1
ME 417
Design of Alternative Energy Systems
Ocean Energy Problem Solutions
1. It is proposed to build an OTEC system on Lake Superior where the summer
time surface temperature is 64
°
F and the deep water temperature is 6
°
C.
Determine the minimum amount of surface water that must be used if this
system is produce 800 kW for an allowable water temperature change of 5
°
C.
Solution:
We begin by converting our temperatures to K.
T
H
= (64+460)/1.8 = 291 K
T
L
= 5+273 = 278 K
Our Carnot cycle efficiency is then given by
0.0447
291
278

1
T
T
1
H
L
max
=
=

=
η
Our minimum flow rate of surface water required is
kg/s
852.7
)
5
)(
2
.
4
)(
0447
.
0
(
800
)
T
(
c
W
m
H
H
,
p
max
OTEC
H
=
=
Δ
η
=
°
°
2. A current energy power system is proposed for a location where the average
current speed is 0.75 m/s. Two marine turbines power are being considered for
the system, which have the following conditions
Turbine
Efficiency
Rotor Diameter
Capital Cost
Rhino
35%
45 m
$15M
Bruin
31%
52 m
$12.5M
Determine the energy cost ($/kWh) for each turbine and make an
implementation recommendation. You may take an interest rate of 13% and a
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '07
 SOMERTON
 Thermodynamics, Frequency, Heat engine, Alternative Energy Systems

Click to edit the document details