• What are the pros and cons of both renewable and nonrenewable energy?

• Is the implementation of renewable energy in modern society realistic?

• Coal as an example of nonrenewable energy; contrasting wind, hydro, nuclear as alternatives.

OverviewOverview

World Energy UseWorld Energy Use

World Energy UseWorld Energy Use

PA Energy UsePA Energy Use

• PA is the 6th largest consumer of electricity in U.S. (TX, CA, FL, OH, NY)

• PA is the 5th largest producer of electricity in U.S.

• Primary energy source is coal

PA Energy UsePA Energy Use

Coal: ProsCoal: Pros

• The only thing that keeps some countries, such as China, using coal is because it’s

• A) Cheap: about 4 cents for every kilowatt-hour of energy produced, or 3,600,000 J

• B) Efficient: when coal is burned, about 40% of its energy is converted into electricity

Coal: ConsCoal: Cons

• Coal’s combustion adds more carbon dioxide emissions to the atmosphere than any other resource

• Coal plants emit toxins such as sulfur dioxide, nitrogen oxide, carbon monoxide, hydrocarbons, and others

www.ecolo.org

Coal: Health EffectsCoal: Health Effects

• Coal mining deaths are common, especially in other countries

• The pollution from nearby factories can enters houses

Pros & ConsPros & Cons

• Pros• It’s cheap• It’s efficient• It’s domestic

• Cons• It pollutes• It releases CO2• Mining is dangerous• Strip mining destroys

the environment• It’s non-renewable

PA Energy UsePA Energy Use

Wind Power ProsWind Power Pros

• 3-4.5 cents/kilowatt-hour (kWh) – comparable to coal (?) over time

• Expensive to install, around $1M for a big 750 kW turbine

• Over time, costs may be mitigated• No water involved• Potential for new technology to improve

Wind Power issuesWind Power issues

• Wind power has about 20% conversion efficiency—only about half as much as coal power

• There are two

factors in determining

how much power you’ll

get: wind speed,

and wind consistency

www.bpa.gov

Wind Power drawbacks?Wind Power drawbacks?

• Wind farms take up a lot of space• Can dominate a landscape that might otherwise

have aesthetic value, and can be noisy: “NIMBY.”• Can kill birds or interfere with television signal• Expensive to start without capital in place• A challenge to generate power to meet demand

www.smh.com.au

Wind Power drawbacks?Wind Power drawbacks?

www.smh.com.au

Wind Power in PAWind Power in PA

• PA wind potential is 5,120 MW (22nd in US)

• 155 MW of generation already • About 99 turbines in 5 locations• Power for ~60,000 homes• 12th largest in U.S.

– Additional 200 MW proposed• About 100 turbines in about 10 locations

Hydroelectric PowerHydroelectric PowerFlowing water turns a turbine, providing the kinetic energy to generate an electrical current.

AdvantagesEconomic benefits include:

~No fuel costs~Low labor

Dams provide recreation and flood protectionDams have a long lifeproduces constant powerIt conserves fossil fuelsIt prevents pollution caused by fossil fuels

Hydroelectric PowerHydroelectric PowerFlowing water turns a turbine, providing the kinetic energy to generate an electrical current.

DisadvantagesCan have an impact on the Can have an impact on the aquatic environmentaquatic environment Construction costs are highConstruction costs are high People can be displaced when People can be displaced when artificial lakes are createdartificial lakes are created

Nuclear Energy in PANuclear Energy in PA

• 5 facilities

• 9 operating reactors, 2 are local

• 18% of PA’s nuclear generated energy is local to Pittsburgh: Beaver Valley

Nuclear Energy in PANuclear Energy in PA

http://www.eia.doe.gov/cneaf/nuclear/page/nuc_reactors/small_pwr.jpg

Beaver Valley:2 PWRs(Pure Water Reactors)

Nuclear Energy in PANuclear Energy in PA

http://www.eia.doe.gov/cneaf/nuclear/page/nuc_reactors/small_bwr.jpg

Most other PA plants:BWRs(Boiling Water Reactors)

Nuclear Energy Pro & ConNuclear Energy Pro & Con

• Low CO2• Technology exists• High capacity for

electrical generation• Reliable operations

under optimal conditions; use small amounts of fuel

• Long-lived radioactive waste products (10K yrs)

• Accidents have potential to be devastating

• Terrorism target• Fuel may be a limited

resource; physical and chemical hazards in mining and processing ore

• Long lead time to build new facilities (20-30 yrs)

An online sourceAn online source

http://www.eia.doe.gov/oiaf/ieo/ieohcon.html

• http://www.eia.doe.gov

Energy Information Administration

(Official energy statistics from the US Government)

Alternative Energy SourcesAlternative Energy Sources

• It’s not easy to quantify exactly which renewable resource is better—each has its pros and its cons

• Renewable energy may not replace fossil fuels overnight, but technological advances may close this gap in the future