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Madigan Home Tour and Solar Energy Seminar. By David W. Madigan, P.E. Why Renewable Energy?. USA uses an Inordinately High Share of Energy on a Per Capita Basis USA uses 40% of World-wide Energy Flows and Generates 33% of CO2 and Associated Pollutants World-wide
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Madigan Home TourandSolar Energy Seminar ByDavid W. Madigan, P.E.
Why Renewable Energy? • USA uses an Inordinately High Share of Energy on a Per Capita Basis • USA uses 40% of World-wide Energy Flows and Generates 33% of CO2 and Associated Pollutants World-wide • Buildings use 1/3 of Total US Energy and 2/3 of Electricity • World-wide Fossil Fuel Reserves are Being Depleted at an Alarmingly Increasing Rate
Conservation vs. Generation • Conservation preferable over Renewable energy • Usually Better Economics • Even Renewable Energy has Environmental Consequences • Conservation Measures Result in Reduction of Usage and Peak Loads • Conservation and Renewable Energy Complement One Another • Renewable Energy Capital Intensive • Conservation Reduces Capital Investment by Limiting Peak Loads • Implement Renewable Energy Systems after Making Maximum use of Conservation Options – Sustainable Design Process
Solar Energy • Solar Energy is the Basis for Essentially all Renewable Energy Sources • Solar Energy Incident On Earth Annually: • 160 Times the World’s Proven Resources of Fossil Fuels • 15,000 Times the World’s Annual Use of Energy • Solar Energy can be used Directly: (solar thermal, photovoltaics, daylighting) or Indirectly: (wind, geothermal, biomass)
Solar Energy Basics • Sun is a High Temperature “Radiator” (6000°C) • Earth is a Low Temperature “Receiver” • Solar Energy is Received as Short Wavelength Radiation • 30% Reflected by Atmosphere • 70% Re-radiated As Long Wavelength Radiation • Atmosphere Acts like Glass on a Solar Collector
Solar Energy Basics • Incident Solar Energy Varies Based on: • Length of Travel Through Atmosphere • Latitude, Seasons • Atmospheric Clarity • Cloud Cover, Pollution • Time of Day • Angle and Orientation of Collector Surface • Sun Angle Highest in Summer (73.5°) and Lowest in Winter (26.6°) (at 12:00 pm, 40° lat.)
Seasonal Solar Angles Connecticut: Highest Summer 73º Lowest Winder 27º
Solar Energy Basics • Direct & Diffuse Radiation • Beam Radiation from Sun Scattered when Penetrating Atmosphere • Flat Plate Collectors, Passive Solar & Daylighting Makes Use of Both Direct & Diffuse Radiation • Concentrating Collectors use Primarily Beam Radiation • Ratio of Beam to Diffuse Varies by Local Climate • Cloudier Climates ~ 50% beam / 50% diffuse • Clear Climates ~ 80% beam / 20% diffuse
Solar Thermal Energy • Active Solar Heating • Passive Solar Heating • Solar Thermal Engines • Daylighting
Solar Thermal Collectors • Dark Surface with High Absorptance Gathers Full Spectrum of Solar Radiation • Heat is Drawn Away by Working Fluid – Usually Glycol / Water • Glass and/or Selective Surface Used to Minimize Conduction and Re-radiation Losses • Efficiency Dependant on Collector Design and Working Temperature • Lower Temperature = Higher Efficiency
Efficiency (%) Fluid Temperature Above Ambient Collector Efficiency
Active Solar Thermal Systems • Domestic Hot Water Heating • Pool Heating • Space Heating • Make-up Air Preheat • Thermal Based Cooling
Domestic Hot Water Application Considerations • Low Temperature Operation Allows High Collector Efficiency, Year Round Loads • Storage Requirements Dependent on Use Profile • Back-up Heating Required – Inexpensive • Typical Residential System: 70-100 SF Collector, 80-150 gal. Storage • Consider Freeze Protectionand Over Collection Issues
Pool Heating Application Considerations • Highest Operating Efficiency • Applicable for Indoor or Outdoor Pools • Consistent Year Round Loads for Indoor Pools • Outdoor Pools – Inexpensive Unglazed Collectors • Indoor Pools – Need Higher Efficiency Collectors for Winter Operation • No Heat ExchangerRequired for OutdoorPools
Space Heating Application Considerations • Lowest Solar Resource and Collector Efficiency at Time of Highest Loads – Daily & Annually • Need High Efficiency Collectors • Good Application with Low Temp Radiant Heating • Couple with Passive Solar • Storage Required to Offset Nighttime Loads • High Efficiency Envelope Design Minimizes Heat Loads / System Sizing • Can be Coupled with Summer Thermal Air Conditioning
Thermal Based Cooling Application Considerations • Peak Loads Coincide with Maximum Solar Resource – Annually and Daily • Provides Fairly Consistent Year Round Load when Coupled with Space Heating • Requires High Temperature Solar System Operation • Thermal Based Cooling Equipment – Expensive and Inefficient (COP ~ .6 – 1.0) • PV / GSHP may be Preferable
Daylighting Overview • Solar Resource Used to Offset Highest Cost Electricity • Technology Well Developed • Allows Reduced Cooling Loads Also • Can Help to Downsize HVAC Systems • Glazing Optimization by Exposure • Need to Control Excess Solar Heat Gain • Best Implemented as Part of an Integrated Design Process • Can Be Highly Cost Effective • Improves Indoor Environment • Can Combine with PV Technology & Passive Solar Design
Photovoltaic (Solar Energy) Systems • Electricity Production Directly From Sunlight • Utilizes Photon Energy in Sunlight to Promote Electrical Current Flow • Relies on Semi-Conductor Effects in Specialized Materials • DC Power Output from Panels • Extensive Development of New Technologies & Products Underway
Types of PV Modules Mono-crystalline Thin Film on flexible substrate Poly-crystalline Thin Film on glass substrate
Crystalline PV Modules Output: 10-15 watts/SF Efficiency: 12% - 18% Color: blue / black Module sizes: 5 watts – 300 watts Reduced efficiency under hot conditions Longer track record in field Thin Film Modules Output: 5-8 watts/SF Efficiency: 6% - 8% Color: gray to black, deep blue Module sizes: 5 watts – 120 watts Less efficiency drop under hot conditions More efficient in low light conditions Crystalline vs. Thin Films
Solar: Big Company Players • Shell Oil – Solar subsidiary • Kyocera • Sharp • Sanyo Electric • BP Oil – Solar subsidiary • AstroPower (Division of GE Power) • Sunpower Lots of New Players & Development Underway
PV System Elements • PV Panels • Mounting System • Electrical Interconnection • Voltage Regulation Device for Direct DC Load Application • DC-to-AC Inverter for Traditional AC Applications • Energy Storage System for Off-Grid and/or Emergency Back-up Applications • Additional Grid Interface |Components if Required by Local Utility
PV Components Grid-tied System
Roof Mounted PV Systems • 2 kW Array • (16)120-wattModules • Low-profileMounting • Mounts OverExisting Roof • “Raised” to AllowAir Movement
BIPV Roofing Products Atlantis Sunslates • Installs Over Wood Batten System • Replaces Conventional Roofing • 12 Watt Modules • Venting Required for Air Movement
BIPV Roofing Products Uni-Solar Standing Seam Metal Roof • Laminates on Standard Standing • 120 Watts per Panel (19’ length) • 6-8 Watts per SF
BIPV Roofing Products Uni-Solar Standing Seam Metal Roof • ECD Thin FilmLaminate • 2 kW Output • Grid Connect U-I System with Net Metering
PV Energy Concepts • Performance Factor Considerations • Perpendicular Solar Incidence will Yield Highest Output • Solar Array Tilt Selection can Optimize Seasonal Performance • Tilt 20º - 50º may Optimize Year Round Performance • Colder Ambient Temperatures will Increase Efficiency • Shading Effects of Collector Arrangements and Adjacent Buildings will Reduce Output • Tree Shading Effects may not be Excessive if Deciduous Trees are Involved, Analysis Required.
PV Energy Concepts • Site Performance Estimates
PV Energy Concepts • System Cost Breakdown • PV Panels ~ 55 - 60% • Inverter & Electrical Components ~ 20 - 30% • Labor ~ 15 - 20% • Typical System Cost $ / w4 kW • Total Installed Cost $8-10/w $36,000 • CCEF Rebate $5.50/w $20,000 • Tax Refund $.50/w $2,000 • Net Cost to Homeowner $3-4/w $14,000
Solar Thermal / PV Comparison Solar DHWPV Panel Efficiency 60 – 80 % 12 – 18 % Panel Cost $15 – 25 /s.f. $40 – 60 / s.f. Peak Output 50 – 60 w/ s.f. 9 – 15 w/ s.f. System Cost $80 – 120 / s.f. $90 – 130 / s.f. $1.50 – 2.50 / w $8 – 10 / w Annual Output (CT) 65 – 85 kwh/s.f./yr 14 – 18 kwh/s.f./yr Rebate $2000 $5 / w + $2000 Offset Energy Cost ($3.00/gal.) / ($0.18 kwh)$0.18 /kwh Annual Savings $6.50/s.f. / $13.50/s.f. $3.00/ s.f. Simple Payback 15 yrs./ 8 yrs. 15 yrs. ROI 10% / 20% 10%
Solar Power Information • American Solar Energy Society, ases.org • Interstate Renewable Energy Council, irecusa.org • Million Solar Roofs, millionsolarroofs.com • National Renewable Energy Laboratory, nrel.gov • Solar Electric Power Association, solarelectricpower.org • Solar Energy Industry Association, seia.org • Institute for Sustainable Power, ispq.org • US Dept. of Energy Office of Renewable Energy, eren.doe.gov
Madigan Home Energy Features Overview • Passive Solar • Thermal Mass • Super Insulation • Natural / Mechanical Ventilation • Solar Thermal Domestic Hot Water / Hot Tub • Photovoltaic System • Wood Heating System • Bio-diesel Fuel Storage
Madigan Home Passive Solar Features • Orientation: 20º East of South • Dimensions: 60’x24’, Long E/W Axis • Extensive South Glazing • Limited N, E, W Glazing • Garage on North • Vertical Glazing Optimizes Winter / Summer Performance • Sunroom Direct Charging of Mass • Arbor for Summer Shading
Madigan Home Energy Conservation Features • Stress Skin Walls • 4” Polyurethane - R30 • Roof and Attic • Attic: 18” Fiberglass – R60 • Roof: 12” Fiberglass + 1 ½” ISO – R45 • Foundation / Basement • Floor: 1” Polystyrene – R6 • Foundation below grade: 2” Polystyrene – R12 • Foundation above grade: 3” Polystyrene – R18 • Windows • South Side: Double Glazed, Low-e, Argon – R3.5 • Other Sides: Triple Glazed, Low-e, Argon – R5
Madigan Home Natural / Mechanical Ventilation • No Air Conditioning • Extensive Operable Window Area • Chimney Effect through Third Floor • Arbor & Overhangs for Shading • Thermal Mass Fly Wheel Effect • Nighttime Cooling via Whole House Fan • Ceiling Fans in Kitchen and Bedrooms
Madigan Home Thermal Mass • Exterior Insulation of Basement Walls • Brick Walls Around Sunspace • Concrete / Slate Floor in Sunspace • Gravel Below Sunroom Floor • Massive InteriorFireplace
Madigan Home Oil / Wood Heating System • 100 MBH Oil Fired Boiler (B-20 used) • Boiler Feeds Fan Coil Units, DHW Tank and Hot Tub • Vermont Castings Wood Stove • Recirculation from Woodstove or Solar Greenhouse • Air to Air Heat Exchanger • Dryer Recirculation into 2nd Floor Area • Oil use – About 300 gal/yr for Heating and DHW • 2 to 3 Cords of Wood
Madigan Home Solar Thermal Domestic Hot Water / Hot Tub • 2/3 4’x10’ AET Collectors • 120 Gallon Insulated Storage Tank • Glycol / Drainback System • Drainback Tank in Attic • 95% DHW Load in Spring / Summer / Fall • Preheats DHW in Winter • Heats Hot Tub Also
Madigan Home Photovoltaic System • 5.5 kW Peak DC Output (STC) • 28 Sanyo BA-195 Collectors • High Collector Efficiency (17%) • Highest PTC Rating • Fronius IG-5100 Inverter • Anticipated Output: 6500 - 7000 kwh/yr • $25,000 CCEF Rebate
Madigan Home Bio-Diesel Fuel Storage • 330 Gallon Tank w/ Electric Pump • B-100 Used April through November • B-20 Used in Winter • Supplies a 4 person “Co-op”
Madigan Home Future Improvements • Install Third Solar Thermal Collector • Moveable Insulation on Larger Windows • Solar Air Heater on Living Room Wall • Reduce Infiltration • LED Lighting • Condensing Oil Boiler • Replace Refrigerator