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ENV-2D02 Energy Conservation

ENV-2D02 Energy Conservation. Jane Powell (JC) j.c.powell@uea.ac.uk. Building Regulations. What is energy conservation?. Supply and Demand Supply More efficient production CHP Changing demand More appropriate use Fuel switching Use less Demand management Reduce heat loss

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ENV-2D02 Energy Conservation

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  1. ENV-2D02 Energy Conservation Jane Powell (JC) j.c.powell@uea.ac.uk Building Regulations

  2. What is energy conservation? • Supply and Demand • Supply • More efficient production • CHP • Changing demand • More appropriate use • Fuel switching • Use less • Demand management • Reduce heat loss • Low energy appliances • Behavioural change

  3. Why is energy conservation important? • 2030 (EU) • Based on present trends • 90% imported oil • 80% imported gas • Climate change • Limits to fossil fuels • Security • Risks • Threat to our current way of life • Fuel poverty 3 million UK households

  4. Observed and simulated change:natural and man-made factors 1.0 0.5 0.0 -0.5 observed model simulation + Temperature change ºC + 1850 1900 1950 2000 Source: Hadley Centre

  5. UK targets • Kyoto targets • GHG 12.5% below 1990 levels 2008-2012 • 2002 14.4%; 2003 13.4%; 2004 12.6% • UK CO2 Targets • Previous target: 20% below 1990 levels by 2010 • New target: 60% below 1990 levels by 2050 • 50% 2010 target can be achieved by energy efficiency measures • Renewables • 10% electricity generated by 2010 • 3.5% 2004

  6. Reduce heat loss & behavioural change • Of who? • Occupants • Developers, planners, architects • What method? • Incentives • Subsidies • Economic instruments • Voluntary initiatives • Regulations

  7. The Energy Performance of Buildings Directive (EPBD) 2002/91/EC • 40% of final energy consumption in the EC is in the buildings sector. • Improving energy efficiency, carbon emissions from buildings could be reduced by 22%. Objectives of the Directive: • To promote the improvement of the energy performance of buildings within the EU through cost effective measures; • To promote the convergence of building standards towards those of Member States which already have ambitious levels. Measures include: • Methodology for calculating the energy performance of buildings; • Application of performance standards on new and existing buildings; • Certification schemes for all buildings; • Regular inspection and assessment of boilers/heating and cooling installations. Must be implemented by 4 Jan 2006

  8. UK ResponsePart L Building Regulations (2005) • Comes into force in England and Wales on 6 April 2006 (Scotland & Ireland to follow) • Office of the Deputy Prime Minister (ODPM) • Complies with EU legislation • Move away from energy conservation to carbon emission reduction • UK National Calculation Methodology (NCM) for energy performance of buildings

  9. Deficiencies in earlier Building Regulations • Before 1994 if double glazing was used • window area could be doubled • requirements for walls/roof/floor could be relaxed if overall loss < = standard house (type 1 trade off) • From 1995 • Could include incidental gains from appliance use/solar gains • If consumption <= standard house - regulations could be relaxed further • 1994 & 2000 regulations • If triple glazing used window area can be increased by 50% (type 2 trade off) • If higher insulations for walls used, greater window area permitted provided <= standard house. • Traditionally framed for minimum compliance rather than actively promoting energy conservation • Less so by 2000 Regs • 2005 Regs tightened further

  10. Comparison of energy consumption for a standard detached house at various ages and improvements (Heat losses in W0C-1)

  11. Effects of built form on energy consumption (Heat loss WoC-1)

  12. 1994 Regulations • Single glazing could no longer be used routinely for domestic buildings • Glazed area 22.5% of floor area • 50% greater than 1990 regs • 50% potential saving lost • Standard Assessment Procedure (SAP) rating for new buildings • 0-100 – higher the better • No target SAP but requirements relaxed if >60 • SAP 80-84 – Regs automatically satisfied • Includes energy running costs in calculation • Trade offs permitted • Does not specify ventilation rates but advise on estimating • Make allowance for solar water heating • Include hot water requirements

  13. Building Regulations 2000 • Current regulations - implemented April 2002 • Energy rating method • SAP replaced by Carbon Index method for compliance • SAP ratings still to be calculated and notified to building control bodies • Requirement of heating & hot water changed to encompass overall system performance, not just controls • Boiler seasonal efficiency, inspection & commissioning included • New requirements for efficient lighting systems & provision of information for householders • Standards of fabric insulation improved • Lower (better) standards (loft insulation) • Reductions in U values (technical limits) • Changed methods for calculating U values • Lower U values for windows • Based on sealed double-glazed units with low emissivity panes • Area of glazing increased to 25% floor area • Target U-value method retained but provisions for trade-offs improved.

  14. Compliance procedures 2000 Regulations Three methods to demonstrate compliance with Building Regulations: • Elemental approach • Target U-Value method • Carbon Index • 1. Elemental approach – meet specific conditions • Heating must be gas, oil, heat pump, CHP DH, biogas or biomass • U-values < BR2000 standards • Area window, doors, roof lights <=25% floor area • Boiler: SEDBUK efficiency >=78% gas, 80% LPG, 85% oil • [SEDBUK – Seasonal efficiency of domestic boilers in the UK. The average annual efficiency achieved in typical domestic conditions.]

  15. 2. Target U-Value method • Calculate Target U-Value • a function of areas of floor, roof, walls, windows etc • Modify target • gas & oil boilers: actual SEDBUK efficiency standard SEDBUK efficiency • electric & coal heating: divide by 1.15 • No modification for heat pumps, biomass, biogas, CHP • Modify target if area south facing windows > area north facing windows • Calculate weighted average U-value of all external surfaces • Weighted average U-value must be <= Target value

  16. 3. Carbon Index Method • Most complex method • Replaces SAP energy rating as a method of compliance • Carbon index appears to be 0-10 • Must be >= 8 to comply • Max carbon index 10 – but actually 17.7! • Reality: 8 out of 17.7 or 4.5 out of 10! • SAP procedure is followed • up to point of introducing costs of fuels • actual annual energy consumption is used to calculate the annual carbon dioxide emission • translated into a carbon index

  17. Standard Assessment Procedure (2001) • Calculate U-values • Check U-values are achieved • Calculate • gross heat requirements (Heat Loss Rate) • hot water requirements • incidental & solar gains • effective gains • effective internal temperature • corrected degree-day parameter • net space heating total energy requirement • Select heating method (pumps, appliance efficiency) • Calculate Total Energy Requirement • Estimate energy costs of total space heating, hot water & pumps • Deflate energy by Energy Cost Factor – 0.96 1994, 1.05 2001

  18. Carbon Index Calculations (2000 regulations) • Attempts to assess the true environmental performance of a building • Follow Standard Assessment Procedure to calculate Total Energy Requirement • Calculate CO2 emissions for building • Calculate Carbon Factor (CF) • CF=CO2 (TFA+45) where TFA is total floor space • Carbon Index (CI) CI=17.7-9.0 log10(CF) • Complication of scale >10 • Present regulations (2000) indicate that compliance is 11kg CO2 per m2 – carbon index of 8 • If true scale was used Zicer & Elizabeth Fry would out perform the theoretical 10 out of 10 building.

  19. SAP U-values Total Energy Requirement Energy costs Energy Deflator 1-100 1-120 (SAP 2001) CARBON Index C02 emissions Carbon Factor >=8

  20. Carbon emissions for same house designed to different standards

  21. Critique of the Standard Assessment Procedure (SAP) • Energy efficiency index – but gives a rating that is monetary based not energy based • Assumes a general heating level in house – no variation • Hot water requirements based on floor area formula not occupancy • Incidental gains based on floor area not occupancy • Standing charge ignored for electricity, included for gas. Oil doesn’t have a fixed charge (1994 & 2000) • Lower efficiency oil heating can give a higher SAP rating than more efficient gas • Energy Cost Deflator • Unnecessary complication that allows for inflation • 1994 Regs – possible SAP rating of over 110 • SAP of 100 achievable • 2000 Regs – widen scale (over 120) to keep houses at similar value • Better to have max of 100 for zero energy house

  22. Effective changes in SAP rating with specific changes (1994 regulations) Source: Monahan, J (2002) MSc Dissertation UEA; Turner, C. (2003) BSc Dissertation UEA

  23. 2006!!!

  24. Draft 2005 Building Regulations • Comes into force 6th April 2006 • Will use SAP 2005 • Technical changes • Changes in how U values are calculated • Thermal bridging – weighted average to be considered, not just design • Pressure testing of buildings for developments over a specific size • U-values windows – include frames • Information on lighting use • Estimates of overheating in summer included • Shading issues relating to solar gain must be addressed

  25. Draft 2005 Building Regulations: Compliance Greatest change is how compliance is achieved - five criteria: • Dwelling Emission Rate (DER) • Gives considerable latitude in design • Limits on design flexibility • limits trade-offs • Limit effects of solar overheating • South facing windows, ventilation • Quality of construction – evidence of actual performance • Quality of workmanship • Pressure testing of large buildings & developments • Providing information • Maintenance and operation of the building • (Home Information Pack)

  26. Dwelling Emission Rate (DER) • Is equal to CO2 emissions per unit floor area for space and water heating and lighting less emissions saved by energy generation • New dwellings & extensions • Non Dwellings & large dwellings >450m2 • Building Emission Rate

  27. SAP U-values Total Energy Requirement Energy costs Energy Deflator 1-100 1-120 (SAP 2001) CARBON Index C02 emissions Carbon Factor >=8 Target Emission Rate C02/m2 Dwelling Emission Rate DER<TER

  28. UK National Calculation Methodology (NCM) for energy performance of buildings • Compliance with the 2006 amendments to Part L of the Building Regulations in England and Wales (similar for Scotland and N. Ireland) • Dwellings: NCM new version of the existing Standard Assessment Procedure (SAP) • Non domestic buildings: Simplified Building Energy Model (SBEM) • prototype www.ncm.bre.co.uk • user interface called iSBEM. • Purpose: to produce consistent and reliable evaluations of energy use in non-domestic buildings (and some domestic buildings) • for building performance certification purposes (eventually) • (Home information packs - 1 June 2007)

  29. SAP 2005 Regulations • Basic methods similar to previous regulations • Calculations more complicated • Takes into consideration • window frames • solar gain • energy for lighting • effect of thermal bridges • energy generated by micro CHP, photovoltaics, etc • Problems with monetary values remain • Recalibration of scale • A house with a previous SAP rating will be reduced • SAP 2005 rating is related to the energy cost factor (ECF) by: • If ECF>=3.5, SAP 2005 = 111-110*log10(ECF)(1) • If ECF<3.5, SAP 2005 = 110-13.96*ECF (2) • SAP rating scale (1-100) - SAP100 is achieved at zero ECF • Can be >100 if house is net exporter of energy

  30. Summary Table of U-values for different Building Regulations

  31. English housing tenure by SAP rating, 2001ODPM (2003)

  32. Effects of Building Regulations Part L • 2002, 2005 & 2008 amendments should increase efficiency of new build and extensions by 25% • …but will it?

  33. What are the barriers to using building regulations to reduce energy use and carbon emissions ?

  34. UK residential sector accounts for 30% total UK energy demand • 1990 – 2003 • Total UK energy demand increased 7.3% • Residential energy increased 17.5% • Since 1970 • Energy use per household changed little • Overall energy use for residential sector increased by 32% • At household level • Reduction in heat loss – energy saving • Increases in energy demand – lights & appliances

  35. Population & households • UK population • current aprox 60 million • 2050 62.5 – 72 million • Age structure • 2003 – 76.2 men, 80.6 women • 2031 – 81.0 men, 84.9 women • Total population over 65 • 2002 10.9 m, 2031 12.7 m, 2060s 17 m • Household size • 1961 3.01; 2004 2.33 • One person households: 1971 18%, 2002 29%

  36. Effects of household size on energy useFawcett et al (2000)

  37. Construction & demolition • Building regulations are for new houses & extensions • In UK very low levels of construction & demolition • 2002/3 167,000 housing starts • 1996 – 2004 nearly 160,000 dwellings demolished – 20,000/year • If we continued at this rate the average house will last 1000 years!

  38. Future of household energy supply lies in the hands of: • Central government • 400 local authorities • 25 million households • Appliance and fuel supply industries • Construction building services • Fragmented • Multiple suppliers of specialist products • Huge number of sub contractors • Costs saved by: • reducing capital costs • standard components • standard practices

  39. Whole life costs/life-cycle costs • typical costs for owning a building are in the ratio of : • 1 for construction costs • 5 for maintenance costs • 200 for building operating costs Source: Royal Academy of Engineering

  40. Life cycle cost (LCC) • LCC = Capital Cost + Present worth of Maintenance and Energy Cost  - Present worth of Salvage value • Capital cost • initial capital expense for equipment • the system design, engineering, and installation. • Maintenance: operation and maintenance costs/year • Energy cost: yearly fuel cost. • Salvage value: net value in the final year • http://wcm.nu/LCC/lcc_calculation.html

  41. Thank you

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