Because with a heliostat you have to move the energy as heat and that isn't as efficient and definitely not as easy or cheap as moving it as electricity. Do th

Because with a heliostat you have to move the energy as heat and that isn't as efficient and definitely not as easy or cheap as moving it as electricity. Do the numbers. Making the top of the heliostat isn't what matters. What matters is making the inside of a pile of dirt that hot.