Oh dear, unusual for the The Economist to be this far off the mark (IMO).
1. Crude oil vs Distillates. Yes the US still imports crude oil which it refines and exports as distillates
2. Heavy oil vs Light Tight Oil. The US is a net exporter of LTO (that which is mostly produced from the shale basins). Heavier grades of crude now mostly come from Canada
3. Yes the US is no longer dependent on OPEC oil ... but not totally independent of foreign oil imports
4. "America" does not have NOCs like China and KSA and Iran/Iraq etc etc. Independent public and private E&P companies produce US oil on a competitive open market basis.
FPL's close location to these shale basins? Its on the margin of the DJ Basin but let me just say I just recently drove across Fremont County on CO SH #50 from West to East through Canon City on my way to Denver via Colorado Springs. Now Canon City is a few miles (i.e. close) to Florence CO. Not a single O&G well to be seen. Not so for the counties surrounding Denver which is over a 100 miles north of Florence (i.e. not so close).
BTW the main industry of Canon City and Fremont county - correctional facilities (i.e. prisons).
