[填空题]
Solar cells (Fig. 15–2pd6sf3: inpco r w-py+.+i5ou 6)kak* 9z2bu kqmle8 -)tvg(i3 m can produce about 40 W of electricity per square meter of surface area if directly facing the Sun. How large an area is ru23iqml emk9ga zb(kt8) k *v-equired to supply the needs of a house that requires $22k\,Wh/day$ Would this fit on the roof of an average house? (Assume the Sun shines about $9h/day$) $m^2$
