I know that this is a simple looking picture, but it gives you an idea of what the superstructure supporting the dish engine system might look like. I had a much better drawing just prior to the end of my CAD class, but I have not fully mastered Autocad or Microstation and the good pictures got wiped out somehow due to my ignorance just prior to my final. Obviously I need to know how much the whole dish system is going to weigh before I can determine acceptable loads on the frame. When I have some spare time I'll come back to the drawing later. I had at the beginning a real neat solar study animation out of Microstation that showed the shadows moving, but I never got it to the point where the dishes tracked the sun. Anyway this part is only aesthetics at this point, and the real work that I am pursuing is the design of the dish, reflector, receiver and power plant.

    My preliminary idea was to drive a steam turbine directly, but since the current consensus around here is that the stirling cycle is more efficient, I will certainly be investigating that avenue as a priority.

    I don't know yet what the city planners and engineers will say when I finally submit plans to them and request a permit to build...

    Basically this structure will support two articulating 60ft diameter dishes, sitting atop of turbines or stirling engines. Most dish systems hang the stirling engine out in front of the dish directly at the focal point. That adds a lot of extra weight and supporting structure, so if the stirling cycle proves to be the best choice, I will make every attempt to try and find a way to pipe the heat down from the receiver to the engine below the dish. Assuming that a 40% efficiency can be realized, each 60ft dish collects 262kW of solar energy. 40% of that would result to 105kW of usable electric power. With two dish systems a total of 200kW should be available as long as the sun is shining, and around here lately, that has been most of the time.

    This house has a 100-Amp service main at 240-Volts Single Phase. We can turn everything on in the house and not even come close to saturation. So a 200kW system will provide more than ample power. Unfortunately, here in the state of California, the law only allows for 10kW of power per household to be fully refunded at consumer rates for the power that is returned back onto the grid. But even still, we should be generating some income, and be eliminating a significant monthly expense.

    I envision a pyramidal type structure that will sit atop of the square frames which are securely fastened to a vertical pole that is allowed to rotate freely on the Z-axis driven by a servo motor. A U shaped yoke is fastened to the top of the vertical  shaft, and the dish, receiver and engine system is suspended near the center of gravity for rotation about the X-axis. This means that the center of the dish needs to be 30 feet above highest point on the roof top. I haven't decided on the vertical up / down drive system, but any combination of hydraulics, gears or screws should do the trick.

    Aside from the thermal stresses that have to be dealt with, we often get 100mph winds called Santa Ana's coming down off of the mountains through the Cajon Pass. It is going to be real interesting to find out what kind of a sail a 60ft dish can turn into! I have heard of dishes flying off of the supports during high winds in the desert only 2 days after installation. I need to make sure that that doesn't ever happen here.