1. Renewable and Alternative Energy Leon County Schools 8 th Grade Comprehensive Science

2. What is Renewable Energy? An energy source that: – is replaced quickly by natural processes – is environmentally friendly and does not cause pollution – does not contribute to global warming – does not come from fossil or nuclear fuel – can not be depleted

3. Examples of Renewable Energy Solar Wind Tidal Hydropower Geothermal power Biomass

4. Solar Power Harnessing solar energy to produce electricity Positive: –The most abundant source of energy on Earth –Does not pollute the planet –With the right technology, could easily supply our current and future energy needs. Negative: –Some hazardous materials are used in the production of solar panels –Solar panels take up a lot of space. –Solar panels are expensive and are not very efficient yet

5. Wind Power Uses the power of the wind to turn turbines which produces electricity Positive: –Environmentally friendly –Low cost –Wind farms can be established on land or in the ocean Negative: –Only produces energy when the wind is blowing –Large turbines can injure birds and disrupt ecosystems due to noise

6. Tidal Power Tides are used to turn turbines to produce electricity -Positive -Non-polluting -Reliable and predictable -Negative: -low capacity for producing electricity -misses peak demand times -could disrupt or damage aquatic ecosystems http://www.youtube.com/watch?v=qRUl1mJQHmc&feature=player_embedded&list=PL7AC997353CC33B26

7. Hydropower Dams use the flow of water to turn turbines to produce electricity Positive: –Currently supplies 20% of the worlds electricity –Non-polluting –Low maintenance, low cost once built Negative: –Can cause a lot of damage to ecosystems around them –Takes years and a lot of money to build Image take from: www.clipartof.comwww.clipartof.com

8. Geothermal Uses heat found within earth to produce steam to turn turbines Positive: –Clean energy stored within earth –Cannot be depleted and is not harmful Negative: –High installation costs –Not available everywhere Image take from: abcteach.com

9. What is an Alternative Energy source? An energy source that: – may or may not come from natural processes. –can be depleted in some cases –may not have the undesirable effects of fossil fuels (pollution, etc) –May be more efficient than the current fuel used Image taken from: http://www.google.com/images

10. Examples of other Alternative Energy Sources Alcohols such as methanol and denatured ethanol Biodiesel Natural gas (compressed or liquefied) Propane Hydrogen Coal-derived liquid fluids

11. Biomass wood, waste, garbage, landfill gases and alcohol fuels are burned to produce heat and electricity Positive: –Abundant, found everywhere –Less CO 2 emissions than fossil fuels Negative: –Produces some air pollution (CO 2 ) –More expensive than coal Image taken from: http://cr.middlebury.edu/es/altenergylife/sbiomass.htm