The reality, provided by the oft-ignored Energy Information Agency? About 3.5 percent, all told. Alaska provides 14 percent of the crude oil produced in America, but that's not 20 percent of the US domestic energy supply, and in any case Alaska supplies only 4.8 percent of the oil suppied [sic] to the US. Did she mean natural gas? Nope; Alaska produces less than 2 percent of the US' total natural gas supply. However you slice the numbers, Alaska doesn't produce anywhere close to 20 percent of the domestic US supply of energy. Palin is wrong.Hold on! Hold your horses! Wait just one sec! WOAH, WOAH, WOAH!
If you add the correct numbers together, you will indeed find that Palin was pretty close to being right. See, if you add together the percentages of the crude oil produced in the US, the oil supplied to the US, and the US total natural gas supply. If you do the math, then you get:
14% + 4.8% + 2% = 20.8%.
See? She was very close about her knowledge of energy in the US.
Unfortunately, this does mean that her units are about as consistent with each other as VenomFangX was when he did his own screwy-math.