How can I convert that Watt peak rating to Megawatt?

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SUMMARY

The discussion focuses on calculating solar energy output (E) from a solar farm using the formula E = r x GB x A x L, where r is panel efficiency, GB is solar irradiance, A is total module surface area, and L accounts for losses. The user initially calculated a watt-peak (Wp) rating of 328,697 Wp but faced confusion regarding unit conversions and the implications of losses. After corrections, the user calculated the output for 5,254 solar panels, yielding 1.944 MWp, but expressed concerns about the simplicity of the calculations and the need to factor in sunshine hours and losses.

PREREQUISITES
  • Understanding of solar panel efficiency (e.g., 19.08%)
  • Knowledge of solar irradiance (e.g., 1.30 kW/m²)
  • Familiarity with calculating power output from solar panels
  • Basic grasp of unit conversions (e.g., W to MW)
NEXT STEPS
  • Learn how to incorporate sunshine hours into solar energy calculations
  • Research the impact of losses on solar energy output
  • Study the differences between peak megawatts and annual megawatt-hours
  • Explore advanced solar energy modeling tools and software
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Solar energy engineers, renewable energy analysts, and anyone involved in optimizing solar farm performance will benefit from this discussion.

t0mm02
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Homework Statement
E= r x GB x A x L
Relevant Equations
E= r x GB x A x L
Hello everyone. I need to calculate solar energy output (E) from a solar farm. The calculations are based on values from total module surface area in m² (A), panel efficiency (r), solar irradiance (GB) and losses (L) due to dust, cold temperature and ageing, which is estimated to be 0.75. Since the energy required from the PV modules has already been calculated, it is possible to analyze if the energy output is enough to satisfy the energy demand. The following formula is used to calculate the solar energy output (E):
  • E= r x GB x A x L
  • E= 19.08 x 1.30 x 10193.70 x 0.75 = 328697 Wp, which is the total watt-peak rating
How can I convert that Wp to Megawatt?
 
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t0mm02 said:
Homework Statement:: E= r x GB x A x L
Relevant Equations:: E= r x GB x A x L

Hello everyone. I need to calculate solar energy output (E) from a solar farm. The calculations are based on values from total module surface area in m² (A), panel efficiency (r), annual average solar irradiance (GB) and losses (L) due to dust, cold temperature and ageing, which is estimated to be 0.75. Since the energy required from the PV modules has already been calculated, it is possible to analyze if the energy output is enough to satisfy the energy demand. The following formula is used to calculate the solar energy output (E):
  • E= r x GB x A x L
  • E= 19.08 x 1.30 x 10193.70 x 1.3 = 328697 Wp, which is the total watt-peak rating
How can I convert that Wp to Megawatt?
A Megawatt is a million watts, right?
 
Without units, your numbers don't mean much. You should add the units for each of the numbers. What does the efficiency r of 19.08 mean? 19.08%? If so, shouldn't you divide by 100? Also, you said L=0.75, but then you multiplied by 1.3. How can the loss be greater than 1? Also, since you have multiplied by the "annual average solar irradiance", why would you call this watt-peak? Isn't it average watts?
 
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phyzguy said:
Without units, your numbers don't mean much. You should add the units for each of the numbers. What does the efficiency r of 19.08 mean? 19.08%? If so, shouldn't you divide by 100? Also, you said L=0.75, but then you multiplied by 1.3. How can the loss be greater than 1? Also, since you have multiplied by the "annual average solar irradiance", why would you call this watt-peak? Isn't it average watts?
19. 08 is the efficiency of the solar panel, therefore 19.08 %, L= 0,75 but I made a mistake so I will change it. Solar irradiance is 1.30 kW/ m². Now that everything is corrected, do you have any advice or help to offer? thank you
 
t0mm02 said:
19. 08 is the efficiency of the solar panel, therefore 19.08 %, L= 0,75 but I made a mistake so I will change it. Solar irradiance is 1.30 kW/ m². Now that everything is corrected, do you have any advice or help to offer? thank you
Can you show me the new calculation, with the corrections, and with units added? Why do you call the 1.3 kW/m^2 the "annual average solar irradiance"? Isn't it the peak irradiance? Do you still need help on converting to MWatts, or is @PeroK 's comment enough? Are you trying to calculate the peak megawatts, or the annual megawatt-hours, or both?
 
phyzguy said:
Can you show me the new calculation, with the corrections, and with units added? Why do you call the 1.3 kW/m^2 the "annual average solar irradiance"? Isn't it the peak irradiance? Do you still need help on converting to MWatts, or is @PeroK 's comment enough? Are you trying to calculate the peak megawatts, or the annual megawatt-hours, or both?
I get a really low number that doesn't make sense as the solar farm has 5254 solar panels, I get less than a MW and doesn't matter what numbers I use my calculations do not make sense.

However, I have seen this calculations on a thesis that I have found and when I do the calculations for my solar farm it makes a lot more sense:
As described earlier, a solar panel in sunshine periods can normally generate 260 W of power. By assuming 30 solar panels mounted on the rooftop, the power generation for a tram operating on line 8 will be: Power generated by 30 panels = 30 × 260 = 7800 W = 7.8 kW

I see these calculations too simple though, he doesn't take into account sunshine hours or losses and I don't know how to introduce sunshine hours or losses into his calculations or even if it is needed to introducde them.
 
Please post the calculation again, like you did in post #1, with the corrections and with units. We can't help you if you don't show us your calculations.
 
phyzguy said:
Please post the calculation again, like you did in post #1, with the corrections and with units. We can't help you if you don't show us your calculations.
Power generated by 5254 panels = 5254 × 370 = 1943980 Wp = 1.944 MWp

These are my calculations but once again, I see these calculations too simple though, he doesn't take into account sunshine hours or losses and I don't know how to introduce sunshine hours or losses into his calculations or even if it is needed to introduce them.
 
t0mm02 said:
Power generated by 5254 panels = 5254 × 370 = 1943980 Wp = 1.944 MWp

These are my calculations but once again, I see these calculations too simple though, he doesn't take into account sunshine hours or losses and I don't know how to introduce sunshine hours or losses into his calculations or even if it is needed to introduce them.
OK, two questions:

(1) You said in post # 6 "a solar panel in sunshine periods can normally generate 260 W of power". So why did you use 370W here?

(2) What are you trying to calculate? Are you trying to calculate the peak megawatts, or the annual megawatt-hours, or both?
 
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t0mm02 said:
Power generated by 5254 panels = 5254 × 370 = 1943980 Wp = 1.944 MWp

These are my calculations but once again, I see these calculations too simple though, he doesn't take into account sunshine hours or losses and I don't know how to introduce sunshine hours or losses into his calculations or even if it is needed to introduce them.
here try this
##E = (r) (GB) (A) (L)##

That doesn't help much does it? Include in the units:
##E (MW) = (r) (GB \frac {kW} {m^2}) (A m^2) (L) ( \frac{MW} {1000 kW})##

You seem to know the number of panels; call that "N" and think of "A" as the area per panel:
##E (MW) = (r) (GB \frac {kW} {m^2}) (A \frac{m^2}{panel})(N(panel)) (L) \frac{MW} {1000 kW}##
 

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