23:2823:28, 25 June 2008diffhist−1
Solar energy
reordered sections to place scheffler reflector description above its mention in the process heat section
23:2723:27, 25 September 2007diffhist+25
Solar energy
Specified Bell Lab's solar cells as marking the modern age of solar cells rather than the first solar cells. Added some efficiency numbers.
23:2823:28, 25 June 2008diffhist−1
Solar energy
reordered sections to place scheffler reflector description above its mention in the process heat section
23:2723:27, 25 September 2007diffhist+25
Solar energy
Specified Bell Lab's solar cells as marking the modern age of solar cells rather than the first solar cells. Added some efficiency numbers.