October 25; Lecture 2/5Physics and Society 1 Physics and Society Lecture 2 <> October 25, 2004 Richard J. Plano Today: Energy First a little physics The magnitude of the problem Solutions (?) 1.Continue? NO! 2.Coal, Oil, Gas? NO!

October 25; Lecture 2/5Physics and Society 2 Agenda ( Cont) 1.Wind? Will help. 2.Solar? A possibility (expensive). 3.Nuclear Power? Great idea! 4.Hydrogen economy? Forget it!

October 25; Lecture 2/5Physics and Society 3

October 25; Lecture 2/5Physics and Society 4 Thermodynamics (A dismal science) No Perpetual Motion Machines!!! First Law: Energy is Conserved You can’t win! Second Law: You can’t just take energy from a reservoir and produce an equivalent amount of work. You cannot break even! Third Law: Entropy (disorder) always increases. Things are getting worse!

October 25; Lecture 2/5Physics and Society 5 Clean and efficient coal burning Secretary Abraham Announces $235 Million for Florida Clean Coal Plant Project Expected to Create More Than 1,800 Jobs ORLANDO, FL -- Secretary of Energy Spencer Abraham, joined by Governor Jeb Bush, today announced a $235 million grant from the U.S. Department of Energy that will aid in the development of one of the cleanest coal-fired power plants in the world. The project is a team effort led by Southern Company. The grant comes as part of President George W. Bush’s 2002 Clean Coal Power Initiative (CCPI) to invest $2 billion over 10 years to advance technologies that can help meet the Nation's growing demand for electricity while providing a secure and low-cost energy source and protecting the environment.

October 25; Lecture 2/5Physics and Society 6 The Exxon Valdez in trouble

October 25; Lecture 2/5Physics and Society 7 Typical yield from one barrel of crude oil Product Gallons Finished Motor Gasoline Distillate Fuel Oil 9.70 Kero-Type Jet Fuel 3.99 Residual Fuel Oil 1.76 Still Gas 1.89 Petroleum Coke 2.14 Liquefied Refinery Gas 1.76 Asphalt and Road Oil 1.34 Naptha for Feedstocks 0.63 Other Oils for Feedstocks 0.50 Lubricants 0.46 Special Naphthas 0.13 Kerosene 0.17 Miscellaneous Products 0.17 Finished Aviation Gasoline 0.04 Waxes 0.04 Total One barrel = 42 gallons

October 25; Lecture 2/5Physics and Society 8 The most efficient possible heat engine is described by the Carnot Cycle. Typically hot = 500K; cold=350K e = 30%

October 25; Lecture 2/5Physics and Society 9 Energy Usage at the Plano Household Electricity Natural Gas 24 kWh/day=>1 kW average 3.1 Th/dy = 90 kWh/day=>3.8 kW Annual: 9000 $0.12/kWh $ ,000 $0.034/kWh $1150 Gasoline: Camry + Prius 15 gal/wk = 780 $2.00/gal = $ gal => 28,000 kWh

October 25; Lecture 2/5Physics and Society 10 Numbers, Conversion Factors, etc. Energy: kWh, Joule, BTU, Hp-h Power: kW, Watt, BTU/s, Hp 1 kWh = 3.6E6 Joules = 3413 BTU = 1.3 Hp-h 1 Therm = 1E5 BTU = 29.3 kWh 1 gal gasoline => 49 Hp-h=36.6 kWh. =>8 lb = 3.6 kg => 3.6E-3 m^3 Natural Gas = 0.30 kWh/ft^3; Coal = 5860 kWh/ton H2 gas = 39 kWh/kg = 0.09 kWh/ft^3 (STP) 1 m^3 = 35.3 ft^3; 1 Barrel (bbl) = 42 gal 1 tanker carries 250,000/500,000 tons of oil (Seawise Chant is 1504ft x 226ft – 500,000 tons)

October 25; Lecture 2/5Physics and Society 11 Electricity Total USA: 3.7E12 kWh Note: 4E8 times Planos USA Pop 295,000,000 = 3E8 Gasoline 4.7E12 kWh =1.3E11gal Note: 1.7E8 times Planos Total Annual Energy Usage in the USA This is a lot of energy! One year’s supply of gasoline would fill a tank 30 ft high by 4.5 miles x 4.5 miles! Need 12 supertankers/day to supply <1/2 of petroleum.

October 25; Lecture 2/5Physics and Society 12 Population! Note that if the U.S. population were the same as when I graduated from high school in 1947 (144 M), we would NOT have to import ANY oil! U.S. population is now 295 M and growing! When I was born in 1929, US pop was 122M and world pop was 2B; in 1900 US was 76M and world was 1.6B. World now: 6.4B. Much less stress on environment…

October 25; Lecture 2/5Physics and Society 13 Capacity and Production by Fuel Note that gas, coal, and, especially, nuclear produce more relative to their capacity.

October 25; Lecture 2/5Physics and Society 14 Coal and Natural Gas One TVA plant uses 14,000 tons of coal/day = 140 railroad cars! Generates 1E10 kWh/yr; Average of 1200 MW (700,000 homes) Need 370 such plants to meet USA needs. If powered by natural gas (0.30 kWh/ft^3), need about 2.74E8 ft^3 each day. A rectangular tank to hold this much at STP would be 30 ft high by 3000 ft on a side. Both, esp. coal, generate a LOT of CO2 and other junk, leading to global warming and many forms of pollution.

October 25; Lecture 2/5Physics and Society 15 Windmills Wind has kinetic energy: Must stop the air to get all the energy; But then no air passes so m=0, so no energy. Most efficient if leaving air has 30% of its initial speed. Therefore, windmills must be spaced rather far apart. Typically 7*D in wind direction and 4*D perpendicular, D = diameter of propellers

October 25; Lecture 2/5Physics and Society 16 Windmills are BIG! To supply our electrical needs, about 4,000,000 1 MW windmills are needed! They need an area 350 miles on a side. Some dislike them as neighbors.

October 25; Lecture 2/5Physics and Society 17 Could windmills provide all our electrical needs. ??? Use 1 MW windmills; diameter of rotor is 54 m. Each needs an area: 4D x 7D = 216 m x 378 m = 0.08 km^2 = 0.03 mi^2 A 1 MW windmill generates about 0.2 MW on average, so we need: 8E5 MW/0.2 MW/windmill = 4E6 = 4,000,000 windmills. These would cover an area of at least 120,000 mi^2 => An area at least 350 miles on a side!!! They are also a danger to birds (and bats), but cell phone towers pose a much larger hazard.

October 25; Lecture 2/5Physics and Society 18 Wind Power available by state Note: 1billion kWh = 1E12 kWh We use 3.7E12 kWh of electricity each year, 3E13 kWh of all kinds of energy.

October 25; Lecture 2/5Physics and Society 19 Problem: Bats in the windmills! Unusual Alliance Hopes to Keep Bats out of Wind Turbines 4 March Conservationists, industry officials and federal agencies are joining forces to address an unexpected side effect of renewable wind energy. Bats in some parts of the country show an unexplained tendency to collide with the blades of wind turbines. AWEA News ReleaseAWEA News Release