For those interested, here's the simple math:

100 miles x 100 miles = 10,000 square miles

1 mile = 5280 ft

10,000 square mile = 5,280 x 5,280 sq ft = 27,878,400 sq ft

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One of the posters above has a 240W solar panel, probably like this one:

[link to www.gogreensolar.com (secure)]

so, he gets:

240 W / (65in x 39in) = 240 W / 2,535 sq in. = 240W / 17.6 sq. ft
240 W / 17.6 sq. ft = 13.6 W/sq. ft.

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The total max power that can be generated from 10,000 square miles of these panels is:

13.6W/sq.ft x 27,848,400 sq. ft. = 379,661,027 W ~= 380 MW

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The total energy produced from this many panels over 24hrs is:

380MW x 24hrs = 9,112 MWhrs = 9.1 GWhrs

and the total over 1 year is:

9.1GWhrs x 365 days/yr = 3326 GWhrs

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How much electricity is used in the US annually?

[link to www.eia.gov (secure)]

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So, a 10,000 sq mile solar farm with this model solar panel can supply:

3326 GWhrs / 10.4MWhrs per household = 319, 791 households

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How many households are in the US?

[link to www.statista.com (secure)]

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So, the OP's proposed solar farm can power at best:

319,791 / 127,590,000 = 0.25% of US households

Sorry, fail, interesting calculation though.