When I was living in Miami years ago there was a solar ORC company I actually talked to the owner. I cant find it today. the system used refrigerant as the working fluid and was a sealed system. It used a rotary valve and there was confusion on the valve gear as in the machinist wanted to patent the valve gear.
A lot of these company's boast about solar power. The guy with the ORC I was talking with, used a high volume condenser of some sort.
I think that's problem with a ORC you have to trade area for condensing thus pulling energy from the environment.
I discovered that you could absorb the heat in air when I was running engines from high pressure (2400psi) C25 the engines got very cold but since it was a 4 cycle, there was heat of compression so the engine did not ice over. Also worth noting is that the flywheel acts as a fan and flows air over the cooling fins, this made a huge difference in performance.
