The “grid” isn’t really as pressed as you think it is. Also I put grid in quotes because there’s more than one, and there are also local issues that are different from grid-wide issues.
There are three grids in the U.S., the Eastern, Western, and Texas (because Texas is, well, Texas…). The Eastern grid is fine except for the northeast part of it, which is always a bit overloaded, at least in the summer during the day. Similarly, the western grid is mostly fine except for southern California, where it is also overloaded in the summer. And Texas is usually just great unless it gets record-breaking cold weather that it wasn’t designed to handle, in which case it goes to hell in a handbasket. But loading-wise, under normal weather, it’s usually fine.
On a more local level, you may have issues though, as many have mentioned upthread. A particular substation might be overloaded or your home’s service may not be adequate. But the power grids, for the most part, aren’t the issue, except in the northeast and southwest. Every other area of the country has plenty of power to spare, generally speaking.
A few strategically placed power plants in the northeast and southwest will solve that basic problem, though this is probably also going to require significant infrastructure costs for wiring and equipment that can handle the additional loads. So basically New York and southern California are screwed, but the rest of the U.S. doesn’t need to worry about its grids.
Meh. If you need a lot of power, your choice used to be coal plants or nukes. But then people started specifically focusing on coal plants, so the coal plants have been mostly switched to natural gas instead. Your current choice is really down to natural gas and its corresponding greenhouse gas emissions that destroy the atmosphere, or nuke plants which create nuclear fuel which poisons its part of the environment for tens of thousands of years and has no really good long-term storage solution.
It would be nice if the grid could get greener, but wind and solar don’t produce enough power and aren’t consistent, hydro destroys the environment and is mostly already loaded to capacity, and other sources like biomass, geothermal, wave energy, etc. just don’t produce enough power.
As much as I would like to see green energy, I don’t see this changing significantly within my lifetime. We’re stuck with producing just enough green energy to make environmentalists feel better while realistically being forced to choose which environmentally horrible solution we want for the bulk of our power.