A photovoltaic installation will be built in a village, town or city of your choice in England. Its flat active surface will be tilted from horizontal and pointed 100 west of due south. After clearly starting the name of the village/town/city and its exact latitude calculate the following at 15:00 on May 15:
a) The declination angle
b) The solar altitude, noting that in the horizontal plane angle β is zero
c) The azimuth angle
d) Sunrise and sunset times, and the day length
e) The air mass and total solar irradiance
A lighting system, powered by a nominally 24V battery, will be charged by the photovoltaic installation. In May the lighting will be used for 4h each night, drawing a current of 9A. Given the battery requires 20% more than its nominal voltage for charging, and has a 90% charge/discharge round-trip efficiency, calculate:
f) Charging voltage and minimum daily charge (in Coulombs) required by the battery
Assuming the average solar irradiance is half the value of your answer to (e), and the Sun shines for the entire day length in (d), calculate:
g) The area of the PV panel required, if its conversion efficiency is 20%
if the ambient air temperature is 15°C and the nominal-operating-cell-temperature is 32'C, calculate:
h) Module operating temperature in your village/town/city at 15:00 on May 15
A solar water collector will be used at a different site in England, with an example of its summer performance data shown in the following Table. Note, the specific heat capacity of water, Cw = 4187 .1/kg°C. If the collector area is A = 3 m2 and the test flow rate is m = 0.04 kg/s:
i) Complete the three remaining columns in the Table
j) By plotting an appropriate graph, extract collector characteristics Nut) and FR(UL)
k) Submit the labelled graph as part of your answer
|
Solar Radiation G(W/m2) |
Ambient Temperature Ta(0c) |
Inlet Temperature Ti(0C) |
Outlet Temperature To(0C) |
(Ti-Ta)/G |
Q = mCw(Ta - Ti) |
η = Q/AG |
| 1 |
905 |
24.2 |
89.1 |
92.5 |
|
|
|
| 2 |
911 |
24.2 |
89.9 |
93 |
|
|
|
| 3 |
915 |
24.1 |
89.5 |
92.8 |
|
|
|
| 4 |
905 |
23.9 |
78.2 |
82.6 |
|
|
|
| 5 |
908 |
24.8 |
77.9 |
82.4 |
|
|
|
| 6 |
907 |
24.5 |
77.5 |
82 |
|
|
|
| 7 |
906 |
23.9 |
43.8 |
51.6 |
|
|
|
| 8 |
904 |
24.3 |
44.2 |
51.9 |
|
|
|
| 9 |
911 |
24.5 |
44 |
51.4 |
|
|
|