Local Climate Change and Urban Mitigation Techniques to Counterbalance it. Mat Santamouris

Transcription

1 1 Local Climate Change and Urban Mitigation Techniques to Counterbalance it Mat Santamouris

2 THE EVIDENCE OF GLOBAL AND LOCAL CLIMATE CHANGE 2 Ambient Temperatures have increased The frequency of heat waves has increased Duration of Hot Spells has increased The Intensity of Heat Island is increasing continuously. Atmospheric Research Long term changes in diurnal temperature range in Cyprus Colin Price, Silas Michaelides, Stylianos Pashiardis, Pinhas Alpert Source : M. Santamouris D. Kolokotsa Climatic Change and Urban Mitigation Techniques, Published by Francis and Taylor, 2015

3 Overheating Trend (Degrees per Decade) GLOBAL OVERHEATING TREND Overheating Trend (Degrees per Decade) Average Trend per Decade after Source : M. Santamouris On The Energy Impact of Urban Heat Island and Global Warming on Buildings, Energy and Buildings, 82, 2014

4 EVIDENCE OF LOCAL CLIMATE CHANGE 4 Source : : National Observatory of Athens

5 EVIDENCE OF LOCAL CLIMATE CHANGE 5 Source : : National Observatory of Athens

6 URBAN HEAT ISLAND AND LOCAL CLIMATE CHANGE 6 Source : : National Observatory of Athens

7 URBAN HEAT ISLAND IN ASIA AND AUSTRALIA 8 Source : M. Santamouris Analyzing the heat island magnitude and characteristics in one hundred Asian and Australian cities and regions, Science of the Total Environment (2015)

8 MAGNITUDE OF HEAT ISLAND MEASURED THROUGH URBAN TRAVERSES 12 Source : M. Santamouris Analyzing the heat island magnitude and characteristics in one hundred Asian and Australian cities and regions, Science of the Total Environment (2015)

9 URBAN HEAT ISLAND AND LOCAL CLIMATE CHANGE 13 Source : : M. Santamouris : Cooling of Buildings. Past, Present and Future, Energy and Buildings, 2016

10 THE IMPACT ON PEAK POWER DEMAND 14 ` The peak electricity demand of electricity per degree of increase of the ambient temperature varies from 0,4 % for Tokyo to 4,6 % for Thailand. In average, there is a penalty on peak electricity demand of about 20 W per person and degree of temperature increase Source : M. Santamouris et al C. On The Impact of Urban Heat Island and Global Warming on the Power Demand and Electricity Consumption of Buildings A Review, Energy and Buildings, 2015

11 THE IMPACT ON ENERGY CONSUMPTION IN CITIES 15 Source : M. Santamouris On The Energy Impact of Urban Heat Island and Global Warming on Buildings, Energy and Buildings, 82, 2014

12 THE IMPACT ON ENERGY 16 Source : M. Santamouris On The Energy Impact of Urban Heat Island and Global Warming on Buildings, Energy and Buildings, 82, 2014

13 THE IMPACT ON ENERGY 17 Source : M. Santamouris On The Energy Impact of Urban Heat Island and Global Warming on Buildings, Energy and Buildings, 82, 2014

14 TEMPORAL INCREASE OF THE ENERGY CONSUMPTION 18 Source : M. Santamouris On The Energy Impact of Urban Heat Island and Global Warming on Buildings, Energy and Buildings, 82, 2014

15 Residential Consumption for Cooling (kwh) The Future Consumption of Air Conditioning The 2050 Cooling Consumption of Residential Buildings 2.50E+13 High Development Scenario Average Development Scenario Low Development Scenario 2.00E % 1.50E E E % 1620 % 750 % 1330 % 320 % 0.00E

16 THE IMPACT ON INDOOR COMFORT 23 Source : A. Sakka, M. Santamouris et al On the thermal performance of low income housing during heat waves, Energy and Buildings, Volume 49, June 2012, Pages 69-77

17 Log Mortality Rate THE IMPACT ON HEALTH 24 21,7 23, , Apparent Temperature Athens 32,7 C 4-5,0 0, Milan 31,8 C Rome 30,3 C Source : Baccini et al, 2011 Turin 27 C Valencia 28,2 C Barcelona 22,4 C London 23,9 C Helsinki 23,6 C Praha 22,0 C Stockholm 21,7 C

18 CLIMATE CHANGE MITIGATION TECHNOLOGIES 25 To face the problem both mitigation and adaptation plans have to be undertaken. Proper mitigation techniques should include any anthropogenic intervention to reduce the sources and enhance the sinks of temperature anomaly

19 THE IMPACT ON ENERGY 26 Techniques to Improve the Urban Microclimate and Heat Island Mitigation strategies concentrate on : - the increased use of green areas, -the use of appropriate materials, in particular of white and colored high reflective coatings, - decrease of anthropogenic heat - use of cool sinks for heat dissipation, - appropriate layout of urban canopies involving the use of solar control, techniques to enhance air flow, etc. Source : M. Santamouris D. Kolokotsa Climatic Change and Urban Mitigation Techniques, Published by Francis and Taylor, 2015

20 DEVELOPMENT OF ADVANCED MATERIALS FOR MITIGATION 27 Phase 1 Phase 2 Phase 3 Phase 4 Development of White High Reflective Coatings Development of infrared Reflective Colored Coatings Development of PCM doped Highly Reflective Materials Development of Highly Reflective Asphaltic Materials Phase 5 Phase 6 Phase 7 Phase 8 Development of Thermochromic Materials Research on Advanced Reflective Membranes Research on Retroreflective Materials Research on Thermoelectric / PV assisted Materials Source : M. Santamouris A. Synnefa T. Karlessi Using advanced cool materials in the urban built environment to mitigate heat islands and improve thermal comfort conditions Solar Energy 85 (2011)

21 PHASE 1 : DEVELOPMENT OF HIGHLY REFLECTIVE WHITE MATERIALS 29 During the day period, the maximum temperature difference between the white tiles was around 5 C as a function of their reflectivity. The difference between the white and aluminum tiles was up to 11 C. ` During the night period maximum temperature difference between the white paints was around 2 C, while the maximum temperature difference between the white and the aluminum base paints was around to 5 C. In this case, the role of the emissivity is dominant. Source : A. Synnefa and M. Santamouris A study of the thermal performance of reflective coatings for the urban environment, Solar Energy, Volume 80, Issue 8, August 2006, p.p Best and Oustanding Paper Awatd published in Solar Energy during

22 PHASE 2 : DEVELOPMENT OF INFRARED REFLECTIVE COLORED COATINGS 30 Cool colored coating presenting a much higher reflectivity in the infrared as well as a high emissivity have been designed, developed and tested. ` The coatings have been tested extensively as it concerns their durability, age problems and optical degradation The thermal performance of the coatings against conventional materials of similar color is extensively tested Source : A. Synnefa M. Santamouris et al On the development, optical properties and thermal performance of cool colored coatings for the urban environment, Solar Energy 81 (2007)

23 PHASE 2 : DEVELOPMENT OF INFRARED REFLECTIVE COLORED COATINGS 31 ` During the day, all the cool colored coatings had surface temperatures lower than the colored-matched standard coatings. The best performing cool coatings were black, chocolate brown, blue and anthracite, which maintained differences in mean daily surface temperature from their respective standard color-matched coatings by 5.2, 4.7, 4.7 and 2.8 C, during the month of August. The highest temperature difference was observed between cool and standard black and was equal to 10.2 C, corresponding to a difference in their solar reflectance of 22 %. The lowest temperature difference was observed between cool and standard green and was equal to 1.6 C (for August) corresponding to a difference in their solar reflectance of 7 %. Source : A. Synnefa M. Santamouris et al On the development, optical properties and thermal performance of cool colored coatings for the urban environment, Solar Energy 81 (2007)

24 0.00 to to to to to to to to to to to to to to to to to to 0.80 PHASE 2 : DEVELOPMENT OF INFRARED REFLECTIVE COLORED COATINGS albedo (x 0.67 km) The base case albedo scenario (building structures albedo a bs =0.18). 15 ` The moderate increase (x 0.67 in km) albedo scenario. The albedo of building structures (rooftops) is set to 0.63 The high increase in albedo scenario. The albedo of building structures (rooftops) is set to 0.85 The impact of albedo changes on temperature is quite significant. The spatial distribution of temperature change correlates to the level of surface modifications in the modifiable areas. The simulations suggest that the urban areas are generally cooler than in the base case. For the moderate increase in albedo case, the temperature depression at 12p.m. varies between 0.5 and 1.5 C. If the albedo is further increased then the temperature difference from the base case varies between 1-2 C, with individual depressions as high as 2.2 C. Source : A. Synnefa, A. Dandou, M. Santamouris, M. Tombrou, N. Soulakellis : Large Scale Albedo Changes using cool materials to Mitigate Heat Island in Athens. J. Applied Met, 2008

25 PHASE 3 : DEVELOPMENT OF PCM DOPED HIGHLY REFLECTIVE COATINGS 33 ` To further decrease the surface temperature of highly reflective colored coating phase change microcaplules containing parafins, (phase change T = 18 C), have been incorporated in the cool coatings. Microcapsules have a diameter of μm and are protected externally by a polymeric material. The optical and thermal performance of the materials have been tested extensively Source : Karlessi, M. Santamouris, et al Development and testing of PCM doped cool colored coatings to mitigate urban heat island and cool buildings. Building and Environment, 46, 3, 2011, Pages

26 Temperature Difference ΔΤ(C) PHASE 3 : DEVELOPMENT OF PCM DOPED HIGHLY REFLECTIVE COATINGS 34 ΔΤ(cool-PCM)blue ΔΤ(cool-PCM)black ΔΤ(common-cool)black :00 4:48 9:36 14:24 19:12 0:00-2 Time ` The surface temperature of the black cool material with PCM microcapsules was almost 3,8 C lower than the temperature of the cool black and 13,3 C lower than the common black Also, the surface temperature of blue cool material with PCM microcapsules was almost 1,8 C lower than the temperature of the cool blue Source : Karlessi, M. Santamouris, et al Development and testing of PCM doped cool colored coatings to mitigate urban heat island and cool buildings. Building and Environment, 46, 3, 2011, Pages

27 PHASE 4 : DEVELOPMENT OF HIGHLY REFLECTIVE ASPHALTIC MATERIALS 35 ` Cool Asphaltic materials have been developed and tested The materials can replace conventional asphaltic materials and are available at different colors. They present a much higher reflectivity and also a lower surface temperature compared to conventional asphalt materials. Source : A. Synnefa M. Santamouris et al On the Optical and Thermal Performance of Cool Colored Thin Layer Asphalt Used to Improve Urban Microclimate and Reduce the Energy Consumption of Buildings, Building and Environment, 46, 1, 2011, Pages 38-44

28 Solar Reflectivity PHASE 4 : DEVELOPMENT OF HIGHLY REFLECTIVE ASPHALTIC MATERIALS ` Source : A. Synnefa M. Santamouris et al Material On the Optical and Thermal Performance of Cool Colored Thin Layer Asphalt Used to Improve Urban Microclimate and Reduce the Energy Consumption of Buildings, Building and Environment, 46, 1, 2011, Pages 38-44

29 PHASE 4 : DEVELOPMENT OF HIGHLY REFLECTIVE ASPHALTIC MATERIALS 37 ` Source : A. Synnefa M. Santamouris et al On the Optical and Thermal Performance of Cool Colored Thin Layer Asphalt Used to Improve Urban Microclimate and Reduce the Energy Consumption of Buildings, Building and Environment, 46, 1, 2011, Pages 38-44

30 PHASE 4 : DEVELOPMENT OF THERMOCHROMIC MATERIALS 38 thermochro mic thermochro mic thermochr omic thermochr omic cool common cool common Thermochromic coatings change color as a function of the ambient temperature. For low outdoor temperatures, winter, the coatings may be dark presenting a high absorptivity. For higher ambient temperatures, summer, the coating becomes white presenting a high reflectivity. Thus, when applied on roofs or walls it may present the best performance all year round. Source : T. Karlessi, M. Santamouris, K. Apostolakis, A.Synnefa I. Livada : Development and Testing of Thermochromic coatings for Buildings and Urban Structures, Solar Energy, 2008

31 PHASE 4 : DEVELOPMENT OF THERMOCHROMIC MATERIALS C Common Black temperature (C) Cool Thermochromic 54.8 C --- > 4.9 K C --- > 20.9 K thermochromic cool :00 2:24 4:48 7:12 9:36 12:00 14:24 16:48 19:12 21:36 0:00 time common AR 01 Source : T. Karlessi, M. Santamouris, K. Apostolakis, A.Synnefa I. Livada : Development and Testing of Thermochromic coatings for Buildings and Urban Structures, Solar Energy, 2008

32 Temperature ( C) PHASE 7 : RESEARCH ON THERMOELECTRIC PV ASSISTED MATERIALS pv pavement soil asphalt :07 10:19 11:31 12:43 13:55 15:07 Time (min) Source : Efthymiou, M. Santamouris, D. Kolokotsa, A. Koras : Development and Testing of Photovoltaic Pavement for Heat Island Mitigation, Solar Energy, 2016

33 Average Temperature Decrease ( K ) RESULTS OF REAL SCALE APPLICATIONS , Increase of the Albedo 0 0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4 Source : M. Santamouris : Cooling the Cities A Review of Reflective and Green Roof Mitigation Technologies to Fight Heat Island and Improve Comfort in Urban Environments, Solar Energy, 103 (2014) , 2014

34 Peak Temperature Decrease ( K ) RESULTS OF REAL SCALE APPLICATIONS 54 4,0 3,5 3,0 2,5 2,0 1,5 1, ,5 Increase of the Albedo 0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4 Source : M. Santamouris : Cooling the Cities A Review of Reflective and Green Roof Mitigation Technologies to Fight Heat Island and Improve Comfort in Urban Environments, Solar Energy, 103 (2014) , 2014

35 MITIGATING THE LOCAL CLIMATE CHANGE 55 Analysis of the results of 220 large scale mitigation projects around the world, shows that there is a very high mitigation potential and it is possible to decrease the peak ambient temperature up to 5 K. New advanced systems present a much higher potential for temperature drop Source : M. Santamouris, L. Ding, F.Fiorito, P. Oldfield,P. Osmond, R. Paolini, D. Prasad, A.Synnefa : Solar Energy, 2016

36 RESULTS OF REAL SCALE APPLICATIONS IN OUTDOOR SPACES 58 TECHNIQUES TO MITIGATE HEAT ISLANDS THE FLISVOS COOL PARK Before After Use of the Developed Advanced Materials Decrease of the Peak Summer Temperature by 1,5 K. The project is under continuous monitoring for the last 4 years. Source : Santamouris et al : Using Cool Paving Materials to Improve Microclimate of Urban Areas Design Realisation and Results of the Flisvos Project. Building and Environment, 53, 2012,

37 RESULTS OF REAL SCALE APPLICATIONS IN OUTDOOR SPACES 59 CENTRAL ZONE TIRANA ALBANIA before after Use of the Developed Advanced Materials Use of earth to air Heat Exchangers for Cooling of Open Spaces Decrease of the Peak Summer Temperature up to 1,8 K. Spectacular improvement of thermal comfort Source : N. Fintikakis, M. Santamouris et al : Bioclimatic design of open public spaces in the historic centre of Tirana, Albania, Sustainable Cities and Society, Volume 1, Issue 1, February 2011, Pages 54-62

38 RESULTS OF REAL SCALE APPLICATIONS IN BUILDINGS SOUTH EUROPE 60 SCHOOL IN ATHENS Before Before After After Synnefa, M. Saliari, M. Santamouris : Experimental and numerical assessment of the impact of increased roof reflectance on a school building in Athens Original Research Article Energy and Buildings, 55, 2012,

39 RESULTS OF REAL SCALE APPLICATIONS IN BUILDINGS NORTH EUROPE 61 DAIKIN S FACTORY HOLLAND Before After Monitoring shows that before the application the indoor temperatures vary from 22.3 C to 31.7 C After FC coating application the indoor temperature varies from 19.4 C to 22.1 C. Source : E Mastrapostoli; T.Karlessi; A.Pantazaras; K.Gobakis; D. Kolokotsa; M. Santamouris : On the cooling potential of cool roofs in cold climates: Use of cool fluorocarbon coatings to enhance the optical properties and the energy performance of industrial buildings, Energy and Buildings, 69, 2014,

40 SOME CONCLUSIONS Local Climate Change and Urban heat island represents a major local climatic phenomenon, increasing considerably the temperature of urban areas. 2. This has important energy, environmental and social consequences while it deteriorates the quality of life of the citizens. 3. Existing knowledge of urban heat island is quite rich, but is overshadowed by various inconsistencies as related to the performed experimental and theoretical analysis. 4. There is a need for an objective experimental and communication protocol to be followed in future UHI studies. 5. Complete and accurate knowledge of the magnitude and the characteristics of heat island is a prerequisite for a proper and complete planning of urban mitigation and adaptation technologies.

41 SOME CONCLUSIONS Research on proper mitigation technologies has permitted to develop advanced and high quality systems and techniques that can amortise the impact of higher urban temperatures 7. Advanced materials for outdoor spaces and buildings are developed allowing to alter the thermal balance of cities, decrease the energy consumption and improve indoor and outdoor environmental quality in the built environment 8. Actual research efforts on the existing material technologies, mainly aim to improve the thermal and optical characteristics of the components, decelerate ageing effects and improve self cleaning properties. 9. Research on a future generation of building materials for mitigation purposes focusses on the use of advanced nanotechnological solutions to improve the performance of thermoelectric materials, on new materials presenting advanced chromic optical properties and on the development of piezoelectric components.

42 SOME CONCLUSIONS Research on climatic mitigation technologies should not be seen in an isolated way. It should be part of a global research aiming to face the global challenges in the urban environment and in particular the economic turmoil, the climatic change, the increased urbanisation and the urban sprawl, the increasing age of the population and the problem of poverty 11. Research on Climatic Mitigation technologies should explore interrelationships and links with advanced ICT technologies like Smart City Information Networks, Intelligent Urban Management, and also with Efficient Green Supply Networks, Zero Energy Settlements, Alternative Labor and Education Technologies, etc., in order to uncover new information about how our cities work and develop and provide integrated urban solutions that will improve the quality of citizen life by providing direct and personal services.

43 SOME CONCLUSIONS Climatic Change Research should explore all possible synergies and tradeoffs with advanced ICT technologies to become smarter and have access to the exploding amount of urban data. Digital data is expected to double every two years from now until How researchers and technology providers leverage and share this data will be a competitive differentiator. 12a. Components developed for climatic mitigation purposes should be enough intelligent to participate in the world of the Internet of Things. Today, less than 1% of things that could be connected are connected to the Internet or intelligent systems. It is expected that by 2020, there will be 212 billion "things" in the world and that by 2017, 3.5 billion people will connect to the Internet, 64% of them via mobile devices. This will generate massive amounts of data, an estimated 40 trillion gigabytes, that will have a significant impact on daily life; it will enable more efficient and better adapted climatic mitigation components an a faster response to the citizens needs.