Energy Efficiency and Renewable Energy Technologies for Public Facilities

1. Energy Efficiency and Renewable Energy Technologies for Public Facilities September 8, 2004 Terri Walters State and Local Initiatives terri_walters@nrel.gov

2. High Performance Public Buildings: Overview • Design Process • Site Selection • Lighting & Daylighting • Building Shells • Mechanical Systems and Controls • Renewable Energy • Commissioning

3. DOE Zero Energy Buildings Vision • “By the year 2020, the United States will be constructing a significant number of buildings that: • meet their own energy needs by utilizing solar or other renewable resources, • have no on-site or off-site carbon emissions, • reduce utility peak electrical demand, • optimize the health and productivity of their occupants, • provide energy security from natural disasters and extended power outages.”

4. Zero Energy Buildings Systems Integration Building Technologies Solar PV and Solar Hot Water Technologies Efficiency Technologies & Building Integration Zero Energy Buildings Goal Fuel Cell Technology & Hydrogen Infrastructure Combined Heat and Power Technologies Hydrogen& Fuel Cells Distributed Energy

5. Whole Buildings Focus Evaluate a wide range of energy-efficient strategies,working together Passive solar heating Shading High Efficiency HVAC Daylighting Better HVAC Controls Better windows Economizer cycle Energy efficient lights and ballasts Reduced infiltration Lighting controls Reduced duct leakage Insulation Photovoltaics Thermal mass Distributed Generation Combined Heat and Power

6. Integrated Design • Modern Buildings function as complex systems • Whole building design is critical for success

7. Early Planning is Critical Opportunity Time

8. Design Process is Cross-Cutting

9. Design Consideration for Municipal Buildings • Ensure fiscal discipline • Energy efficient and self-generation reduces life cycle cost • Provide safe and healthy workspace • Building comfort increases productivity • Address reliable and secure energy supplies • Especially important for critical services and emergency facilities • Demonstrate community leadership • Municipal governments set the tone by using RE and EE

10. New Building Technologies • Cool and Green Roofs • Active and Passive Solar • Daylighting and lighting controls • High Efficiency Windows • Energy management and tracking systems • Onsite power generation

11. Green Roof Technologies Reduce Cooling Loads • Reduces cooling load (insulates) • Reduces stormwater runoff as well as cleans runoff • Reduces urban heat island effect

12. Cool Roofs • “Cool” roofs reduce cooling load by up to 40% • Reflect sun’s thermal energy instead of absorbing it • Reduces urban heat island effect

13. Solar Thermal Systems • Solar collectors produce heat for many applications • Domestic hot water • Pool heating • Space heating • Absorption cooling • Can provide 40%-80% of building needs

14. Solar Thermal for Cooling: Absorption Chillers • Texas has excellent solar resources but mainly needs cooling, not heating. • Absorption Chillers can use solar thermal collectors as a heat source. • Absorption chillers used extensively in New York. • Hybrid Solar/Fossil absorption chillers available. • Austin Energy’s Sand Hill building uses solar absorption chillers.

15. Solar Thermal for Air Heating • Transpired Solar Collectors are solar air preheating systems • Collector is dark metal wall with holes • Typical system payback 3-12 years

16. Desiccant Cooling Systems • Non CFC, energy efficient space conditioning • Heat driven, like absorption cooling • Dehumidifies and cleans the air, making it useful for hospitals and other clean air environments • Perform best in humid environments

17. High Efficiency Windows • Texas SB 5 requires windows with a Solar heat gain coefficient (SHGC) of 0.40. • SHGC measure how much solar heat is allowed through the window. Lower is better! • Current Texas buildings average .73

18. Diffusing Skylights • Diffusing skylights can reduce both electric and cooling loads. • Skylights reduce electric loads by replacing lighting • Reduce cooling loads through reflectivity as well as reduced heat loads from lighting.

19. Daylighting Strategies Help Reduce Electrical Loads

20. Daylighting and Lighting Controls can be used throughout the building

21. Integration of Lighting and Lighting Controls • Integration of natural daylighting, artificial lighting and lighting controls is important • Note the natural daylight is indirect • avoids glare problems • reduces direct heat gain

22. Ground Source Heat Pumps • Heat Pumps make use of the constant temperature of the earth • Fluid is pumped through pipe loops placed underground • Can be used for heating and cooling.

23. PhotovoltaicsBuilding Integrated • 4 Times Square, NYC • Demonstration of several energy technologies • PV Curtain Wall on upper floors

24. Building-Integrated PV • Any PV system can be integrated with a building • Building Integrated PV tends to have lower efficiencies than standard PV • NREL research is focused on raising these efficiencies.

25. Integrated PV Examples

26. Energy Management Controls • EMC optimize performance of all buildings systems • Complex array of sensors and controls to ensure efficienct use of energy. • Balance Economizers, Variable Air Volume fans, Daylighting & Lighting

27. On-Site Power Generation • Power Quality Power Reliability • Critical Government services • Hospitals • Communications • Emergency services Courtesy Powerlight Corporation

28. Combined Heat and Power • Combining heat and power increases efficiency • Future of CHP • Microturbines • Fuel Cells

29. Case Studies

30. Pennsylvania DEP: Cambria Office Building • Energy Efficient Features • Efficient envelope • Under-floor air distribution system • Ground-source heat pumps • 18 kW PV system • Daylighting / lighting system 30% energy savings 87 EnergyStar Rating

31. Jefferson County, CO District Attorney Building • 52,000 square feet • Daylighting • Passive Solar • High-quality, low cost

32. Foothills Community HospitalBoulder, CO • First LEED Hospital • Silver certified • Combined Heat and Power • Efficient HVAC and Lighting • White Roof • Water Conservation • Green Power

33. Galt House, Lousville KY • World’s largest Ground Source Heat Pump project • GHP system cut energy use in half in 750,000 sq. ft. hotel • Savings • 20-50% on installation • $25,000/mo. on energy • 25,000 sq.ft. space • 15 years of success

34. Low Temperature Solar Hot Water: Barnes Field House, Fort Huachuca, AZ • 2,000 square feet of unglazed collectors • Meets 49% of pool heating load • Installation: $35,000 • Annual savings: $5,400 • Older project, 1980

35. High Temperature Solar Hot Water:Social Security Admin. Philadelphia. • Reheats Recirculation Loop • Cost $58,000 • Delivery of 143 million Btu/year estimated • Installed 2004.

36. High Performance Buildings: Texas • Austin City Council resolution in 2000 • All new municipal buildings LEED Silver • New green buildings: • Austin Energy: Sand Hill Center • Austin Library: Carver Branch • Combined Emergency Center

37. Future Austin Green Buildings

38. Summary • Buildings are complex systems and require an Integrated Design Process • Early planning crucial • EE and RE innovations make Zero net energy achievable • Leverage existing as well as emerging technologies • Public buildings can lead the way for a more efficient building sector.