Land footprint of solar energy:
(a) In 2016, Arizona’s total annual electricityconsumption was 78.05 million MWh. What is this in terms of kWh perday?
(b) Land footprint: The average dailyinsolation in Phoenix is 5.38 kWh/m2/day. Given this daily energyinput, how much land area would you need (in square miles) togenerate all of Arizona’s daily electricity from the followingtypes of PV panels:
i. Mono-crystalline Si panels with an efficiency of 22 %?
ii. Thin film CdTe with an efficiency of 12%?
(c) Translate to rooftops: Assuming we use 22%efficient mono-crystalline Si panels, how many rooftops would thattake if we put the panels on:
i. Wal-Mart stores with an average size of 102,000 squarefeet?
ii. Household rooftops with an average size of 2,000 squarefeet?
(d) Reflection: These types of crude statisticsget used all the time in public debates about solar energy. Do youthink they’re useful? Why or why not? Take about 3-4 sentences toexplain what we learn from this exercise and whether you think it’suseful for talking about solar energy.
