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Green Technologies and White Roofs CleanTech Forum, SF March 14, 2011

This presentation discusses the benefits of green technologies and white roofs in terms of cooling buildings, reducing energy consumption, and mitigating the effects of urban heat islands. It also highlights the potential impact of energy efficiency standards on various appliances and the importance of implementing these measures to combat climate change.

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Green Technologies and White Roofs CleanTech Forum, SF March 14, 2011

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  1. Green Technologies and White RoofsCleanTech Forum, SFMarch 14, 2011 Arthur H. Rosenfeld, Former Commissioner California Energy Commission. Distinguished Scientist Emeritus Lawrence Berkeley National Lab. AHRosenfeld@LBL.gov 510 495-2227 Presentation available at www.ArtRosenfeld.org

  2. 1970, First Earth Day E/GDP = thousand Btu/$ (in $2000) ArtRosenfeld@gmail.com or PatMcAuliffe@sbcglobal.net

  3. Source: David Goldstein, NRDC, SF

  4. Comparison of 3 Gorges to Refrigerator and AC Efficiency Improvements TWh Wholesale (3 Gorges) at 3.6 c/kWh Retail (AC + Ref) at 7.2 c/kWh Value of TWh 三峡电量与电冰箱、空调能效对比 120 7.5 100 Air Conditioners 空调 If Energy Star 80 2005 Stds 6.0 Air Conditioners 空调 TWH/Year Value (billion $/year) 2000 Stds 60 4.5 If Energy Star 3.0 40 Savings calculated 10 years after standard takes effect. Calculations provided by David Fridley, LBNL 2005 Stds Refrigerators 冰箱 20 1.5 2000 Stds 0 3 Gorges 三峡 Refrigerators 冰箱 3 Gorges 三峡 标准生效后，10年节约电量

  5. Impact of Standards on Efficiency of 3 Appliances 110 = Effective Dates of 100 National Standards Effective Dates of = State Standards 90 Gas Furnaces 80 75% 70 60% Index (1972 = 100) 60 Central A/C 50 SEER = 13 40 Refrigerators 30 25% 20 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 Year Source: S. Nadel, ACEEE, in ECEEE 2003 Summer Study, www.eceee.org

  6. United States Refrigerator Use, repeated, to compare with Estimated Household Standby Use v. Time 2000 Estimated Standby 1800 Power (per house) 1600 1400 Refrigerator Use per 1978 Cal Standard Unit 1200 1987 Cal Standard Average Energy Use per Unit Sold (kWh per year) 1000 1980 Cal Standard 2007 STD. 800 1990 Federal 600 Standard 400 1993 Federal Standard 2001 Federal 200 Standard 0 1947 1949 1951 1953 1955 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009

  7. Televisions Represent Significant Energy Use The residential energy consumption due to televisions rapidly increased from 3-4% in 1990s to 8-10% in 2008. Television energy will grow up to 18% by 2023without regulations. The projected growth does not include the residential energy use by cable boxes, DVD players, internet boxes, Blue Ray, game consoles etc.

  8. Technically Feasible Standards Each point may represent several TV models *Consumers can expect to save between $ 50 - $ 250 over the life of their TV *A 50 inch plasma can consume as little as 307 kWh/yr and as much as 903 kWh/yr

  9. General Purpose Lighting – Proposed Regulations (cont.) Proposed Table K-8: Standards for State-regulated General Services Incandescent Lamps -Tier I Proposed Table K-9: Standards for State-regulated General Services Lamps -Tier II

  10. White roofs to cool your buildings, your cities, and (this is new) to cool the earth.

  11. Summer in the city summer urban heat island 17 17

  12. Bird’s eye view of urban land use • The surface of Sacramento, CAis about • 20% roofs • 30% vegetation • 40% pavement ~ 1 km2 18 18

  13. Chicago Heat Wave 1995, 739 DeathsVirtually all of the deaths occurred on the top floors of buildings with black roofs

  14. Reflective roofs stay cooler in the sun 50 40 30 20 10 0 Galvanized Steel IR-Refl. Black Black Paint White Cement Coat. Temperature Rise (°C) Green Asphalt Shingle Al Roof Coat. Red Clay Tile White Asphalt Shingle White Paint Lt. Red Paint Lt. Green Paint Optical White 0.0 0.2 0.4 0.6 0.8 1.0 Solar Absorptance 20

  15. White roofs are popular in Tucson, AZ 21 21

  16. Washington, DC (Federal) has problems 22 22

  17. Pentagon 23 23

  18. Cooling our planet

  19. European Heat Wave 2003, 30,000 Deaths France July 2010, Few Deaths

  20. White roofs, cool-colored roofs save money OLD NEW AC savings ≈ 15% flat, white AC savings ≈ 5% pitched,cool & colored AC savings ≈ 10% pitched, white

  21. White roofs around the world

  22. …in Santorini, Greece 28 28

  23. …in Hyderabad, India …and widelyin the state of Gujarat, India. 29 29

  24. Walmart store in northern California 30 30

  25. Congratulations to UC Davis 31 31

  26. Solar-reflective surfaces cool the globevia “negative radiative forcing” Source: Intergovernmental Panel on Climate Change (IPCC) 32 32

  27. GLOBAL COOLING: making 100 m2 (1000 ft2) of gray roofing white offsets the emission of 10 t of CO2 33

  28. Answer: 24 Gigatonnes (Gt) 2/3 of a year’s worldwide emission Gigatonne = billion metric tons If implemented over 20 years (the life of a roof or a program) this is ≈ 1.2 Gt/year. How much CO2 equivalent is offset if we whiten all eligible urban flat roofs world-wide? (i/ii)

  29. Offset is equivalent to taking 300 million cars off the road for 20 years. There are about 600 million passenger cars world wide, and they each emit ≈ 4 t CO2/year. How much CO2 equivalent is offset if we whitenall eligible urban flat roofs world-wide? (ii/ii)

  30. Progress in energy efficiency standards In 2005, California’s “Title 24” energy efficiency standards prescribed white surfaces for low-sloped roofs on commercial buildings. Several hot states are following. In 2008, California prescribed “cool colored” surfaces for steep residential roofs in its 5 hottest climate zones. Other U.S. states & all countries with hot summers should follow.

  31. Recent cool roof progress (2005 – 2011) • 2005 • California Title 24 – “Flat roofs shall be white” (15 out of 16 climate zones). Walmart adopts white roofs for ALL stores. • EPA ENERGY STAR lists Cool Roof Materials • 2010 • June 1st, 2010 – Memo from U.S. Energy Secretary Steven Chucalls for all DOE Buildings to have white roofs, if cost-effective • June 16th, 2010 – Marine Corp follows suit, Pentagon following slowly • June 19th, 2010 – RetroFIT Philly announces winner of “coolest block” contest to white-coat black roofs of row houses. • 2011 • 100 Cool Cities launched – see www.WhiteRoofsAlliance.org • Spring 2011 – US will launch, at G20 Energy Ministers meeting, a voluntary Cool Roofs initiative and may even offer technical assistance to developing countries who join early.

  32. To come 2012… • Model codes will be modified to prescribe “flat roofs shall be white” • ASHRAE for commercial buildings • EECC for residential buildings • But states and cities have to adopt model codes

  33. Global Cool Cities Alliance could unitemany initiatives and trade associations

  34. Resources on the web • Art Rosenfeld’s website • ArtRosenfeld.org • Cool Colors Project • CoolColors.LBL.gov • Heat Island Group • HeatIsland.LBL.gov • Cool Communities Project • CoolCommunities.LBL.gov • Roof Savings Calculator • RoofCalc.com • Global Cool Cities Alliance • GlobalCoolCitiesAlliance.org • Cool Roof Rating Council • CoolRoofs.org • Cool California • CoolCalifornia.org • EPA Heat Islands • epa.gov/heatisland • Energy Star Cool Roofs • EnergyStar.gov February 2011

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