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Climate Change: The Hard Choices Facing us What the Engineer can do to help

Norwich Engineering Society 5 th November 2007. C Red. Carbon Reduction. Climate Change: The Hard Choices Facing us What the Engineer can do to help. Recipient of James Watt Medal 5 th October 2007. Keith Tovey ( 杜伟贤) MA, PhD, CEng, MICE, CEnv Energy Science Director

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Climate Change: The Hard Choices Facing us What the Engineer can do to help

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  1. Norwich Engineering Society 5th November 2007 CRed Carbon Reduction Climate Change: The Hard Choices Facing us What the Engineer can do to help Recipient of James Watt Medal 5th October 2007 Keith Tovey (杜伟贤) MA, PhD, CEng, MICE, CEnv Energy Science Director HSBC Director of Low Carbon Innovation CRed

  2. ZICER Building Heating Energy consumption as new in 2003 was reduced by further 57% by careful record keeping, management techniques and an adaptive approach to control. Incorporates 34 kW of Solar Panels on top floor Low Energy Building of the Year Award 2005 awarded by the Carbon Trust.

  3. Changes in Temperature

  4. 2003 1979 Climate ChangeArctic meltdown 1979 - 2003 • Summer ice coverage of Arctic Polar Region • Nasa satellite imagery • 20% reduction in 24 years Source: Nasahttp://www.nasa.gov/centers/goddard/news/topstory/2003/1023esuice.html

  5. Options for Electricity Generation in 2020 - Non-Renewable Methods Nuclear New Build assumes one new station is completed each year after 2018.

  6. Options for Electricity Generation in 2020 - Renewable

  7. Options for Electricity Generation in 2020 - Renewable Area required to supply 5% of UK electricity needs ~ 300 sq km But energy needed to make PV takes up to 8 years to pay back in UK.

  8. Options for Electricity Generation in 2020 - Renewable • Transport Fuels: • Biodiesel? • Bioethanol? • Compressed gas from • methane from waste. But Land Area required is very large - the area of Norfolk and Suffolk would be needed to generated just over 5% of UK electricity needs.

  9. Options for Electricity Generation in 2020 - Renewable

  10. Options for Electricity Generation in 2020 - Renewable

  11. Options for Electricity Generation in 2020 - Renewable Output 78 000 GWh per annum Sufficient for 13500 house in Orkney Save 40000 tonnes of CO2

  12. Options for Electricity Generation in 2020 - Renewable

  13. Solar Energy - The BroadSol Project Solar Collectors installed 27th January 2004 Annual Solar Gain 910 kWh

  14. Performance of a Solar Thermal System Data collect 9th December 2006 – 30th October 2007

  15. 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!

  16. Our Choices: They are difficult: Energy Security There is a looming capacity shortfall Even with a full deployment of renewables. A 10% reduction in demand per house will see a rise of 7% in total demand - Increased population decreased household size • Opted Out Coal: Stations can only run for 20 000 hours more and must close by 2015 • New Nuclear assumes completing 1 new nuclear station each year beyond 2018 • New Coal assumes completing 1 new coal station each year beyond 2018

  17. Our Choices: They are difficult • Do we want to exploit available renewables i.e onshore/offshore wind and biomass. Photovoltaics, tidal, wave are not options for next 20 years. • If our answer is NO • Do we want to see a renewal of nuclear power • Are we happy with this and the other attendant risks? • If our answer is NO • Do we want to return to using coal? • then carbon dioxide emissions will rise significantly • unless we can develop carbon sequestration and apply it to ALL our • COAL fired power stations within 10 years - unlikely. If our answer to coal is NO Do we want to leave things are they are and see continued exploitation of gas for both heating and electricity generation? >>>>>>

  18. Our Choices: They are difficult • If our answer is YES • By 2020 • we will be dependent on around 70% of our heating and electricity from GAS • imported from countries like Russia, Iran, Iraq, Libya, Algeria • Are we happy with this prospect? >>>>>> • If not: • We need even more substantial cuts in energy use. • Or are we prepared to sacrifice our future to effects of Global Warming by using coal? - the North Norfolk Coal Field? – • Aylsham Colliery, North Walsham Pit? Do we wish to reconsider our stance on renewables? Inaction or delays in decision making will lead us down the GAS option route and all the attendantSecurity issues that raises.

  19. On average each person in UK causes the emission of 9 tonnes of CO2 each year. How many people know what 9 tonnes of CO2 looks like? 5 hot air balloons per person per year. Around 4 million over Norfolk. In the developing world, the average is under 1 balloon per person Is this Fair? "Nobody made a greater mistake than he who did nothing because he thought he could do only a little." Edmund Burke (1727 – 1797)

  20. Raising Awareness At Gao’an No 1 Primary School in Xuhui District, Shanghai • A tumble dryer uses 4 times as much energy as a washing machine. Using it 5 times a week will cost over £100 a year just for this appliance alone and emit over half a tonne of CO2. • 10 gms of carbon dioxide has an equivalent volume of 1 party balloon. • A Mobile Phone charger: up to 20 kWh per year • ~ 1000 balloons each year. 10 kg CO2 • Standby on electrical appliances • 60+ kWh a year - 4000 balloons. • Filling up with petrol (~£38 for a full tank – 40 litres) • --------- 90 kg of CO2 (5% of one hot air balloon) How far does one have to drive in a small family car (e.g. 1400 cc Toyota Corolla) to emit as much carbon dioxide as heating an old persons room for1 hour? 1.6 miles

  21. Involve the local Community • The residents on the island of Burray (Orkney) campaigned for a wind turbine. • On average they are more than self-sufficient in electricity needs and indeed are a net exporter of electricity. • Many of the Islanders bought shares in the project and are now reaping the reward. • Orkney is hoping to be a zero net emitter of carbon dioxide by 2015. • Even better things are happening on the Island of Westray.

  22. Involve the local Community Even better things are happening on the Island of Westray. The Parish Kirk, and Community Centre are heated by heat Pumps partly powered by Wind Turbines Waste cooking oil from other islands is processed into biodiesel for farm and other vehicles. Ethanol used in process is obtained from fermentation of harvested sea weed

  23. The ZICER Building - Description • Four storeys high and a basement • Total floor area of 2860 sq.m • Two construction types • Main part of the building • High in thermal mass • Air tight • High insulation standards • Triple glazing with low emissivity

  24. Operation of the Main Building Regenerative heat exchanger Space for future chilling Incoming air into the AHU Filter Heater The air passes through hollow cores in the ceiling slabs The return air passes through the heat exchanger Out of the building • Mechanically ventilated that utilizes hollow core ceiling slabs as supply air ducts to the space Recovers 87% of Ventilation Heat Requirement. Return stale air is extracted from each floor Air enters the internal occupied space

  25. The concrete slabs absorb and store heat Heat is transferred to the air before entering the room Importance of the Hollow Core Ceiling Slabs The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures Winter Day Winter day

  26. When the internal air temperature drops, heat stored in the concrete is emitted back into the room Importance of the Hollow Core Ceiling Slabs The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures Winter Night Winter night

  27. Cold air Cools the slabs to act as a cool store the following day Cold air Importance of the Hollow Core Ceiling Slabs The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures Summer Night – night ventilation/free cooling Draws out the heat accumulated during the day Summer night

  28. Warm air Warm air Importance of the Hollow Core Ceiling Slabs The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures Summer Day Pre-cools the air before entering the occupied space Summer day The concrete absorbs and stores the heat – like a radiator in reverse

  29. Thermal Properties of Buildings • Heating energy requirement is strongly dependant on External Temperature. • Thermal Lag in Heavy Weight Buildings means consumption requirements lags external temperature. • Correlation with temperature suggests a thermal lag of ~ 8 hours. • Potential for predictive controls based on weather forecasts Data collected 10th December 2006 – April 29th 2007

  30. Good Management has reduced Energy Requirements 800 350 The space heating consumption has reduced by 57% But this has only been possible because of realtively heavy weight construction Acknowledgement: Charlotte Turner

  31. Life Cycle Energy Requirements of ZICER as built compared to other heating/cooling strategies Naturally Ventilated 221508GJ Air Conditioned 384967GJ As Built 209441GJ Materials Production Materials Transport On site construction energy Workforce Transport Intrinsic Heating / Cooling energy Functional Energy Refurbishment Energy Demolition Energy 28% 54% 34% 51% 29% 61%

  32. Comparison of Life Cycle Energy Requirements of ZICER Comparisons assume identical size, shape and orientation Compared to the Air-conditioned office, ZICER recovers extra energy required in construction in under 1 year.

  33. ZICER Building • Top floor is an exhibition area – also to promote PV • Windows are semi transparent • Mono-crystalline PV on roof ~ 27 kW in 10 arrays • Poly- crystalline on façade ~ 6/7 kW in 3 arrays Photo shows only part of top Floor

  34. Arrangement of Cells on Facade Individual cells are connected horizontally If individual cells are connected vertically, only those cells actually in shadow are affected. As shadow covers one column all cells are inactive

  35. Use of PV generated energy Peak output is 34 kW Sometimes electricity is exported Inverters are only 91% efficient Most use is for computers DC power packs are inefficient typically less than 60% efficient Need an integrated approach

  36. 3% Radiation Losses 11% Flue Losses GAS Exhaust Heat Exchanger Engine Generator 36% Electricity 50% Heat Conversion efficiency improvements – Building Scale CHP Localised generation makes use of waste heat. Reduces conversion losses significantly 36%efficient 61% Flue Losses 86%efficient Engine heat Exchanger

  37. Conversion efficiency improvements Before installation After installation This represents a 33% saving in carbon dioxide

  38. Conversion efficiency improvements Load Factor of CHP Plant at UEA Demand for Heat is low in summer: plant cannot be used effectively More electricity could be generated in summer

  39. Heat from external source High Temperature High Pressure Heat rejected Desorber Compressor Heat Exchanger Condenser Throttle Valve W ~ 0 Evaporator Absorber Low Temperature Low Pressure Heat extracted for cooling Conversion efficiency improvements Normal Chilling Adsorption Chilling 19

  40. A 1 MW Adsorption chiller • Adsorption Heat pump uses Waste Heat from CHP • Will provide most of chilling requirements in summer • Will reduce electricity demand in summer • Will increase electricity generated locally • Save 500 – 700 tonnes Carbon Dioxide annually

  41. Target Day Results of the “Big Switch-Off” With a concerted effort savings of 25% or more are possible How can these be translated into long term savings?

  42. 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

  43. Conclusions • Hard Choices face us in the next 20 years • Effective adaptive energy management can reduce heating energy requirements in a low energy building by 50% or more. • Heavy weight buildings can be used to effectively control energy consumption • Photovoltaic cells need to take account of intended use of electricity use in building to get the optimum value. • Building scale CHP can reduce carbon emissions significantly • Adsorption chilling should be included to ensure optimum utilisation of CHP plant, to reduce electricity demand, and allow increased generation of electricity locally. • Promoting Awareness can result in up to 25% savings • The Future for UEA: Biomass CHP? Wind Turbines? "If you do not change direction, you may end up where you are heading." LaoTzu (604-531 BC) Chinese Artist and Taoist philosopher

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