This framing is wrong, presents a false choice, and is indefensible when looking at global emissions.
The choice isn't onsite generation OR transmission/central generation. Both can and are happening together. And they need to.
And "onsite" and "off-grid" are not the synonyms. A facility can use onsite gas while connected to the electric grid. In fact, doing both makes the grid more flexible.
The REAL issue is the counterfactual: Does onsite generation allow that new semiconductor fab, battery plant, solar manufacturer, or data center to get built in the United States years sooner than it would otherwise.
The answer is yes. And if that's the case, the comparison on emissions can't stop at the emissions rate of onsite gas versus the average U.S. grid. Becuase the alternative is delayed or foregone U.S. investment, or investment in or shifting compute to another country.
China is still generating 55% of it's electricity from coal. IEA says that 70% of Chinese data center energy currently comes from coal, and that coal will be the largest source of energy for new data centers in China.
The U.S. is in the midst of an extradinary build-out of manufacturing, including solar, batteries, semiconductors, data centers, and so much more.
So let's build the onsite gas *and* transmission. Build new gas, nuclear, solar, wind, batteries. Build the new pipelines and gas storage.
But let's not treat onsite gas as the enemy of grid expansion. Indeed, onsite gas is going to facilitate it, not limit.
The relevant emissions question isn't simply “How many tons does this gas unit emit?” The right question is “What happens to investment, production and global emissions if we prevent or delay this U.S. project?”
That's the right frame, and one that actually matters for emissions.
So let's get to building.
People need to understand that the biggest threat to emissions right now is off grid, inefficient gas. Beyond the tremendous general emissions upside of transmission buildout, if it means more grid-connected gas that is anywhere from like 20-70% fewer emissions than status quo.