1 CRed Keith Tovey ( 杜伟贤 ) M.A., PhD, CEng, MICE, CEnv Energy Science Director: Low Carbon Innovation Centre School of Environmental Sciences, UEA Keith Tovey Park Lane Methodist Church 28th May 2006 Climate Change – The Greatest Threat to Mankind? The fifth fuel – Energy Conservation?

2 Last Week We have hard choices to make Promote all renewables Energy conservation – each of us to reduce consumption by 1.5% each and every year – i.e. by 20+% by 2020 Even then we would see gas consumption rise by over 60% and up to 70+% will have to be imported from countries like Russia and Middle East We delayed making a decision about nuclear in 1997 Now it will be very difficult to avoid a small nuclear new build Climate Change – The Greatest Threat to Mankind? The fifth fuel – Energy Conservation?

3 Historic and Future Demand for Electricity Number of households will rise by 17.5% by 2025 and consumption per household must fall by this amount just to remain static

4 Electricity Options for the Future Low Growth Scenario Capped at 420 TWh Means everyone must reduce consumption by 1.5% each year. Assume Renewable targets are met but we are currently falling well short 33% CO 2 reduction cf % increase in gas consumption cf 2002 CAN WE JUSTIFY THIS INCREASE IN GAS? Nuclear option – 62% reduction in CO 2 Mix option retains nuclear proportion at ~ 20% ~ 5 new nuclear to replace 13 existing ones Renewable assumption we achieve target 10 times as many wind turbines as present

5 Implications of some of the Scenarios In addition we would need MW of installed capacity of biomass – or sq km devoted to biomass cultivation or we would need many more wind turbines. But we are exploiting resources of developing countries such as Malaysia – should we continue to do so and increase this exploitation?

6 By 2050 we could readily have a renewable an low carbon future. However we cannot now have a non-nuclear scenario in the period 2015 – 2030, Unless –we wish to be dependent on Russia and the middle east for are heating and electricity generation for almost all our electricity and heating. Or –we wish to see a return to coal and global warming exacerbated. By 2030 significant possibilities will exist for carbon sequestration, Or –we make more drastic cuts in energy use – a 20% cut will only see us stand still But conservation measures often do not achieve the theoretical savings predicted because of “comfort taking” Climate Change – The Greatest Threat to Mankind? The fifth fuel – Energy Conservation?

7 So where does it all go? Climate Change and our insatiable appetite for energy Per Capita Consumption in Watts ~ 5 kW Transport Energy use has risen 10.5% in last decade Domestic use has risen by over 10%

8 Opportunities for Conservation –Reduce transmission losses Local generation of electricity (8.5% in case of electricity) –Make more effective use of energy during conversion. –Reduce demand Technical means Promoting Awareness Climate Change – The Greatest Threat to Mankind? The fifth fuel – Energy Conservation?

9 Local Provision of Energy Normal hot water circuit Solar Circuit Solar Pump

10 House in Lerwick, Shetland Isles - less than 15,000 people live north of this in UK! It is all very well for South East, but what about the North? Local Provision of Energy

11 Saving Energy – A Practical Guide Ways to Reduce Your Carbon Footprint Micro Wind Micro CHP Heat Pumps

12 Many residents on island of Burray (Orkney) compaigned for a wind turbine. On average they are fully self-sufficient in electricity needs and indeed are a net exporter of electricity Involve the local Community

13 8. Generation of Electricity - Conventional Diagram illustrates situation with coal, oil, or nuclear Gas Generation is more efficient - overall ~ 45% Overall efficiency ~ 35% Largest loss in Power Station

14 8. Generation of Electricity - Conventional. Pump Multi-stage Turbine Generator Boiler Condenser Simplified Diagram of a “generating set” includes boiler, turbine, generator, and condenser Superheated Steam 563 o C 160 bar Steam at ~ 0.03 bar Why do we condense the steam to water only to heat it up again?. Does this not waste energy? NO!! Thermodynamics?

15 8. Generation of Electricity - Conventional Chemical Energy Coal / Oil / Gas Electrical Energy Heat Energy Boiler Turbine Generator Mechanical Energy Electricity used in Station Power Station 100 units 38 units 90 units 3 units 90% 95% 48% 41 units

16  Why not use the heat from power station? - it is typically at 30 o C?  Too cold for space heating as radiators must be operated ~ 60+ o C  What about fish farming - tomato growing? - Yes, but this only represent about 0.005% of heat output.  Problem is that if we increase the output temperature of the heat from the power station we get less electricity.  Does this matter if overall energy supply is increased? 8. Generation of Electricity - Conventional.

17 8. Generation of Electricity - CHP Overall Efficiency - 73% Heat is rejected at ~ 90 o C for supply to heat buildings. City Wide schemes are common in Eastern Europe

18  1947 Electricity Act blinked our approach for 35 years into attempting to get as much electricity from fuel rather than as much energy.  Since Privatisation, opportunities for CHP have increased  on an individual complex basis (e.g. UEA), unlike Russia  A problem: need to always reject heat.  What happens in summer when heating is not required? 8. Generation of Electricity - Conventional.

19 9. Applications of Thermodynamics. Combined Heat and Power Engine Generator

20 Engine Generator 36% Electricity GAS 61% Flue Losses 3% Radiation Losses 36% efficient Generation of Electricity with a Gas Engine

21 Engine Generator 36% Electricity 45% Heat GAS Engine heat Exchanger Exhaust Heat Exchanger 11% Flue Losses 3% Radiation Losses 81% efficient Combined Heat and Power at UEA Localised generation can make use of waste heat. Reduces conversion losses significantly

/98electricitygasoilTotal MWh Emission factorkg/kWh Carbon dioxideTonnes ElectricityHeat 1999/ 2000 Total site CHP generation exportimportboilersCHPoiltotal MWh Emission factor kg/kWh Carbon dioxide Tonnes Performance of CHP units Before installation After installation This represents a 33% saving in carbon dioxide

23 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

24 Before and during the break Use the computers to model the carbon emissions at home and to identify the issues which are of greatest importance. The model is approximate and will not necessarily indicate total consumption, but it will identify the issues you should think about

25 The Heat Pump High Pressure High Temperature Low Pressure Cool Temperature Low Pressure Cold Temperature High Pressure Warm Temperature Evaporator Throttle Valve Compressor Condenser Heat to building Heat from outside Work In A Heat Pump or refrigerator 3 to 4 times as much energy out as energy in!! Works with thermodynamics – NOT against it

26 Condenser Evaporator Throttle Valve Heat rejected Heat extracted for cooling High Temperature High Pressure Low Temperature Low Pressure Heat from external source Absorber Desorber Heat Exchanger W ~ 0 Normal Air-conditioning 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 Compressor Adsorption Air-Conditioning

27 The Norwich Heat Pump Original Paper by John Sumner Proc. Institution of Mechanical Engineers (1947): Vol 156 p 338

28 The History of the Site The building was unique - the very first heat pump in the UK. Installed during in early 1940s during the War. Built from individual components which were not ideal. Compressor was second hand built in early 1920’s ! for Ice making. The evaporator and condenser had to be built specifically on site. Refrigerant choice was limited during War - only sulphur dioxide was possible. A COP of 3.45 was obtained - as measured over 2 years. Even in 1940s, the heat pump was shown to perform as well as, if not better than older coal fired boiler.

29 The History of the Site The Norwich Heat Pump - note the shape of the columns Evaporator Compressor Condenser

30 The Norwich Heat Pump

31 Commercial /Hotel Development Domestic Units – Refurbishment of former Electricity Board Offices Domestic Units – Rebuild/Refurbishment of existing façade on Duke Street Model of the Redevelopment Site showing relationship between Domestic and Commercial parts of Site. Location of former Heat Pump – the first in the UK The Duke Street Project

32 A concluding thought Our Wasteful Society 650 m 21 m 273 m We behave as though we call in the RAF The Heat Pump is the analogy with the crane In memory of John Sumner

33 Climate Change and the Environment The greatest threat to mankind? Our insatiable appetite for Energy Potential of Energy Resources Hard Choices Ahead The fifth fuel – Energy Conservation? Next Week Crunch Time! –What can you do in your homes or as a community?

34 1. When cooking vegetables on a stove. How much energy (as a percentage) is saved by putting a lid on the saucepan.? 2. What are the major sources of heat loss from a house? List the conservation measures which should be adopted in order of effectiveness, and also cost? What measures would you take to improve the energy efficiency of your home? 3. By time switching the heating in a house so that it is off from 11pm until 7am the next morning, a saving of one third in energy will be possible. Is this correct? What disadvantages are there from time switching ? 4. It is often argued that with a well insulated hot water tank it does not matter if the heating source is left on. In what circumstances is this statement correct, and in what circumstances is it not? 5. Fluorescent lights use as much energy when switched on as they do in running for 15 minutes [some people say 30 minutes] or is this a myth?. What evidence can you use to confirm this or otherwise. To discuss next week Remember to bring your data you have been collecting with you