US spacecraft have had solar energy before. Skylab, the ISS, a lot of unmanned satellites.
Frankly, the whole way we approach our space program needs an overhaul.
If it were me, I'd have a tiered system. Make your man rated system a small reusable item, like a spaceplane. It doesn't (and shouldn't) be a big large spacecraft...the idea is to get people up and down safely...maybe small reconnaissance type missions, but that's it. The idea is not to send up something the size and weight of a DC-9 everytime you launch a human.
Then, have a family of dumb, simple boosters (aka Big Dumb Boosters) for your freight hauling needs. Simple, robust, cheap. Hell, Apollo 12 was struck by lightning during ascent, but kept on going...that's the kind of rockets we could use for our freight hauling. You could even make the first, biggest stages recoverable if you want.
FC