Introduction to Agriculture, Food, and Natural Resources 1

2 Alternative Energy Introduction to Agriculture, Food, and Natural Resources Unit 6 – Lesson 6.2 The Greening of Energy

Current Energy Usage Fossil Fuels: Estimated energy usage in 2006 Petroleum 36.8% Coal 26.6% Natural gas 22.9% Amounting to 86% of fuel use. 3

Current Energy Continued Non-fossil Sources Hydroelectric 6.3% Nuclear 6.0% Geothermal, solar, tide, wind, wood, waste amount to 0.9% 4

Concern World energy consumption is increasing by approximately 2.3% per year. How will we continue to fuel the consumption needs of the world? 5

Renewable Energy Energy resources that are naturally replenishing but flow-limited Virtually inexhaustible Limited in the amount of energy that is available per unit of time 6

Alternative Energy Fuel sources that are other than those derived from fossil fuels. The term is typically used interchangeably for renewable energy. 7

Examples of Renewable Energy Ethanol – corn and biomass Biodiesel Nuclear Wind Solar Natural gas Hydrogen fuel cell Hydroelectric Tidal 8

A Closer Look at Energy Ethanol  Reduced soot released into the atmosphere  Produced from crops  Requires fuel to produce Solar  Naturally occurring  Easy to harness  Variable production  High start up costs 9

What is Solar Energy? Solar radiation produced by the sun that reaches the earth. Solar radiation can be converted to heat and electricity. 10

Electricity from the Sun Solar radiation can be converted to electricity with photovoltaic cells. Solar cells absorb light from the sun to produce electricity basics#solar_photovoltaics-basics

What effects solar energy output? Light Quality Light Intensity Angle of photovoltaic cell to the sun 12

13 References Burton, L. (2009). Environmental science fundamentals and applications. Clifton Park: Delmar. U.S. Department of the Interior. (2009). Renewable Energy Program. Retrieved October 11, 2009 from ns.htm ns.htm U.S. Energy Information Association. (2009). EIA energy kids: Solar. Retrieved November 30, 2009 from me-basics me-basics Wikipedia. (2009). Fossil fuel. Retrieved November 2, 2009 from