来的低碳之路 1. 不要浪费能源 Awareness: Information Packs 2. 使用效率高的设备 Technical Solutions to conserve energy Low energy lighting/better insulation etc 3. 使用可再生能源 Renewable Energy 4. 抵消碳排放 Offsetting

  7. Energy Consumption and CO2 Emissions in Domestic Sector Energy Consumption Carbon Dioxide Emissions Carbon Intensity has improved by 8.6% - but absolute emissions are important

  8. Energy Consumption: Comparison of Sectors The Domestic Sector is a critical area to tackle climate change

  9. Responding to the Challenge: Technical Solutions The Heat Pump Compressor Heat supplied to house High Temperature High Pressure Condenser Throttle Valve A heat pump delivers 3, 4, or even 5 times as much heat as electricity put in. Working with thermodynamics not against it. Evaporator Low Temperature Low Pressure Heat extracted from outside

  10. Issue of Fuel Choice Example: Heat house with condensing gas boiler ~ 90% efficient For each unit (kWh) of heat provided. • 1/0.9 = 1.11 units of gas must be supplied • Carbon associated with this ~ 0.21 kg • Direct electric heating ~ 0.52 kg • Heat Pump with Coefficient of Performance of 4 • Carbon emission associated = 0.52/4 = 0.13 • A 38% saving over gas. • Note some people claim higher savings based on incorrect DEFRA carbon factor of 0.43 • Improved performance of heat pumps is possible with under floor heating

  11. Changes in the Heating Standards of Houses • First introduced as Part L in 1976 • Basic Statement – largely following what was then common practice e.g. cavity walls brick cavity block with no insulation: - no insulation in floor, minimal insulation in loft. • 1994: First attempt to address overall annual energy consumption, although elemental method of compliance was still permitted • 2002: Carbon Index introduced • 2006: Target Emission Rate and Dwelling Emission Rate introduced.

  12. How has the performance of a typical house changed over the years? Bungalow in South West Norwich built in mid 1950s

  13. Changing Energy Requirements of House First attempt to address overall consumption. SAP introduced. House constructed in mid 1950s Part L first introduced ~>50% reduction In all years dimensions of house remain same – just insulation standards change As houses have long replacement times, legacy of former regulations will affect ability to reduce carbon emissions in future

  14. Changing Energy Requirements of House As Existing but with oil boiler House constructed in mid 1950s Existing house – current standard: gas boiler Improvements to existing properties are limited because of in built structural issues – e.g. No floor insulation in example shown. House designed to conform the Target Emission Rate (TER) as specified in Building Regulations 2006 and SAP 2005.

  15. Changing Carbon Dioxide Emissions House constructed in mid 1950s Code 5: Zero Carbon House for Heating/Hot Water and Lighting Code 6: Zero Carbon House overall but in reality is this achievable

  16. The Behavioural Dimension • Analysis of 114 houses in Norwich using Gas Heating • Predicted consumption from SAP was within 1.9% of actual energy consumption for Space Heating/ Hot Water and Gas Cooking. • Plot shows variation from predicted for each house • Little variation with household size • Consumption varies by up to a factor of 9 for any given household size. • Education/Awareness is important. provide INFORMATION PACKS 16

  17. The Behavioural Dimension • Household size has little impact on electricity consumption. • Consumption varies by up to a factor of 9 for any given household size. • Allowing for Income still shows a range of 6 or more. • Education/Awareness is important.

  18. CO2/ year 0 - 4 tonnes 4 - 6 tonnes 6 - 8 tonnes 8 - 10 tonnes > 10 tonnes Variations in Carbon Emissions in existing houses Analysis: courtesy of Karla Alcantar

  19. The Future: Code for Sustainable Homes • Introduced over next few years to improve standards to ultimate “zero carbon house” • But objectives of a low carbon future may be jeopardised if attention is not also paid to sustainable transport associated with new dwellings Data for 1 household with 2 cars

  20. N.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических наук Energy Science Director CRedProject HSBC Director of Low Carbon Innovation Code for Sustainable Homes May 1st 2008 Responding to the Challenge Recipient of James Watt Gold Medal 20 20

  21. Responding to the Challenge: Improvements on the SAP 2005 standards as required by the different code levels can be met by: • Improved Fabric performance • Lower U-values • Technical Solutions • Solar Thermal • Solar Photo-voltaic • Heat Pumps • Biomass • Micro- CHP • Low Energy Lighting (SAP 2005 already specifies 30%) • Energy Service Companies may offer a solution for financing • Issues of Carbon Trading

  22. Responding to the Challenge: • Improved Fabric / standard appliance Performance • SAP 2005 standard reference

  23. The Future: Code for Sustainable Homes Improvements in Insulation and boiler performance Code 1 Code 2 H nearly makes code 3

  24. Responding to the Challenge: Technical Solutions Solar Thermal Energy Basic System relying solely on solar energy

  25. Responding to the Challenge: Technical Solutions Solar Thermal Energy Solar tank with combi boiler indirect solar cylinder

  26. Responding to the Challenge: Technical Solutions Solar Thermal Energy Solar Pump Normal hot water circuit Solar Circuit Dual circuit solar cylinder

  27. Responding to the Challenge: Technical Solutions Solar Thermal Energy Solar Collectors installed 27th January 2004 Annual Solar Gain 910 kWh

  28. Responding to the Challenge: Technical Solutions Solar Thermal Energy

  29. It is all very well for South East, but what about the North? House on Westray, Orkney exploiting passive solar energy from end of February House in Lerwick, Shetland Isles with Solar Panels - less than 15,000 people live north of this in UK!

  30. The Future: Code for Sustainable Homes Improvements using solar thermal energy Code 1 Code 2 Note: little extra benefit after 3 panels, but does depend on size of house

  31. Responding to the Challenge: Technical Solutions Solar PhotoVoltaic S

  32. The Future: Code for Sustainable Homes Improvements using solar Photovoltaic Code 1 Code 2 Code 3 Note: 2 panels of solar thermal have same benefit as 5 sqm of PV

  33. Responding to the Challenge: Technical Solutions The Heat Pump • Any low grade source of heat may be used • Coils buried in garden 1 – 1.5 m deep • Bore holes • Lakes/Rivers are ideal • Air can be used but is not as good • Best performance is achieved if the temperature source between outside source and inside sink is as small as possible. Under floor heating should always be considered when installing heat pumps in for new build houses – operating temperature is much lower than radiators. Attention must be paid to provision of hot water - performance degrades when heating hot water to 55 – 60oC Consider boost using off peak electricity, or occasional “Hot Days”

  34. The Future: Code for Sustainable Homes Code 3 Code 4 Improvements using Heat Pumps Code 1 Code 2 Code 3

  35. The Future: Code for Sustainable Buildings Code 1 Code 2 Code 3 Code 4 Code 4 Improvements using Biomass options Note: Biomass with solar thermal are incompatible options

  36. Ways to Respond to the Challenge: Technical Solutions Micro CHP • Micro CHP plant for homes are being trialled. • Replace the normal boiler • But there is a problem in summer as there is limited demand for heat – electrical generation will be limited. • Backup generation is still needed unless integrated with solar photovoltaic? • In community schemes explore opportunity for multiple unit provision of hot water in summer, but only single unit in winter.

  37. The Future: Code for Sustainable Homes Code 1 Code 2 Code 3 Code 4 Various Combinations

  38. Responding to the Challenge: • How can low carbon homes be provided at an affordable cost? • Energy Service Companies (ESCos) • Home costs same initial cost as traditional home • Any additional costs for providing renewable energy, better insulation/controls are financed by ESCo • Client pays ESCo for energy used at rate they would have done had the house been built to basic 2005 standards • ESCo pays utility company at actual energy cost (because energy consumption is less) • Difference in payments services ESCo investment • When extra capital cost is paid off • Client sees reduced energy bills • ESCO has made its money • Developer has not had to charge any more for property • The Environment wins

  39. The Future: Code for Sustainable Buildings: Conclusions Significant Improvements can be achieved • Better Insulation Standards • Heat Pumps • Biomass Boilers • Solar Thermal • Solar PV • But avoid incompatible options • Too large a Solar thermal Array • Biomass with solar thermal • CHP with Solar Thermal LaoTzu (604-531 BC) Chinese Artist and Taoist philosopher "If you do not change direction, you may end up where you are heading." WEBSITE Cred-uk.org/ Follow Academic Links

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