The question of going to a predominantly electric train system in the U.S. is not is it possible, it's whether it is economically feasible? In this video clip from "The High Energy Show" on Motley Fool Live, recorded on April 5, Fool.com contributor Lou Whiteman discusses the mammoth costs involved to set up an electrified rail infrastructure in the country.

Lou Whiteman: This is electrification coming everywhere, and there's a weird line between, is it possible and is it feasible here with what we're going to talk about. Because what we're dealing with, with a lot of today's battery technology, is a paradox that is hard to solve.

Batteries right now are very heavy. The more thrust you require to either move very heavy trains or to get a plane airborne, the more batteries you need adding those batteries creates a need for more thrust, which therefore creates a need for more batteries, etc., which has been a real bugaboo here and it is why we don't have more electronics. We'll talk about some of the ways it isn't a nonstarter. It's just really hard to do.

Trains, I think are the most obvious one because trains in theory, even more so than cars, we know exactly where they're going. Europe has had some success electrifying its rail basically by putting in wires. You can't do that with airplanes so much, as much as we joked about it. But you can put wires over train tracks.

Unfortunately, that's an easy engineering problem to solve. It's a heck of a cost. We're not just talking about adding the wires everywhere. We're talking about 100 years of infrastructure that isn't set up for wires. Think about how many road bridges go over train tracks.

Think about, especially on the East Coast, you have 120-year-old B&O tunnels going under Baltimore, Maryland. They're not big enough right now to get the latest and greatest train cars through them. The idea of adding just five or six feet to add wires, over 140,000 miles of train track is just a massive cost.

Caltrain and I know it's California, so everything's more expensive. Caltrain electrified 50 miles, it costs them $2 billion dollars. That's $40 million per mile. You apply that to the U.S. rail network, 140,000 miles, that's $5.6 trillion with a "T."

It's California, that's probably a terrible comparison. But say in the rest of the country, it costs 10% of that, that is a $560 billion spend to electrify rail. Quite frankly, that's just not going to happen even if it is feasible.