Constructing an EMP-proof power grid

I'm not sure anyone notices this, but a lot of my posts have hyperlinks to necessary sources imbedded. If you see something in odd print, try clicking on it.

Many sources, from NASA to USA Today, are warning of the rising dangers from a coming Solar Maximum and a possible EMP storm that could knock out transmission lines from coast to coast. Our current electric grid is based on traditional ohm-resistance power lines (essentially anything made of metal that doesn't have to be frozen) that, when exposed to too high of a current, burn out. Not only does this make them susceptible to solar flares, but it also causes massive losses of electricity through transmission, and requires elaborate mechanical tinkery to prevent more down-to-earth dangers (such as lightning bolts) from threatening the grid too often, and causes blackouts that cost billions of dollars to repair.

I believe I know of a way to, for possibly less than the costs already attributable to these other phenomena, harden our existing power grid against Electromagnetic Pulse. Superconductors have the disadvantage that they must be kept cold, the world record for superconductivity is 5 degrees Fahrenheit, but if used in the place of existing power lines for long transmission systems (ie. LA to Las Vegas) would both eliminate the danger of EMP to transmission lines (along with lightning bolts and any other overload danger), move the limit of capacity to infinity, and eliminate losses from transmission. There would be power losses attempting to keep these lines cold, but refrigeration to 5 degrees Fahrenheit (a temperature you might encounter on a winters day in NYC) is something we have done for a long, long time, and is a very ready and understood technology that could be adapted in many ways by the engineering staff. My suspicion is that overall there would be a net gain in power transmission. The refrigerator would have to be built in a way so that it too is thunderproof, but that can probably be done.

In addition to hardening transmission lines, we will need to also "harden" (or something similar) crucial computer systems. Here the best thing to do might be to keep a single central mainframe underground, and use well grounded telegraph lines to communicate with systems at a facility (such as a nuclear power plant) that needs this kind of utility, much like the lines used to carry messages in the Old West. This might cost a bit more, so you might not want to do it that often.

With the exception of the superconductor, the rest of this is very down-to-earth, relatively inexpensive and well-understood technologies. The superconductor has a specific chemical formula ((Tl₄Ba)Ba₂Mg₂Cu₇O₁₃₊), and is a pure material, so finding a process to make it efficiently should be practical.