Each year due to growing population and energy demands, the US faces increasing dependency on conventional fossil fuels

Each year due to growing population and energy demands, the US faces increasing dependency on conventional fossil fuels. However, in the past few decades renewable energy has begun to expand in both residential and commercial sectors of the US.

a)    

 i. The US uses roughly 6.0 million Gigawatt-hours per year in electricity. Currently 50% of our electricity come from coal. If every 1.0 kilowatt-hours of coal burned releases 2 lbs of carbon dioxide, how much carbon dioxide is released from burning coal for electricity each year in the US?

 ii. If coal usage can be reduced by 20% by utilizing solar energy, how much carbon dioxide will be saved from entering the atmosphere each year?

b) Describe several disadvantages to using wind energy.

c) Identify and describe a type of active solar heating method.

d)  Give ONE advantage and ONE disadvantage to the 3 methods used to generate electricity described above.