University of Colorado wins using TRNSYS

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Solar Decathlon

• University of Colorado wins using TRNSYS

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Acknowledgements

• This presentation is based on the following
  information
• Solar Decathlon Website
• University of Colorado Boulder website
• Detailed Simulation report,
• kindly communicated by Mike Wassmer

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Presentation Overview

• The Solar Decathlon
• University of Colorado project
• BASE
• Reduced environmental impact
• Systems
• TRNSYS Simulations
• Simulation approach
• Energy performance
• Other simulation tools

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What Is The Solar Decathlon?

• Competition to design, build and operate the most
  effective and efficient solar-powered house
• The 3 phases are evaluated!
• Self-sufficient (PV system batteries)
• Open to Students from US universities
• Some funding from DOE but mostly sponsors
• Houses are operated on the National Mall in
  Washington, D.C.
• First assembled in each university
• Must be easy to move
• No basement

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The 10 contests

• Design and Livability
• Innovation aesthetics
• Presentation Simulation report
• Graphics Communication
• Web site, newsletters, live tours
• The Comfort Zone
• Consumer appeal of HVAC system
• Performance of HVAC system (T, RH, Energy)
• Refrigeration

• Hot Water
• Shower/Laundry/Dishes
• Cons. appeal/Performance
• Energy Balance
• In/Out Batteries
• Lighting
• Innovation, Integration
• Performance
• Home Business
• Office space / equipment
• Getting Around
• Extra energy for transportation (elec. car)

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The BASE Design

• Adaptability through a modular approach
• Basic Module
• constructed from systematized wall, floor, and
  ceiling components called Structural Insulated
  Panels (SIP)
• Solar Decathlon 2 Basic modules (bed/bath and
  office/living areas)
• Spec Module
• Architectural customization
• Solar Decathlon Kitchen/Entry, high glazing
  fraction
• Tech Pod
• Utility module, metal frame

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The BASE Design

• What does it look like?

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Building

• More an every-day American home than a perfectly
  designed experimental solar house
• Roof is not at the perfect angle for solar
  cells17.5 and 25
• Not the 70s conventional passive design
• Environment-friendly building
• Materials
• Low embodied energy, sustainably harvested,
  recycled, recyclable, non-toxic, local suppliers
• E.g. fast-growing aspen wood, sheep wool,
  recycled plastic
• Construction
• Recycling, reducing waste

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Glazing

• SouthWall Superglass Quad-TC
• Double glazing 2 suspended films
• Krypton-filled
• weightless cavity constructionSame weight as
  double-pane window
• U-Value 0.57 W/m²/K
• Visible transmittance 52
• SHGC (Solar Heat Gain Coefficient) 41
• Glazing area
• 21 m², 50 in South façade

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Solar Thermal System (DHW only)

• Thermal collectors
• Evacuated Tubes placed on a flat surface
  (TechPod roof). Absorber is tilted
• 4.4 m², 300 l storage tank
• Electrical auxiliary heater 6kW

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PV System

• AstroPower mono-crystalline Si
• 60 m², 7.2 kWc
• Electrical System (48V DC)
• Maximum Power Point Tracker
• Lead-Acid batteries
• 4 parallel strings of 8 batteries
• 67.2 kWh total storage capacity
• Estimated cost 400 / month
• 30 years mortgage, 7 interest

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HVAC System

• All-electric
• Heat-pump
• 7kWth
• 5kW resistance for peak heating
• Ventilation system
• Energy Recovery
• Temperature
• Humidity

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TRNSYS Simulation study

• 3 independent simulations
• Solar Thermal system
• Usual SDHW system simulation
• Average Draw 135 l/day
• PV System
• Batteries were removed (perfect storage)
• Space conditioning Building
• Type 56 for building (1 zone)
• Different hypotheses on gains (home - home office)

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Solar Thermal System Simulation

• Parametric studies
• Collector area
• Location (CO, DC)
• Storage tank location
• Collector slope

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PV System Simulation

• Parametric studies
• Location (CO, DC)
• PV Array Azimuth
• PV Array slope

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Space Conditioning Simulation
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Building model

• Type 56 with some simplifications
• Tech Pod not modeled
• Windows approximated by existing model in US
  library
• Very low infiltration (0.05 ACH)
• Simplified shading simulation (lumped windows)
• Internal gains default values for Solar
  decathlon
• Setpoints
• Heating 20.6C
• Auxiliary electrical resistances 21.4C
• Cooling 24.7C
• ERV
• Constant effectiveness
• Schedule always ON for home office

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Space conditioning results
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Other simulations

• Early parametric studies
• Energy-10
• SIP thickness
• Glazing options
• Electric lighting design
• AGI32
• Solar Shading strategy
• Ecotect 5
• Daylighting
• Radiance

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More information

• Solar Decathlon website
• http//www.eere.energy.gov/solar_decathlon/
• University of Colorado Boulder Solar Decathlon
  Team website
• http//solar.colorado.edu/