alt.energy.homepower

-> But in the summer solstice, because the pole is tilted toward the sun, when
-> you have the sun again to the right you would see that the trough is
-> perpendicular to the pole axis and thus would *not* be perpendicular to the
-> day-night perimeter. As the planet rotated on this day, the plane of the
-> trough would sweep out a conic shape and only at noon would it intersect the
-> sun.

-> For the proper theoretical aim of the trough, it would need a tracker
-> mechanism that 1) aimed the end of the trough to the point on the horizon
-> where the sun would rise, 2) slowly turn throughout the morning so it was
-> oriented exactly east-west at local solar noon and 3)continue turning as the
-> sun traces across the sky such that the opposite end of the trough ends up
-> pointing exactly where the sun sets everyday.

-> On the equinoxes this would be zero amount of rotation throughout the day.
-> In the summer it would start 'facing' southeast with the east end pointing
-> in the northeast and twist 'clockwise' throughout the day and end up
-> 'facing' southwest with the west end pointing to the northwest. Curiously,
-> in the winter it would start 'facing' southwest with the east end pointing
-> to the southeast and twist 'counter-clockwise' throughout the day and end up
-> 'facing' southeast with the west end pointing southwest. Quite a tracker
-> (unless you just use a computer to figure out the motion every day).

-> Tracking a long narrow trough is probably harder than a square-ish flat
-> plate collector too.

-> daestrom
-> . That's not to say a simple east-west orientation is useless, far from
-> it. But it isn't 'optimal'.

Yes. Obviously, like me, you can visualize things in three dimensions
and "watch" them move "in your mind's eye". I have tried to explain
this to people who prefer two dimensions and to sketch things on paper.
They have a horrible time trying to understand it!

I agree that to make a horizontal trough properly focus sunlight
throughout the day would require it to move in a complicated way. The
system would lose its basic simplicity, which is the east-west trough's
most attractive feature. If we're going to use computer control and the
like, we might as well make a proper sun-tracker, which moves in two
dimensions to point directly at the sun. That would be my choice,
anyway.

dow