Here's an Ars Technica write up of a study like that, if it's not the one the original poster had in mind:

> A new study released Monday looks into what would happen if that limitation were eliminated. It envisions a massive web of high-voltage, direct-current transmission lines, hooked up to 32 nodes spread across the US. This allows a massive spread of renewable power that could be dispatched anywhere in the nation. The result is a grid with dramatically lower carbon emissions and the bonus of lower costs to consumers.

https://arstechnica.com/science/2016/01/making-a-single-us-e...

Of course it's one thing to engineer a carbon- and cost-minimal grid in theory, it's another thing to try to construct a market that could reach that optimum, or get it enacted politically.

This HVDC network is something I think of every few months, not only for the idea itself, but for the futility of a really really good idea that has every bit of politics stacked against it.

Haven’t read it yet, but this looks like it might be it:

https://www.nature.com/articles/nclimate2921

The WSJ article is an excerpt from a coming book, so I’d imagine the study will be listed in the footnotes.

PDF link: http://www.tresamigasllc.com/docs/nclimate2921.pdf