Energy Efficiency and Renewable Energy Technologies for Public by wuxiangyu


									Energy Efficiency and Renewable
     Energy Technologies
      for Public Facilities
          September 8, 2004

              Terri Walters
       State and Local Initiatives
       High Performance Public
         Buildings: Overview
• Design Process
• Site Selection
• Lighting & Daylighting
• Building Shells
• Mechanical Systems
  and Controls
• Renewable Energy
• Commissioning
  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.”
          Zero Energy Buildings Systems

                Building               Solar

 Efficiency Technologies                    PV and Solar Hot
  & Building Integration                    Water Technologies

                            Zero Energy
                           Buildings Goal
Fuel Cell Technology &                      Combined Heat and
Hydrogen Infrastructure                     Power Technologies
                Hydrogen &          Distributed
                 Fuel Cells           Energy
   Whole Buildings Focus
Evaluate a wide range of energy-efficient strategies,
                  working together

                      Passive solar heating
                                 High Efficiency HVAC
                                      Better HVAC Controls
  Better windows
Energy efficient lights                   Economizer cycle
    and ballasts                          Reduced infiltration
 Lighting controls                       Reduced duct leakage
       Insulation                     Photovoltaics
         Thermal mass          Distributed Generation
                     Combined Heat and Power
            Integrated Design

• Modern Buildings
  function as complex
• Whole building
  design is critical for
              Early Planning is Critical

Design Process is Cross-Cutting
       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
    New Building Technologies

• Cool and Green Roofs
• Active and Passive Solar
• Daylighting and lighting controls
• High Efficiency Windows
• Energy management and tracking
• Onsite power generation
  Green Roof Technologies Reduce
          Cooling Loads
• Reduces cooling
  load (insulates)
• Reduces stormwater
  runoff as well as
  cleans runoff
• Reduces urban heat
  island effect
                 Cool Roofs

• “Cool” roofs reduce
  cooling load by up to
  – Reflect sun’s thermal
    energy instead of
    absorbing it
  – Reduces urban heat
    island effect
           Solar Thermal Systems

• Solar collectors produce
  heat for many
   –   Domestic hot water
   –   Pool heating
   –   Space heating
   –   Absorption cooling
• Can provide 40%-80%
  of building needs
     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.
    Solar Thermal for Air Heating
• Transpired Solar Collectors are solar air preheating
• Collector is dark metal wall with holes
• Typical system payback 3-12 years
      Desiccant Cooling Systems

• Non CFC, energy
  efficient space
• Heat driven, like
  absorption cooling
• Dehumidifies and
  cleans the air, making it
  useful for hospitals and
  other clean air
• Perform best in humid
         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
• Current Texas buildings
  average .73
              Diffusing Skylights

• Diffusing skylights can
  reduce both electric and
  cooling loads.
   – Skylights reduce electric
     loads by replacing
   – Reduce cooling loads
     through reflectivity as
     well as reduced heat
     loads from lighting.
Daylighting Strategies Help Reduce
          Electrical Loads
Daylighting and Lighting Controls can
  be used throughout the building
          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
    Ground Source Heat Pumps

• Heat Pumps make
  use of the constant
  temperature of the
  – Fluid is pumped
    through pipe loops
    placed underground
  – Can be used for
    heating and cooling.
Building Integrated
     • 4 Times Square, NYC
     • Demonstration of several
       energy technologies
     • PV Curtain Wall on upper
          Building-Integrated PV

• Any PV system can
  be integrated with a
• Building Integrated
  PV tends to have
  lower efficiencies
  than standard PV
• NREL research is
  focused on raising
  these efficiencies.
Integrated PV Examples
    Energy Management Controls

• EMC optimize
  performance of all
  buildings systems
• Complex array of
  sensors and controls to
  ensure efficienct use of
• Balance Economizers,
  Variable Air Volume
  fans, Daylighting &
      On-Site Power Generation

• Power Quality
  Power Reliability
  – Critical Government
  – Hospitals
  – Communications
  – Emergency services
                          Courtesy Powerlight Corporation
     Combined Heat and Power

• Combining heat and
  power increases
• Future of CHP
  – Microturbines
  – Fuel Cells
Case Studies
                 Pennsylvania DEP:
               Cambria Office Building
• Energy Efficient Features
  –   Efficient envelope
  –   Under-floor air distribution system
  –   Ground-source heat pumps 30% energy savings
  –   18 kW PV system
  –   Daylighting / lighting system 87 EnergyStar Rating
          Jefferson County, CO
        District Attorney Building
•   52,000 square feet
•   Daylighting
•   Passive Solar
•   High-quality, low
  Foothills Community Hospital
           Boulder, CO
• First LEED Hospital
   – Silver certified
• Combined Heat and Power
• Efficient HVAC and Lighting
• White Roof
• Water Conservation
• Green Power
        Galt House, Lousville KY

• World’s largest Ground
  Source Heat Pump
• 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
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:
                     Older project, 1980

High Temperature Solar Hot Water:
Social Security Admin. Philadelphia.

                   • Reheats Recirculation
                   • Cost $58,000
                   • Delivery of 143 million
                     Btu/year estimated
                   • Installed 2004.
       High Performance Buildings:
• 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
Future Austin Green Buildings

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

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