A 50 kw interactive PV system has 15% system losses in a location getting 5.4 peak sun
hours per day average throughout the year. What would be the expected annual
energy putout?
Give this one a try later!
83,768 kWh
What is the largest array size if you are using a 24V battery bank and 20A charge
controller?
Give this one a try later!
280W
,What is the solar altitude angle?
Give this one a try later!
The angle between the horizon and the sun
Which type of PV system can dissimilar PV module types be used with little or no
system loss?
Give this one a try later!
A system that uses Ac PV modules that are coupled only to the Ac system
Which is the best way to determine the state of charge of a typical flooded lead acid
battery?
Give this one a try later!
Hydrometer testing
A 1MW inverter with 1200kW of PV is operating on a sunny day with 780W per square
meter
of irradiance and a cell temperature of 45oC and dc to ac derating of 95%. What is
the expected
inverter output power? Assume a typical temperature coefficient of power of
-0.45%/C
a. 1MW
, b. 1.1MW
c. 908kW
d. 809kW
Give this one a try later!
D 809kW
Explanation:
We are looking for different derating factors and we can see three of them
here:
1. irradiance below 1000W/m2
2. cell temperature above 25C
3. given derating of 95%.
We need to get derating numbers for these factors:
For irradiance if we have 780W/m2 out of 1000W/m2
:
= 0.78 derating for irradiance
For temperature we are going to lose some power.
First, we are going to determine our difference in temperature from how
the modules were tested,
which was 25C.
45C - 25C = 20C
Then we multiply our difference in temperature (delta T) by the temperature
coefficient for power.
20C × -0.45%/C = -9% change in power
Since we lose 9% out of 100% then
100% - 9% = 91%
Change to decimal 91%/100% = 0.91
0.91 derating for temperature; our last derating was a given 95% or 0.95
Now we multiply our PV capacity of 1200kW by the derating factors:
1200kW × 0.78 × 0.91 × 0.95 = 809kW
We should double check that the 1MW inverter can handle the output of
809kW, which it can
without clipping.
Therefore, we would expect this system to get somewhere near 809kW
hours per day average throughout the year. What would be the expected annual
energy putout?
Give this one a try later!
83,768 kWh
What is the largest array size if you are using a 24V battery bank and 20A charge
controller?
Give this one a try later!
280W
,What is the solar altitude angle?
Give this one a try later!
The angle between the horizon and the sun
Which type of PV system can dissimilar PV module types be used with little or no
system loss?
Give this one a try later!
A system that uses Ac PV modules that are coupled only to the Ac system
Which is the best way to determine the state of charge of a typical flooded lead acid
battery?
Give this one a try later!
Hydrometer testing
A 1MW inverter with 1200kW of PV is operating on a sunny day with 780W per square
meter
of irradiance and a cell temperature of 45oC and dc to ac derating of 95%. What is
the expected
inverter output power? Assume a typical temperature coefficient of power of
-0.45%/C
a. 1MW
, b. 1.1MW
c. 908kW
d. 809kW
Give this one a try later!
D 809kW
Explanation:
We are looking for different derating factors and we can see three of them
here:
1. irradiance below 1000W/m2
2. cell temperature above 25C
3. given derating of 95%.
We need to get derating numbers for these factors:
For irradiance if we have 780W/m2 out of 1000W/m2
:
= 0.78 derating for irradiance
For temperature we are going to lose some power.
First, we are going to determine our difference in temperature from how
the modules were tested,
which was 25C.
45C - 25C = 20C
Then we multiply our difference in temperature (delta T) by the temperature
coefficient for power.
20C × -0.45%/C = -9% change in power
Since we lose 9% out of 100% then
100% - 9% = 91%
Change to decimal 91%/100% = 0.91
0.91 derating for temperature; our last derating was a given 95% or 0.95
Now we multiply our PV capacity of 1200kW by the derating factors:
1200kW × 0.78 × 0.91 × 0.95 = 809kW
We should double check that the 1MW inverter can handle the output of
809kW, which it can
without clipping.
Therefore, we would expect this system to get somewhere near 809kW
