Renewable Renewable EnergyEnergyChapter 18

18-1 Renewable Energy 18-1 Renewable Energy TodayTodayObjectives

1. List six forms of renewable energy, and compare their advantages and disadvantages. 2. Describe the differences between passive solar heating, active solar heating, and photovoltaic energy. 3. Describe the current state of wind energy technology. 4. Explain the differences in biomass fuel use between developed and developing nations. 5. Describe how hydroelectric energy, geothermal energy, and geothermal heat pumps work.

Renewable Energy – energy from sources that are constantly being formed

Solar, wind, hydro, and geothermal

Solar EnergyMost all renewable energy comes directly or indirectly from the sun

◦Passive Solar EnergyUse the sun’s energy to heat something directly

Characteristics of a passive Characteristics of a passive solar homesolar home

Ceilings heavily insulatedThick walls and floorsSouth-facing double paned windowsShade trees for summerInsulated windows

◦Active Solar HeatingUses collectors to gather the sun’s energyCollectors on roofs capture the sun’s energy and heat a liquid which flows to a heat exchanger which heats water for the building

About 8% energy used in US is used to heat water

Photovoltaic cells convert the sun’s energy into electricityNo moving partsProduce a small electric current

Need extended periods of sunlightElectricity stored in batteries

Provides about 1 million households with electricity worldwide

Concentrated Solar Concentrated Solar ThermalThermal

300 foot Power Tower near Seville, Spain

Concentrated Solar Concentrated Solar ThermalThermal

300 foot Power Tower near Seville, Spain

Olmedilla Photovoltaic Park - Spain

280 acres

162,000 pv panels

Electricity for 40,000 homes

15 of 20 largest solar power plants in the world

Nellis Solar Farm, Nevada

Solar updraft tower - Australia

Wind PowerConverts the movement of wind into electrical energy

Faster growing energy source

Tehachapi Wind Turbines

Number of MWatts by state, March 2007

As of third quarter, 2009 there are 31,100 MW of electricity produced by wind in US

Biomass When plant material, manure, or any other organic matter is used an energy source◦Include wood and dung (can cause air pollution and habitat destruction)

◦Other sources of biomass include methane (gas given off by decomposition) and alcohol (ethanol- fermentation of agriculture wastes)Gasohol – blend of gasoline and ethanol; less air pollution than gas

Hydroelectricityenergy produced by moving water

20% of the world’s electricity

Dams are expensive to build but inexpensive to operate

Advantages: No air pollution, provide flood control, water for drinking, agriculture, industry, and recreation

Disadvantages: disrupts ecosystems, displacement of people, potential for dam failure, sedimentation

Hydroelectric dams are the standard when we think of hydro power

Wave powered electrical generators

Geothermalenergy from the heat in the Earth’s crust

Pump water heated water from rock formations and use the water or steam to power turbines

Some homes use geothermal heat pumps

US is the world’s largest producer of geothermal heat pumps

18-2 Alternative Energy and 18-2 Alternative Energy and ConservationConservationObjectives1. Describe three alternative energy

technologies. 2. Identify two ways that hydrogen

could be used as a fuel source in the future.

3. Explain the difference between energy efficiency and energy conservation.

4. Describe two forms of energy-efficient transportation.

5. Identify three ways that you can conserve energy in your daily life.

Look around the room…..can you find any instances were energy is being wasted??

Alternative energy- describes energy sources that are still in development

Tidal PowerUses the 2 tide changes

Tide difference needs to be around 16 m

Cost to build is high

Ocean Thermal Energy Convection

Warm surface water is used to boil sea water◦Water at lower pressure boils at a lower temperature

◦Boiling water turns turbine

◦Expensive to operate

◦Environmental effects unknown

HydrogenoHydrogen is found in every molecule of every living thing

oProduces water vapor as a byproduct

oTakes energy to produce the pure hydrogen

Energy can be stored in fuel cells (produces electricity chemically)

Honda FCX Clarity

Energy EfficiencyHow do we reduce energy use?◦Lifestyle changes◦Upgrade distribution grid◦Upgrade industrial motors

◦Newer steel manufacturing methods

◦Recycling

◦Increase energy efficiencyThe percentage of energy put into a system that does useful work

energy out/energy in X 100

More than 40% of energy produced is wasted

Super Grid technologyAllows for mixed use of stable and

intermittent energy sourcesUtilizes electricity storage

technologyHigher efficiency in delivering

electricity over long distancesDecentralization of electricity

generating plantsClose or reduce usage of coal-fired

electric plantsDuke Power, Smart meters

Decrease dependence on fossil fuels

Use public transportationUse more energy efficient vehiclesHybrid cars - Toyota Prius, Honda (Civic, Fit, CR-Z) Tesla Roadster, Fisker Karma, Chevy Volt, Hyundai Sonata, Ford Fusion, etc.

Cogeneration◦The production of two useful forms of energy from the same fuel sourceUsing waste gases and heat for electricity and heating and cooling

Why cogeneration?More efficient use of primary fuelCuts energy costsReduces CO2 emissionsIncreases corporate and utility

profitsIncreases the GDP

What prevents cogeneration?Current utility laws in 42 statesCorporate reluctance to invest in

new electric enginesAbsence of specific tax and

program subsidies from Federal government

Energy Conservation◦SAVING ENERGY! Use energy efficient devices Walk or Carpool Buy products that use less packaging

Recycle between 1990 and 2000 US trashed 50 billion aluminum cans, enough to rebuild the worlds entire commercial airfleet 25 times

9 aluminum, plastic or glass containers every week on avg for every person in the US = 53.5 million barrels of oil each year

Lower your thermostat (68 in winter, 78 in summer)

Unplug unused electrical appliances

Clean ventsWater saving devicesWHAT CAN YOU DO???