It's possible, but solar thermal has proven to be less efficient than photovoltaic at capturing energy from the sun. The only advantage is that you can coast on stored heat after the sun sets to keep making energy. Other than some pilot plants solar thermal is going nowhere.
Condensing the steam down and trying to extract energy from the condensation flowing downhill is orders of magnitude away from being worth it. The sun is boiling a few gallons of water per minute at best, while hydroelectric systems are measured millions of gallons per minute.
However, what you have described is similar to the basic design of closed-loop industrial solar thermal systems: they concentrate solar power to heat a liquid or other medium and use the heat (or heat differential) conventionally (see, for example the Ivanpah Solar Power Facility near Las Vegas).