Download - ES 79-Renewable & Alternative Energy Systems
ES 79- Renewable & Alternative Energy Systems
De Anza College- EMT ProgramSpring Quarter 2002
Stephen J. Murphy P.E.
Renewable and Alternative Energy Systems Solar Heating and Power Systems
Space Heating/Cooling Domestic hot water heating/swimming pools Photovoltaic (PV) Power
Wind Turbines/Energy Systems Ground Source Heat Pumps Fuel Cells Biomass
Renewable and Alternative Energy Systems
Solar Heating/Power systems: Solar “insolation” (incident solar radiation)
Energy balance Greenhouse effect “Solar constant”- 430 Btu/ft2/hr @ top of
atmosphere Solar geometry CRITICAL !
Altitude angle Azimuth angle
Solar Heating/Power SystemsHistorical Solar Energy Uses:
Steam generation/Steam engines Desalinization plants Solar cookers
Solar Heating/Power Systems“Present-Day” Solar Energy Uses:
1973 Oil Embargo “jump-started” business State solar tax credits initiated Utility rebates/low cost financing packages Domestic hot water (DHW) Space heating Photovoltaic Electricity Generation
Solar Heating/Power Systems“Active Solar” heating systems Solar Collectors
Low tech- i.e swimming pool (coiled plastic piping)
FPC design (Flat Plate Collector) Efficiency of collector is critical factor !
copper sheet with black selective surface; high absortivity/low emissivity
South facing Tilt angle = latitude
i.e. San Jose @ 37 0 tilt angle
Active Solar Heating Systems
System Types/Classifications: Forced air:
Rock bed thermal storage with forced convection fans Preheating for domestic water heating possible
Hydronics: Domestic hot water/swimming pool Space heating systems
Solar Heating/Cooling SystemsPassive Solar Heating/Cooling Systems:
Thermal Mass/Storage Solar geometry Summer shading devices
Overhangs Deciduous trees Mechanical blinds
Building envelope/insulation Natural convection (no fans/pumps)
Passive Solar Heating/Cooling Systems Direct Gain
Massive floor/wall design Water storage containers
In-direct Gain Trombe wall design Solar greenhouses Thermosiphoning