1 ES 79- Renewable & Alternative Energy SystemsDe Anza College- EMT Program Spring Quarter 2002 Stephen J. Murphy P.E.

2 Renewable and Alternative Energy SystemsSolar 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

3 Renewable and Alternative Energy SystemsSolar Heating/Power systems: Solar “insolation” (incident solar radiation) Energy balance Greenhouse effect “Solar constant”- 430 top of atmosphere Solar geometry CRITICAL ! Altitude angle Azimuth angle

4 Solar Heating/Power SystemsHistorical Solar Energy Uses: Steam generation/Steam engines Desalinization plants Solar cookers

5 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

6 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 tilt angle

7 Active Solar Heating SystemsSystem 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

8 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)

9 Passive Solar Heating/Cooling SystemsDirect Gain Massive floor/wall design Water storage containers In-direct Gain Trombe wall design Solar greenhouses Thermosiphoning