3 ms·

I've just recently learned about parabolic reflectors concentrating solar energy on water pipes: https://en.m.wikipedia.org/wiki/Parabolic_trough https://en.m.w

• kragen 8y ago
  Using non-imaging optics, trough concentrators up to a factor of five or ten suns can work through a substantial part of the day with only seasonal tracking (i.e. twice a year you go out and change their angle by hand). The very first solar power plant, in Egypt in I think about 1910, was actually a steam plant that worked on precisely this principle. Photovoltaic is cheaper in most of the world than a steam engine now, though.