A Sustainable Energy Future Renewable, Reliable, Clean, Efficient

Solar Energy Renewable Energy Source – THE Found every where at least part of the year. Four (4) Types:  Passive Solar Heating  Active Solar Water Heating  Solar Cells aka Photovoltaic cells  Solar Thermal Systems

Passive Solar Heating How it works: Build your home facing south. Large, double pane windows. Thick walls & insulation on north side. Concrete, adobe or stone construction. Venting for hot air out during summer. Drapes in winter to keep heat in at night. Deciduous trees planted on south side Block sunlight in summer Allow sunlight in winter

Passive Solar Heating

ADVANTAGES  Free energy  Renewable  Clean  Safe DISADVANTAGES  Unattractive  Is there enough available sunlight in all areas?  Construction costs  Requires backup heat source

Solar Water Heating (add this info on your chart underneath Passive Solar) How it works: “Solar Collectors” on roof Pipes with water or anti-freeze are coiled through box on roof. Heated water transferred to basement. Heat exchanged to fresh water; water pumped back to roof to be reheated.

Solar Water Heating

ADVANTAGES  Free energy  Renewable  Clean  Safe DISADVANTAGES  Unattractive  Is there enough available sunlight in all areas?  Requires a backup hot water source

Solar Cells (Photovoltaics) How it works:  Converts sunlight to electricity!  Sunlight strikes semi-conductor  Electrons are excited and move; creates electricity.  Energy can be stored in a chemical battery for use when sunlight is absent.

Photovoltaics (Solar Cells)

Photovoltaic Solar Cells ADVANTAGES  Free energy  Renewable  Clean  Safe DISADVANTAGES  Expen$ive!  Need large surface area  Unattractive  Is there enough available sunlight in all areas?  Requires a backup electricity source

Solar-Thermal Systems Used to generate High-temperature heat and electricity.  Central receiver = Power Tower! w/ heliostats  Solar thermal plant

Power Tower! Aka Central Receiver System

Solar thermal plant Oil-filled pipes collect the sun’s heat energy

Wind Energy How it works:  Sunlight heats Earth’s surface  Warm air rises; cooler air replaces it (wind)  Wind (mechanical E) turns giant blades  Connected to a generator; creates electricity

Wind Energy ADVANTAGES  Free energy  Renewable  Clean  Well developed technology  Electricity is cheaper per watt than coal produced. DISADVANTAGES  Unattractive  Few regions with consistent winds  Noisy  Interfere with microwave communications  Harm birds & wildlife

Wind Energy

Wind energy

Hydroelectricity How it works:  Dam is constructed to make a reservoir  Need height change to create enough power of moving water  Flowing water through dam turns turbines, turns generator, makes electricity

Hoover Dam

Hydroelectricity ADVANTAGES  Free energy  Renewable  Clean  Flood control  Reservoir for recreation & irrigation DISADVANTAGES  Disrupts ecosystems & floods upstream land  Tremendous environmental damage during construction  Dam construction is extremely expensive  Limited to areas with rivers & streams

Geothermal Energy How it works:  Uses Earth’s heat to create steam to make electricity  Hot Dry Rock Method Pump cold water below ground Turns to steam Extract pressurized steam Turns turbine, turns generator, creates electricity

Geothermal Energy

Geothermal Energy – Heat pumps Geothermal Heat Tubes

Geothermal Energy ADVANTAGES  Free energy  Potentially Renewable***  No greenhouse gases  Minimal environmental damage during set-up DISADVANTAGES  Limited availability on Earth.  Earth takes a long time to replace the heat.***

Biomass How it works:  Burn organic matter to produce heat  Examples: Wood (#1 in world usage) Municipal Waste (garbage) Sugar cane (Hawaii) Chicken droppings  Biofuels Gaseous liquid

Waste to Energy Plant

Biomass ADVANTAGES  Reduces “wastes”  Renewable  Conserves fossil fuels  Sell extra electricity to public DISADVANTAGES  CO 2 emissions  Noxious gases released  Who wants to live near a plant that burns trash or chicken poop?

Tidal Energy How it works:  Offshore Turbines Similar to underwater windmills  Tidal Barrage Similar to hydroelectric dams

Offshore Turbines

Tidal Barrage

Tidal Energy ADVANTAGES  Free energy  Renewable  Clean (non-polluting) DISADVANTAGES  Affects ecosystems  Unattractive  Expensive to build  Affects shipping

Hydrogen Fuel Cells Fuel source Decomposition of water 2H 2 O 2H 2 + O 2 Combustion 2H 2 + O 2 2H 2 O water Days or weeks Electricity, heat or light Storage and transport Electricity! Waste heat The Hydrogen energy cycle.

Hydrogen Fuel cells cars Nissan Honda Fueling Station

What’s Next? Choose. You Choose.