Gulf production is about 13% of US NG, from rigs and wells located offshore from about Mobile to Corpus Christi. You can get Henry Hub spot from almost any Fin site like Bloomberg.

This might help with the Nuc calculation: Source Energy: All the energy used in delivering energy to a site, including power generation and transmission and distribution losses, to perform a specific function, such as space conditioning, lighting or water heating. Approximately three watts (or 10.239 British thermal units) of energy is consumed to deliver one watt of usable electricity.

Cheers, CJ