Simple Planning PV generation question

[Prefersdirt]

A simple question about planning for PV. Below you see what my hours per day will be. Is my thinking along the correct lines by planning for the MINIMUM sun hours per day? Example: putting out 9x250W panels would give roughly 2.8kW for a day (250W panel * 9 Panels * .80 efficient * 1.57 hours).

Yes, I understand there can be additional outside the peak hours collected, but that amount would be negligible.

Whether or not this is enough for demand, that is another story. Just making sure I have calculations correct.



Thank you

 

[snoobler]

Consider that those numbers assume you're laying your panel flat on the ground. If you place them at optimal year-round tilt, the results will be better.



No, you can't collect additional outside peak hours. It's not negligible. It's not there. This is the equivalent peak production you get from ALL DAY charging, i.e., it is the total sum of solar radiation striking the panel all day. You can't count on more.

You should mount your panels at the prescribed 50° from vertical (40° from horizontal) and plan for 2.56hr of charging per day worst case if your goal is to provide the desired solar in the worst case.

Thus 9 * 250 * .85 * 2.56 = 4.9kWh/day

 

[Prefersdirt]

Thank you. My math was correct. I was not even worrying about the position of the panel (I know there is an optimal angle) - just if I was calculating correctly.

Your numbers are much better than mine! That is great news.

Thank you again.

 

[DASH]

.....the correct lines by planning for the MINIMUM sun hours per day?

Keep in mind that the Solar Insolation figures (hours) is the average for the month. You will have days where the amount of sun available will be substantially less then the average, and substantially more then the average.