Found this
site, an entry in an backyard turbine builder's club.
The premise: Solar photovoltaics are still too expensive an investment for most, given their relatively high cost per watt. Why not build small thermal solar arrays to drive closed-loop steam turbines connected to generators?
Whether or not the wife would approve such a contraption in my own backyard is quite another matter. It would take up all the space for the new porch. . . .