Posted by Lee on April 15, 2007, 10:36 am
See this table
It compares different types of collectors. I was very interested
the figures especially Flat Plate (21%) vs Parabolic Trough (56%).
I'm not really sure I understand Carnot efficiency. Let's say we
to heat water to 60 degrees C. Is this table saying that a trough
be more than twice as efficient?
Posted by DJ on April 16, 2007, 1:03 am
Yes, pretty much. What it's NOT saying clearly (it does say it's a
single axis tracker), however, is that the trough needs to be
motorized and have a solar alignment tracking system so that it can
continuously follow the sun's path across the sky to achieve these
numbers, whereas a flat plate collector "just lays there".
This does add substantially to the cost of a trough collector.