Panels on north facing roof in Hawaii?

[esg]

I live in Maui, Hawaii with the south roof facing 150 degrees south. The south side is all used up with panels, and the installer chose to put 3 panels on the north side when he could have fit 1 more on the southeast and 1 more on the southwest-so that there'd only be one left on the north. He explained it would look better and only be a 3-4 percent difference on the north side at Hawaii's latitude anyway.

I'm wondering if I should have been more persistant that he put the panels facing southeast and southwest, but he's the "expert", so I let him have the final say.

Is it that big of a deal being on the north facing side of the roof here in Hawaii?

[Mike90250]

When panels are NOT all in the same alignment, you need to have separate controllers for each facet. (unless he built giant racks to keep the north panels facing south like all the others)

Is this off grid, or on grid ? Voltage / amps / watts ??

[esg]

it's on the grid. 18 235 watt Schuco solar panels, 18 Enphase/Seimens micro-inverters. The roof is, I guess, at an average pitch. The arrangement is 7 panels (and a SWH panel) on the south, 4 on the southeast and southwest, and 3 on the north.

Anyway, I'm just wondering how less effecient those panels on the north side are going to be compared to having put some of them on the souutheast and southwest.

[Wy_White_Wolf]

it's on the grid. 18 235 watt Schuco solar panels, 18 Enphase/Seimens micro-inverters. The roof is, I guess, at an average pitch. The arrangement is 7 panels (and a SWH panel) on the south, 4 on the southeast and southwest, and 3 on the north.

Anyway, I'm just wondering how less effecient those panels on the north side are going to be compared to having put some of them on the souutheast and southwest.

Being a micro inverter setup the orintation won't affect the other panels. (What Mike was hinting towards) To guess how much the north facing panel will lose depends on the pitch of the roof. If it's a low pitched you will see very little if any loss in the summer with more loss in the winter due to the lower inclination.

[russ]

You can play with PV Watts to get an idea.

I used a 1 kW DC system for Honolulu -

5

[esg]

follow-up

A follow-up for anyone interested. I just got hooked up to Enlighten today and was able to see what all my panels are doing. All the south facing panels have done 1.3 KWH each in 2 days use. Each of the Southeast panels have done 1 KWH. Each of the Southwest panels have done 1.1. And each of the North panels have done .7 KWH. I'm dissapointed to say the least- that the installer chose to put some of those panels there when he could have fit some on the southeast and southwest.
Oh well, it's winter and atleast I can expect better results come summer. When the installer said that the sun is past 90 degrees and will hit those north facing panels way better(but still, that's a lot of energy lost in the mean time).

[vracer]

If you have an iPhone, you can get a free app "tilt meter". That will give a pretty accurate number for your tilt. The compass app is also within 1-2 degrees of my "fairly good" hiking compass. (Don't forget variation.)

I have Enphase as well, and I am amazed at how little loss I get at fairly large inclination differences.

[sean211280]

If you have an iPhone, you can get a free app "tilt meter". That will give a pretty accurate number for your tilt. The compass app is also within 1-2 degrees of my "fairly good" hiking compass. (Don't forget variation.)

I have Enphase as well, and I am amazed at how little loss I get at fairly large inclination differences.

solar checker is a good free app too