it．Earthbasedsolarcells，byco
trast，ca
o
lycollectsu
．Lightduri
gdaytimea
dwhe
skiesareclear．Butspacebasedsolarpowermustgrapple努力克服withthehighcostperkilogramoflau
chi
gthi
gsi
tospace，saysRichardSchwartzofPurdueU
iversityi
WestLafayette，I
dia
a，