The oldest wind farm in Pennsylvania is Humboldt Industrial Park, in Luzerne County, which went online December 31, 1999. The two 65-kilowatt wind turbines were predicted to generate 200,000 kilowatt-hours of wind energy each year, replacing conventional electric generation that would otherwise annually produce 140 tons of carbon dioxide-the primary source of global climate change. Wind energy from these first two turbines also avoids the annual production of 800 pounds of nitrogen oxides and 1,900 pounds of sulfur dioxide. The local community in Luzerne County had mixed reactions to the news that another wind farm was being installed in 2005. Some were excited about the possibility of lower energy bills, some were concerned about the effects on the environment, and others wondered if there was enough local wind (average wind speed = 10 miles per hour) to make such an investment worthwhile. An average wind speed of 9 to 13 mph is sufficient for most sizes of wind turbines. The power available in the wind is proportional to the cube of its speed, which means that doubling the wind speed increases the available power by a factor of eight.
A) If the wind speed averages 11 mph on Ashley Hill and 12 mph on Genevie Hill, then a turbine operating on Genevie Hill could, in theory, generate about % more electricity than a turbine on Ashley Hill.
a. 1
b. 10
c. 20
d. 30
e. 50
B) An average household uses about 10,000 kilowatt-hours of electricity annually. The first two turbines installed at Humboldt Industrial Park provide enough electricity to completely provide for the needs of approximately how many households?
a. 20
b. 200
c. 2,000
d. 20,000
e. 200,000
C) An average household uses about 10,000 kilowatt-hours of electricity annually. How many tons of carbon dioxide would be produced if the household's electricity were generated using only conventional energy sources?
a. 2,800,000
b. 1,400,000
c. 700
d. 70
e. 7
D) The production and consumption of electricity are most commonly measured in kilowatt-hours (kWh). A kilowatt-hour is one kilowatt (1,000 watts) of electricity produced or consumed for one hour. A 10-KW wind turbine can generate about 10,000 kWh annually (enough to power a typical household) at a site such as Spirit Lake, Iowa, with wind speeds averaging 12 miles per hour. The 250-kW turbine installed at the elementary school in Spirit Lake provides about _of electricity annually.
a. 250 kWh
b. 250 mWh
c. 2,500 kWh
d. 25,000 kWh
e. 250,000 kWh