1. NIFA Conference 2011 “Solar Innovations” by Dr. Bing Chen University of Nebraska-Lincoln Passive Solar Research Group

2. Passive Solar Design Principles

3. Prairie Gold Homes - Base (24’x42’) with 2x4 stud walls 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 Base Case:

4. 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 Solar Version with Insulation: PGH Base with additional insulation and larger windows - south view (Cost: $6,500)

5. PGH Base - sunspace with insulation addition - south view (Cost: $12,500) 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 Sunspace (e.g., 15’x8’) Solar Version with Insulation:

6. 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/

7. Solar Example: Jerry McElroy Home - Straw bale construction with passive solar - Direct gain - Colorado http://renewablepowersolarenergy.com/solar-power/passive-solar-design

8. Modular-Prefab Home Example http://www.sbkinc.com/weblog/2006/05/the_modular_vacation_home_the.html - Wee house - Minnesota - $45k

9. Modular-Prefab Home Example http://www.thedailygreen.com/green-homes/latest/modular-homes-green-building-gorgeous - First LivingHome - Designed by Ray Kappe - Certified LEED Platinum - Approx. $230/sq ft

10. 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

11. 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