1. Alternative Energy

2. Solar Power Passive Solar –Building design using sunlight for heating Photovoltaics –Turn sunlight into electricity Power Towers –Mirrors focus sunlight to create steam for generator Limitations: –High installation costs –Pollution from PV cells –Night-time power???

3. Hydroelectric Power Hydroelectric Dams –Falling water turns turbine to generate electricity Benefits: Renewable Energy –Emit low levels of green house gases –Low operating cost, highly automated Drawbacks: Damage to Rivers –Block fish migration –Destroy stream, riparian, and floodplain habitat –Accumulate sediment, reduce dissolved oxygen

4. Wind Power Wind Turbines –Turbine runs generator for electricity Benefits: Renewable Energy –No air pollution –Expensive to install Environmental Concerns –Birds –Aesthetics

5. Biomass Fuels Renewable –Burned directly or converted to alcohol or methane Environmental Concerns –Emits greenhouse gases (shorter carbon cycle) –Pesticide and fertilizer pollution –Competition with food market –Net gain???

6. Geothermal Energy Using heat from earth’s geologically active sites Electrical generation –Use steam to turn turbine and run generator (piped or natural) Home and commercial heating –Hot spots of rising steam –Natural ground temperature

7. Hydrogen Fuel Cells How it works: –Hydrogen and oxygen converted to heat and water, produce electricity in process –Fossil fuels = current source of hydrogen Benefits –No emissions! (heat and water only) Implementation –Already in use; being developed for automobiles –Problems with fuel storage and transport http://www.howstuffworks.com/fuel-cell.htm