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. Overview

World Energy Use

PA Energy Use PA is the 6 th largest consumer of electricity in U.S. (TX, CA, FL, OH, NY) PA is the 5 th largest producer of electricity in U.S. Primary energy source is coal

PA Energy Use

Coal: 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: 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

Coal: Health Effects Coal mining deaths are common, especially in other countries The pollution from nearby factories can enters houses

Pros & 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 Use

Wind Power Pros 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 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

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

Wind Power drawbacks?

Wind Power in PA PA wind potential is 5,120 MW (22 nd in US) 155 MW of generation already About 99 turbines in 5 locations Power for ~60,000 homes 12 th largest in U.S. –Additional 200 MW proposed About 100 turbines in about 10 locations

Hydroelectric Power Flowing water turns a turbine, providing the kinetic energy to generate an electrical current. Advantages  Economic benefits include: ~No fuel costs ~Low labor  Dams provide recreation and flood protection  Dams have a long life  produces constant power  It conserves fossil fuels  It prevents pollution caused by fossil fuels

Hydroelectric Power Flowing water turns a turbine, providing the kinetic energy to generate an electrical current. Disadvantages  Can have an impact on the aquatic environment  Construction costs are high  People can be displaced when artificial lakes are created

Nuclear 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 PA nuc_reactors/small_pwr.jpg Beaver Valley: 2 PWRs (Pure Water Reactors)

Nuclear Energy in PA nuc_reactors/small_bwr.jpg Most other PA plants: BWRs (Boiling Water Reactors)

Nuclear 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 source Energy Information Administration (Official energy statistics from the US Government)

Alternative 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