Renewable Energy SolarHydroWindHydrogenBiomassGeothermal

Energy Efficiency   Percentage of energy input that does useful work in an energy conversion system  Increasing energy efficiency of common devices has economic and environmental advantages Creating jobs, Saving money Reducing oil imports Prolonging fossil fuel supplies Reducing pollution and environmental degradation

Flow of U.S. Commercial Energy

Ways to improve Energy efficiency of Existing homes 1. adding insulation 1. adding insulation 2. plugging leaks 2. plugging leaks 3. installing energy-saving windows 3. installing energy-saving windows 4. wrapping water heaters 4. wrapping water heaters 5. installing tankless water heaters models 5. installing tankless water heaters models 6. buying energy-efficient appliances and lights 6. buying energy-efficient appliances and lights

Solar Energy Solar Energy No Pollution No Pollution Little maintenance Little maintenance  Only ~0.05% of world’s electricity. electricity. So why do we not Use it more? NOT ENOUGH gov’t aid

Solar- PV cells  Photovoltaic Cells commonly called solar cells  How do they work?  Sunlight energizes and causes the electrons in the semiconductors to flow creating an electrical current

Solar NEW technology 1. Organic solar cells- carbon based polymers similar to teflon and can be applied to surfaces in layers. - converts 24-35% of suns rays into electricity - converts 24-35% of suns rays into electricity  Can be printed on a sheet of paper, stuck onto your house

Solar NEW technology 2. Nanosolar Cells Tiny rods of semiconductors Much thinner than a human hair hair Can be placed in plastic materials materials

Suitability of Solar Usage best when more than 60% of daylight hours are sunny

Hydro  Indirect forms of RE  Pg 313

WIND Indirect form of RE Since 1990 fastest form of RE Europe the leader ¾ of World’s wind power wind power Denmark has banned coal and 90% of electricity from wind

WIND /  on page 397  The Dept. of Energy calls the Great Plain States: OK, SD, ND,KA,NE, TX the Saudi Arabia of wind  Enough wind resources to meet nations needs  Need more tax breaks and govt subsidies  Wind power could produce about ¼ of the U.S. electricity by 2025

Biomass  Plant material and animal wastes that can be directly burned into biofuels. 4 big types 1. Direct burning of wood or manure. Mostly used for cooking and heating homes. 30% in developing countries  10% efficient, produces CO2  10% efficient, produces CO2 figure figure 18-25

Biomass 2. Gaseous Biofuels Biogas 60% Methane, 40% CO2 60% Methane, 40% CO2 Comes from livestock waste and landfills AND with the bacteria and decomposition the Methane can used for electricity

Biomass 3. Ethanol- made from Sugar cane or Corn  How made? Fermentation and distillation  increase corn prices for farmers and lots of energy used to created it so a huge NET loss of Energy BUT… Ethanol can be made from non- food crops, grasses and other fast growing trees. Ethanol production from cellulose

Algae...next big biofuel  Algae make a lipid (oil) and the end of photosynthesis  After some refining….  

Geothermal Consists of heat stored in soil, underground rocks and fluids within the Earth’s mantle  Where? Throughout most of the world except the Tundra ~3m below the surface F Geothermal Heat Pumps A system of pipes and ducts into ground to exchange hot or cold temps depending on the season. 

Geothermal What about for Electricity? Tap deeper and more concentrated areas Found almost anywhere…5-6 miles below HOT DRY ROCK ZONES -magma heats up subsurface rock to high temps. Water is added onto rocks, steam produced, turn turbines= electricity ALSO,

Geothermal  Currently 1% of world uses GeoT  In Iceland 85% of all bldgs use GeoT  San Francisco “the Geysers” the worlds larges GeoT systems utilizes 1.7 million homes. In the Mayacamas Mountains, located north of San Francisco,

Hydrogen   Splitting water using ELECTROLYSIS under HIGH temps Problems 1. H locked in water and organic molecules like fossil fuels 1. H locked in water and organic molecules like fossil fuels 2. Takes $ and energy to extract the hydrogen 3. Current fuel cell models are expensive