Hi this is amy from the alte store. we’ve shown you tutorials already on the effect of shading on solar panels, and effect of the direction you point your panels, now we are going to show you the effect of tilting your panels. Now the angle that you select to mount your panels will depend on a few different things. If you have got just a straight grid tie system that is going to be on your roof and your roof it a normal average tilted roof, you’re really just going to put it on that, because chasing after every little last angle on.
A grid tie system quite often isn’t worth the extra money. but, if you’ve got an offgrid system, and you need to pull out every single watt hour you can out of the system, then angle really does come into play, quite significantly. So I’m going to show you the effect of what we’ve got here. So it is November 20, very close to the winter equinox, so the sun is very low in the sky. I’m in Massachusetts, so my angle up here, my latitude is 42 degrees. So if I want to maximize year round performance, I would want to set my panels at as close.
As possible to 42 degrees, because if you figure it’s going to be that, the sun is going to be that angle in the spring and the fall, as opposed to in the summer when it’s just going to be really high, or in the winter when it’s going to be very low. So you really need to figure out when you will be maximizing it. Do you have a winter hunting cabin that you need to maximize your winter, or a year round place, in that case, you’d want to put them at bit of a steeper angle to try to get as much power as you can during the short.
Winter days. if you just have a summer camp, you’re going to have it really up very high. If you’ve got an RV that you are just driving around with, odds are pretty good that if you just put it flat on the top of your roof, you’re going to be great, because you are probably going to be using it in the summer when the sun is the highest. So let’s actually see what affect this has. Now again, I’m at 42 degrees latitude in November, so I’ve got this at just over 50 degree angle. So I’m really pointing directly at the sun. Now you.
See up here, i’ve also got a meter, it’s an insolation meter, so it’s showing me the intensity of the sun. Solar panels are rated at the standard test conditions, which is 1000 watts per square meter. So right now at quarter of two in the afternoon, I’m almost at 900 watts per square meter. So I’ve got pretty good intense sunlight right now. And so I’m going to show you the volts and the amps. So my volts right now is 19.8 volts and my amps is .41 amps. So you know I’ve got little 5 watt panels, so they are going to be fairly.
Low. but you are going to see a pretty dramatic change here in the amps, but not so much on the volts. If you saw the other tutorials you’ll see that intensity of the sunlight doesn’t affect volts as much as it affects amps, and that’s true with most semiconductors. So I’m going to change my angle here. So I’ve got it at 35 degrees now. My insolation has dropped down to 712, by volts is still pretty high at 19.6, but my amps have dropped down to .34. Now if I go down a bit more here, now I’m at 20 degrees, which would be great in.
The summer, but november 20? not so good. my insolation’s down to 500 and something, 540, my volts is still, again, still fine at 19.4 volts, but my amps has dropped almost in half to .27 amps. If I drop down even further, so I’m pretty much flat, so this is something you’d see probably on an RV, my insolation is dropped down to 267 watts per square meter. My volts is still ok, it’s 18.8 volts, but my amps is .15 amps, so I’m really not getting much power out of these panel. So you really can see that the angle that you tilt them.
Does matter. so if you’ve got an off grid system, you might want to do something that you can have them adjustable angles, so that you can have it so that in the winter you are going to have it pretty steep, and in the summer you are going to have it pretty shallow. Now again, if you’ve got a grid tie system, quite often it isn’t worth it because the year round average is going to average out to be alright. But if you have got an off grid system where you really need to keep those batteries charged up in the winter,.