# ECE356_HW_1_2011 by prakashmoney

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```									                ECE 356 – Electric Power Processing for Alternative Energy Systems – Fall 2011

Due Date: Tues., Sept. 13                                           Name: __________________________

Required Homework 1
Electrical Energy and Power

Note: Please fill in the answers on these sheets to simplify grading but attach separate sheets, as
necessary, that include all calculations used to complete your homework so that the grader can
assign partial credit when appropriate. As an aspiring engineer, you are expected to consult the
appropriate sources (e.g., the web) to find data and other information that are not provided.

1. If all of the energy used in the US in one year were extracted from oil, what volume of oil would be
required? If all of this oil were stored in a cubic storage tank, what would be the length of one side
of the cube? Compute the corresponding volume and cube side length that correspond to the amount
of oil that is pumped annually in the US today. By what multiple would today’s US oil production
have to be boosted in order to supply the country’s entire energy requirements?

To Meet US Annual Energy Requirements:

Oil volume = __________________________ barrels = ________________________ m3

Cubic storage tank side length = ____________________ km = ______________________ miles

Current US Oil Production:

Oil volume = __________________________ barrels = ________________________ m3

Cubic storage tank side length = ____________________ km = ______________________ miles

To meet the entire energy requirements of the US:

Required oil production = _____________ x Current US oil production

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ECE 356 – Electric Power Processing for Alternative Energy Systems – Fall 2011

2. There is growing interest in plug-in hybrid-electric vehicles (PHEVs) that can drive considerable
distances in all-electric mode without using their internal combustion engines (ICEs). Consider a
hypothetical PHEV that achieves a fuel economy of 50 miles-per-gallon when using only its ICE,
and assume that only 15% of the fuel’s energy content is actually used for propulsion (the rest is
wasted as heat). In order to achieve a driving range of 40 miles, what would be the required volume
and weight of the battery energy storage to achieve this range using advanced lead-acid batteries?
Nickel-metal-hydride (NMH) batteries? Lithium-Polymer batteries? Assume that 65% of the stored
energy in the batteries is actually used for propulsion. What is the equivalent amount of gasoline
found at: http://www.madkatz.com/ev/batteryTechnologyComparison.html and use the “Lithium-
Polymer (3M)” data.

To achieve a 40 mile driving range:

NMH batteries: Mass = ________________ kg Volume = ________________ liters

Lithium-Polymer batteries: Mass = ________________ kg Volume = ________________ liters

Gasoline: Mass = ________________ kg Volume = ________________ liters

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ECE 356 – Electric Power Processing for Alternative Energy Systems – Fall 2011

3. One of the world’s largest photovoltaic (PV) solar installation is being planned for construction in
California with a total capacity of 800 MW. It actually consists of two installations. The larger of
the two will be built by Optisolar, with a capacity of 550 MW delivered by thin-film PV cells
covering approx. 3500 acres of land. How much area would be required to use PV power alone to
increase the penetration of renewable energy for the US electrical energy production from 11%
today (including hydropower) to 50% based on 2009 data? To carry out this calculation, assume
(hypothetically) that: 1) the PV arrays are capable of operating for only 10 hours per day at full
capacity (i.e., no energy production for 14 hours per day); and 2) energy storage is conveniently
available with 90% charge/discharge efficiency (i.e., 10% of the energy is lost in the process of
storing and then using it). Calculate the total area required, and, assuming a square land area, the
length of one side of this rather large PV array. If this array were installed in the state of Arizona,
what percentage of the state’s total land area would be covered by this array?

To deliver sufficient energy to increase renewable energy penetration level from 11% to 50% of US
electricity production:

Required additional PV Array Land Area = _______________________ Acres

Length of One Side of Square PV Array Area = ________________ km = _________________ mi

Percentage of Arizona’s land area required for array = _____________ %

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