Renewable Energy Sources

Cleaner Cars, Cleaner Fuels Cars release a lot of pollution Cars release a lot of pollution Bush administration Bush administration 7% improvement in mileage 7% improvement in mileage 22.2 mpg 22.2 mpg Diesel engines need work Diesel engines need work

Electrical Generation Costs

Solar Energy Energy directly from the sun Energy directly from the sun Pros Pros Tremendous amount Tremendous amount Always available Always available Doesn’t pollute Doesn’t pollute Cons Cons Must be collected Must be collected Expensive to set up Expensive to set up

Passive Solar Heating No mechanical devices to distribute heat No mechanical devices to distribute heat New home design New home design Room temperature is steady Room temperature is steady Convection Convection Save on heating! Save on heating!

A Passive Solar Home

Photovoltaic (PV) Solar Cells Convert sunlight into electricity Convert sunlight into electricity Thin wafers or films Thin wafers or films No pollution No pollution Minimal maintenance Minimal maintenance

Photovoltaic (PV) Solar Cells Can be used in remote areas Can be used in remote areas Good choice for developing countries: why? Good choice for developing countries: why? School, home use School, home use

Photovoltaic (PV) Solar Cells Can look like conventional roofing Can look like conventional roofing Prices are coming down Prices are coming down Future progress is critical Future progress is critical

Solar Thermal Electric Generation Sun’s energy concentrated by mirrors, lenses Sun’s energy concentrated by mirrors, lenses Heat a working fluid Heat a working fluid Fluid is circulated to boil water Fluid is circulated to boil water Steam generates electricity Steam generates electricity

Solar Thermal Electric Generation Backup system needed Backup system needed Very efficient Very efficient No pollution produced No pollution produced Must be cost- competitive Must be cost- competitive

Hydrogen As A Fuel Source Could be the fuel of the future Could be the fuel of the future Where does the hydrogen come from? Where does the hydrogen come from? Electrolysis Electrolysis Must use renewable fuel source to obtain the hydrogen! Must use renewable fuel source to obtain the hydrogen! Few pollutants produced when burned Few pollutants produced when burned Can be used for transportation Can be used for transportation

Biomass Energy Wood, plants, animal wastes Wood, plants, animal wastes Half of human population relies on for Cooking, heating Half of human population relies on for Cooking, heating Pros Pros Potentially renewable: why? Potentially renewable: why? Cons Cons Burned to release energy & pollutants Burned to release energy & pollutants

Biogas Mixture of gases Mixture of gases Similar to natural gas Similar to natural gas Animal wastes Animal wastes Biogas digesters Biogas digesters Decompose wastes Decompose wastes Use gas for cooking, lighting Use gas for cooking, lighting Solid remains are fertilizer Solid remains are fertilizer Can also be used to power fuel cells Can also be used to power fuel cells

Biogas Digester

Biomass As A Liquid Fuel Methanol, ethanol Methanol, ethanol Gasohol: mix gasoline and ethanol Gasohol: mix gasoline and ethanol Biodiesel Biodiesel Plant, animal oils Plant, animal oils Becoming more popular Becoming more popular Burns cleaner than regular diesel Burns cleaner than regular diesel

Ethanol Sugarcane, corn, wood, agricultural and municipal wastes Sugarcane, corn, wood, agricultural and municipal wastes Government subsidizes Government subsidizes Good outlet for some wastes Good outlet for some wastes Problems Problems Land and water use Land and water use Soil erosion Soil erosion Decreased food production Decreased food production

Wind Energy Need steady winds Need steady winds Fastest growing energy source Fastest growing energy source Pro: Pro: No waste, emissions No waste, emissions Costs are declining Costs are declining Denmark is a world leader Denmark is a world leader Great Plains of U.S. Great Plains of U.S.

Wind Power Is On The Rise!

Wind Energy Problems Birds and bats killed by turbines Birds and bats killed by turbines Avoid migration routes Avoid migration routes Operate only at certain times Operate only at certain times Monitor the project Monitor the project Visual pollution Visual pollution Maple Ridge, NY Maple Ridge, NY Massachusetts coast Massachusetts coast

Hydropower Flowing or falling water spins turbines Flowing or falling water spins turbines Most efficient way to produce electricity Most efficient way to produce electricity 19% world’s electricity 19% world’s electricity 2200 U.S. plants 2200 U.S. plants

Hydropower Problems Damages ecosystem, species Damages ecosystem, species Displaces people: Three Gorges Dam Displaces people: Three Gorges Dam High construction cost High construction cost Reduces downstream flow Reduces downstream flow Reservoirs eventually fill in Reservoirs eventually fill in Danger of collapse Danger of collapse Degrades river Degrades river Increase in waterborne disease: schistosomiasis Increase in waterborne disease: schistosomiasis

Geothermal Energy Use energy from Earth’s interior Use energy from Earth’s interior Pro Pro Big potential source Big potential source Hydrothermal reservoir: hot fluid Hydrothermal reservoir: hot fluid Bring fluid to surface to generate electricity Bring fluid to surface to generate electricity

Geothermal Energy

Cons: Cons: Not located everywhere Not located everywhere Could run out… Could run out…

Tidal Energy Use power of the tides to generate electricity Use power of the tides to generate electricity Pros: Pros: No pollution, free No pollution, free France, Russia, China, Canada France, Russia, China, Canada Cons: Cons: Very few ideal locations Very few ideal locations May be damaging to ecosystems May be damaging to ecosystems

Nuclear energy – Splits apart heavy atoms such as Uranium to release energy. Pros: - Produces large amounts of power -Very little air or water pollution -Very little air or water pollution Cons: - Radioactive waste is produced Cons: - Radioactive waste is produced -Possibility of radioactive meltdown. -Possibility of radioactive meltdown.

Conservation & Efficiency Energy conservation Energy conservation Using less energy Using less energy Reduce use, waste Reduce use, waste Carpooling Carpooling Energy efficiency Energy efficiency Using less energy for a task Using less energy for a task More fuel-efficient cars More fuel-efficient cars Both very important! Both very important!

Energy Consumption Trends Use is on the increase Use is on the increase Greatest increase in developing countries: why? Greatest increase in developing countries: why?

Energy-Efficient Technologies Appliances, automobiles, light bulbs, furnaces, etc… Appliances, automobiles, light bulbs, furnaces, etc… “Superinsulated” buildings “Superinsulated” buildings May cost more, but will save money! May cost more, but will save money!

Energy-Efficient Technologies National Appliance Energy Conservation Act National Appliance Energy Conservation Act Sets national standards Sets national standards Much greater efficiency today Much greater efficiency today Invest in energy improvements now to save money in the long run Invest in energy improvements now to save money in the long run

Automobile Efficiency Has improved since 1970s: why? Has improved since 1970s: why? Increased use of minivans, trucks, SUVs Increased use of minivans, trucks, SUVs Efficiency must continue to improve Efficiency must continue to improve

Electric Companies & Energy Efficiency Make more money, generate less electricity Make more money, generate less electricity Incentives for conservation Incentives for conservation Help consumers save electricity Help consumers save electricity Light bulbs, furnaces Light bulbs, furnaces Company doesn’t have to invest in new power generation Company doesn’t have to invest in new power generation

Electric Companies & Energy Efficiency Use cogeneration to save energy Use cogeneration to save energy Improve electricity grids Improve electricity grids Some energy lost in transmission Some energy lost in transmission Plan for future use Plan for future use

Energy Conservation At Home Average household: $1500/year on utilities Average household: $1500/year on utilities Use energy-efficient technologies Use energy-efficient technologies Better insulation, windows Better insulation, windows Seal cracks Seal cracks Replace inefficient appliances Replace inefficient appliances

Energy Conservation At Home

Case Study: Green Architecture Consider the environment when building Consider the environment when building Energy conservation Energy conservation Indoor air quality Indoor air quality Water conservation Water conservation Building materials Building materials

Case Study: Green Architecture Adam Joseph Lewis Center for Environmental Studies, Oberlin College Adam Joseph Lewis Center for Environmental Studies, Oberlin College Geothermal heat pump Geothermal heat pump PV cells for electricity PV cells for electricity Triple-paned windows Triple-paned windows Motion sensors Motion sensors Recycle wastewater Recycle wastewater Sustainable wood Sustainable wood Recycled carpet Recycled carpet