Environmental Engineering Reference
In-Depth Information
Figure 1.7 (a) Map of requirement of land to
meet the world
s total power demand (http://
ethic-forum.unife.it/E602373e_ev-Balzani.pdf.)
in mid-century solely by solar cells. (b) Map of
solar intensity across the United States. The
units are described in the text. (Reproduced
from Ref. [3], Figure 13.5, p. 159. Source U.S.
Department of Energy, Energy Efficiency and
Renewable Energy Division).
speed v of
fluid of density
r
. In one second, a length L
¼
v containing mass M
¼
Av
r
dM/dtv
2
/2,
will pass through the area. This represents a
owof kinetic energy dK/dt
¼
¼g
dM/dtv
2
/2 can be obtained if the ef
ciency of the
so that power P
¼g
dK/dt
turbine is
g
. Thus,
Þ¼gp
R
2
r
v
3
P
ð
R
=
2
:
ð
1
:
11
Þ
