Transcript NIFA Conference 2011

NIFA Conference 2011
“Solar Innovations”
by Dr. Bing Chen
University of Nebraska-Lincoln
Passive Solar Research Group
Passive Solar Design Principles
Prairie Gold Homes - Base (24’x42’) with
2x4 stud walls
Base Case:
• R-13 walls and R-20 roof, BLC = 8191 BTU/degree-day in Chadron, NE (6774 DD)
with indoor design temp of 70°F and outdoor design temp of -3°F.
• Yearly load = 52.6 M BTU or 1535 KWH @ $0.10/kwh = $1535 annual heating bill
TIF = 7.2 BTU/DD-SF
PGH Base with additional insulation and
larger windows - south view (Cost: $6,500)
Solar Version with Insulation:
• R-30 walls and R-50 roof and 60 SF south windows and R-3 all windows
• Yearly load = 12.85 BTU or 3750 KWH or $375 annual heating bill TIF = 1.9
• ROI = $6.5K /( $1535-$375) = 5.6 years
PGH Base - sunspace with insulation
addition - south view (Cost: $12,500)
Sunspace (e.g., 15’x8’) Solar Version with Insulation:
• 120 SF sunspace @ $50/SF Yearly load = 12.8 MBTU or 3730 KWH (not insulated),
9.4 BTU or 2750 KWH (insulated)
• Annual heating bill $373 ($275 insulated) ROI = $12.5K / ($1535 - $275) = 10 years
Solar Example: Malibu 5
Beach House
- Pacific Coast
- $1.3M
http://www.ecofriend.org/entry/eco-architecture-kanner-architects-malibu-5-home-keeps-you-close-to-nature/
Solar Example: Jerry McElroy Home
- Straw bale
construction with
passive solar
- Direct gain
- Colorado
http://renewablepowersolarenergy.com/solar-power/passive-solar-design
Modular-Prefab Home Example
- Wee house
- Minnesota
- $45k
http://www.sbkinc.com/weblog/2006/05/the_modular_vacation_home_the.html
Modular-Prefab Home Example
- First LivingHome
- Designed by Ray Kappe
- Certified LEED Platinum
- Approx. $230/sq ft
http://www.thedailygreen.com/green-homes/latest/modular-homes-green-building-gorgeous
Conclusions
• Passive Solar is a low-cost option that should be
considered in residential construction with prefabrication
• Payback times can be 5 years or less
• “Green” and renewables are “in” and may be strong
selling points to customers of all economic levels
• Different solar options include different passive
techniques, PV for power, active flat plates for domestic
hot water heating
References
• Path to Passive: Nebraska’s Passive Solar Primer
• Bing Chen et al., 1982
• http://www.neo.ne.gov/publications/pathtopassive.htm
• Nebraska Residential Solar Architecture
• Bing Chen et al., 1983
• http://www.neo.ne.gov/publications/solar_architecture.htm