## CSC 190 Assignment: Energy Issues

You will be assigned one of the following problems. Research the issues and make defensible estimates of the requested values using the most directly measurable quantities you can find. Use multiple sources as a check on reliability remembering that averaging widely varying values is not a particulary good method of combining conflicting information. Common sources of conflicting values include

• Numbers that do not actually refer to the same quantity,
• Transcription errors,
• Misunderstandings by amateur authors on the internet,
• True lack of information,
• Optimistic bias by interested parties,
• Deliberate attempts to mislead (i.e. outright lies).

Write up your results, approach, and information sources, and prepare to present them to the class.
On this project you are to work independently.

• How much recoverable fossil fuel (coal, oil, natural gas) is estimated to exist on the planet? How much energy would be produced by burning all of it? What fraction of the total atmospheric oxygen would be consumed in the process? If the entire population of earth used energy at the same per-capita rate as the United States, how long would this supply last? (If all the energy came from burning e.g. coal, how long would the coal last, how long would the oil last, etc.
• How much recoverable uranium is estimated to be available on earth? If this uranium were used in a conventional reactor (which mainly consumes the U235 component), how much energy could be generated? How much energy could be generated if the uranium were used in a fast breeder system instead? How long would this supply last if the entire world population consumed energy at US per-capita rates?
• How much energy could be accumulated (per unit area per unit time) using photosythesis - i.e. growing trees or other plants as fast as possible, and harvesting the (dried) biomass to burn as fuel. What percentage of the earth's surface would need to be devoted to energy agriculture to supply the world's energy needs if its population consumed energy at US rates? How much of the earth's surface is potentially areable land?
• How much energy can be generated from wind (time average per unit area) in decent wind regions (like Rochester, or the state of Iowa or Nebraska)? How much surface area would need to be populated with windmills to generate enough energy to supply word needs if everyone consumed energy like the US? What does wind energy cost (e.g. per installed megawatt capacity)? What would be the cost of enough windmills to supply US electrical needs (averaged)? How does this compare to the US GDP?
• How much solar electrical energy (e.g. per meter or hectare per year) can be practically recovered with current technology (phovoltaic or other methods) in a climate like Rochester? How about Arizona? Remember that the sun does not shine all the time, and it is not always directly overhead. How much surface area would have to be covered with solar collectors to supply the world's needs if the whole population consumed energy at US rates?
What would be the capital cost of building enough solar-electric capacity to supply current US electric needs (averaged)? How does the amount compare to the US Gross Domestic Product (GDP)?
• Extra Credit (everyone). The sun does not shine at night, and also some days, nor does the wind blow all the time. What options are available for storing solar- or wind-generated power for times on the order of 24 hours? What would be the capital cost of various technologies\ to store an amount of energy equivalent to 1 day's electrical needs for the US?