RENEWABLE ENERGY Renewable Energy Resource - An essentially inexhaustible energy resource on a human time scale.

SOLAR HEATING Passive solar heating – captures sunlight directly with a structure and converts it to low-temperature heat for space heating. Active solar heating – specially designed collectors absorb solar energy (usually by heating liquids) and fan/pump distributes energy to parts of a building to meet space/water heating needs. Advantages 1.Saves money 2.Creates 2-5 more jobs/unit of electricity than other conventional sources 3.Eliminate/reduce fossil fuels 4.Less air pollution 5.Less environmental damage Disadvantages 1.Expensive initial costs 2.Aesthetically ugly? 3.Location-specific – latitude and orientation

PASSIVE SOLAR HEATING

ACTIVE SOLAR HEATING

HYDROPOWER Hydroelectric power plants – A dam is built across a large river to create a reservoir. The higher the head, the greater the amount of power that can be generated. Water is stored in a reservoir during low electricity production. Water is released and flows are controlled as electricity demands peak. Water spins the turbines in the “powerhouse” Examples – Hoover Dam on Colorado River, Three Gorges Dam in China Advantages 1.Moderate to high energy yield 2.Low operating/maintainence costs 3.Low air pollution times longer life than other power sources Disadvantages 1.Possibility to create floods 2.Destroys habitats/uproots people when dam is built 3.Pesticide/algicides necessary to prevent clogging of mechanisms 4.Decreased fish harvests 5.DO problems downstream

HYDROPOWER Hoover Dam

TIDAL POWER Tidal Power- power created from tidal energy – turbine spun as water flows back and forth Tides are more predictable than hydro/solar energies Few suitable sites High construction costs Single plant in US – went online Sept 2012 in Maine Very limited worldwide – France, South Korea, Canada South Korea has most tidal plants and has plans for installing many more

TIDAL POWER

BIOMASS Biomass – organic matter in plants produced through photosynthesis and can be burned directly as a solid fuel or converted into a gas or liquid fuel. 1.Burning wood 2.Agricultural Waste a)Bagasse (sugar cane residue) b)Straw 3.Urban Waste (WTE) - burning garbage 4.Biofuels a)Biogas – a mixture of 60% methane and 40% carbon dioxide. b)Liquid ethanol- (grain alcohol) – sugar + grain; mixed with gasoline, it can burned in conventional gasoline engines (super-unleaded) c)Liquid methanol – wood alcohol

BIOMASS WOOD GARBAGE BIOGAS BAGASSE SUGAR CANE

BIOMASS Disadvantages 1.Removal of trees depletes soil nutrients 2.Soil erosion (turbidity) 3.Flooding\ 4.Loss of wildlife habitats 5.Large land areas needed 6.Can have heavy pesticide/fertilizer use 7.Reduces biodiversity? 8.Reduces ecological integrity? Advantages 1.Potentially renewable 2.Less air pollutants released 3.Decreased use of fossil fuels 4.Moderate/high net energy yield

GEOTHERMAL Geothermal Energy - Heat contained in underground rocks and fluid that can be tapped for energy. Extracted dry steam, wet steam or hot water and can be used to heat space or water – needs to be at least 300°F “Potentially renewable resource” 22 countries currently use geothermal, it supplies 1% of world energy. In the USA (44% geothermal energy produced worldwide) geothermal electricity is produced mostly in Hawaii, California, Nevada, and Utah. Biggest plant world-wide is in CA – charges ~3 cents/kwh

GEOTHERMAL Disadvantages 1.Scarcity of reservoirs 2.Land subsidence 3.Potential air pollutants from water 4.Noise, odor Advantages 1.Reliable 2.Renewable 3.Moderate net energy yield 4.96% less CO 2 emitted 5.Competitive costs

GEOTHERMAL

Wind Power Modern turbines are relatively quiet - stay about 3x hub-height away from houses Limited impact on wildlife compared to other human influences Possible to interfere with radar because of reflectivity of blades

1.8% of the electricity in the U.S. is generated by wind turbines 50% of the renewable energy produced is wind enough to power 9.7 million homes cost averages 7 cents/kwh In the U.S., wind industry technician jobs surpassed coal mining jobs in Wind employment increased by 70% from 50,000 in 2007 to 85,000 in 2009 Wind Power

SOLUTIONS FOR SUSTAINABLE ENERGY Improve energy efficiency Increase local availability of renewable energy resources Find transitional resources (natural gas, nuclear?) Government must promote R&D for alternative renewable energy resources. Educate the public Government needs to implement constructive subsidies not destructive subsidies to promote change, this will lead to conservation of resources and less over-consumption.