Solar Panels and Solar Radiation Flux Density Help - Very Confused

[AN630078]

Agreed.No. It is meaningless to refer to the "intensity of the solar panel". The solar panel does not have an intensity. The intensity is the amount of power from the sun per square metre. 5.53W/m² is the intensity *calculated assuming the solar panels are 100% efficient*. So 5.53W/m² is not an accurate value of intensity (because efficiency is not 100%).

But we know the panels are only 20.8% efficient. So intensity must be (roughly 5 times) bigger than 5.53W/m².Yes but round to 3 sig. figs.No. First, 'example' is the wrong word. And we physicists don't use words like 'tremendous' in this context! Just say (for example) "300W/m² is an overestimate ...
'per day' is wrong. You = mean averaged over a day.
13.29055 is too many significant figures.

The most *accurate* values of intensity are the ones calculated allowing for efficiency. So you should be averaging the answers from 1c) and 2c), not from 1b) and 2b).
(204 + 26.6)/2 = 115Wm/s²
So the 300W/m² (assumed to be an annual average), compared to 115W/m², is roughly between two and three times too big.

Thank you for your reply and your continued insight.

2. c) Sorry my mistake, clearly I misused intensity here.

Question 3) "example" was the wording from the original question. Oh right, I will correct my average value also, thank you for remarking on that.

Can I verify that it would be correct to use an angle of 35 degrees when finding the intensity, as I have become a little uncertain?

 

[Steve4Physics]

Intensity is another word for energy flux density. But in common (maybe sloppy) parlance, people like to drop the word "density". So you just have to keep your wits about you as to whether someone is talking about the evaluated surface integral (formally flux), or the integrand (formally flux density)!

Yes indeed. In general, we have to be prepared to interpret loosely used terminology in context. It's very difficult for the younger students who have had little exposure to different terminologies.

 

[Steve4Physics]

Can I verify that it would be correct to use an angle of 35 degrees when finding the intensity, as I have become a little uncertain?

I can't verify that. The wording in the question is unclear. 35º is is simply my best guess using the available information, as I explained in message #21. Is this a written piece of work you have to hand-in? If so precede it with a statement such as:
"The direction of solar radiation relative to the panel is unclear. I have assumed an angle of incidence of 35º".
You will not be penalised if the angle is not 35º because the question is so obviously poorly-worded.

 

[AN630078]

I can't verify that. The wording in the question is unclear. 35º is is simply my best guess using the available information, as I explained in message #21. Is this a written piece of work you have to hand-in? If so precede it with a statement such as:
"The direction of solar radiation relative to the panel is unclear. I have assumed an angle of incidence of 35º".
You will not be penalised if the angle is not 35º because the question is so obviously poorly-worded.

Thank you very much for your reply and for your advice, I admit I will probably use your statement. It is a question my physics tutor sent to me in a quantum physics revision package of questions, but I had not come across a homogenous problem to this before, at least not within the context. If you like, once I have feeback from them I can inform you of the angle demanded by the question. Thank you again

 

[Steve4Physics]

I worried you might think that, but I assure you not. Hence the Like.

Thankyou!

 

[Steve4Physics]

Thank you very much for your reply and for your advice, I admit I will probably use your statement. It is a question my physics tutor sent to me in a quantum physics revision package of questions, but I had not come across a homogenous problem to this before, at least not within the context. If you like, once I have feeback from them I can inform you of the angle demanded by the question. Thank you again

You are welcome. Yes, it would be interesting to learn what the intended angle actually is!