Nikki Casali Spaketh Thusly:

It'd nice to harvest it through some fibreoptic contraption brought
through the roof. I don't think it would have the same heat problems
associated with direct sunlight at the window ledge.
Velux makes a "Sun Tunnel" that does that without fiberoptics. It's on their
USA web site, but I didn't see it on their UK site.

--
Bill H. [my "reply to" address is real]
www.necka.net
Molon Labe!