Solar panel glare and lying panels flat

[Praemon]

Hi all,

So I'm wanting to add solar panels to my house and after getting a quote I have some questions on the intended installation. I live in a complex and below is a picture of what the houses look like. There's not much space on the roof and only about 4 panels will be going there. The rest would be placed on the garage and laid down flat. My questions are:

1) I understand lying panels down flat will reduce performance, but it should still generate adequate power? The garage roof has 5 degree decline and faces North-East. 6 panels will be placed there.

2) How much glint and glare can be expected from flat panels like this? It's not an issue from the ground since you won't really see them, but I'm worried there may be glare for neighbours looking out their top floor. From my reading the glare should not be significant enough to be an issue, but anyone had problems? There's no neighbours directly in front of the garage, but there are on the sides in varying positions.

The panels to be used are JA Solar 460W.

Thanks!

 

[AchmatK]

Hi all,

So I'm wanting to add solar panels to my house and after getting a quote I have some questions on the intended installation. I live in a complex and below is a picture of what the houses look like. There's not much space on the roof and only about 4 panels will be going there. The rest would be placed on the garage and laid down flat. My questions are:

1) I understand lying panels down flat will reduce performance, but it should still generate adequate power? The garage roof has 5 degree decline and faces North-East. 6 panels will be placed there.

2) How much glint and glare can be expected from flat panels like this? It's not an issue from the ground since you won't really see them, but I'm worried there may be glare for neighbours looking out their top floor. From my reading the glare should not be significant enough to be an issue, but anyone had problems? There's no neighbours directly in front of the garage, but there are on the sides in varying positions.

The panels to be used are JA Solar 460W.

Thanks!

View attachment 1351648

I can answer the first item as my panels are all at a similar inclination on my carport.

I get up to 90% of the rated output in summer months and it drops to 40% in winter on a clear day.

This is from my 10.37kwp solar array consisting of 34 panels all at 5°.

 

[Praemon]

I can answer the first item as my panels are all at a similar inclination on my carport.

I get up to 90% of the treated output in summer months and it drops to 40% in winter on a clear day.

This is from my 10.37kwp solar array consisting of 34 panels all at 5°.View attachment 1351662

Thanks for the info. I'd imagine having it around 30 degrees or so would result in better gains, but perhaps not that significant? What the installer mentioned - which I agree based on my searching - is that the brackets for the panels if mounted at an angle cost nearly as much as the panel itself, and so it's actually easier (and more aesthetically pleasing in this case) to just lay the panels flat and add more panels to compensate if needed.

 

[Mike Hoxbig]

Glare is dependent on the sun's position. Even if there is any that might be bothersome, it'll probably go away in like 30 minutes...

 

[Gordon_R]

Thanks for the info. I'd imagine having it around 30 degrees or so would result in better gains, but perhaps not that significant? What the installer mentioned - which I agree based on my searching - is that the brackets for the panels if mounted at an angle cost nearly as much as the panel itself, and so it's actually easier (and more aesthetically pleasing in this case) to just lay the panels flat and add more panels to compensate if needed.

Your decision depends on whether you plan to run a stand-alone system, or grid tied. Flat panels in winter will be terrible, and extra panels will be a waste in summer, but are a tradeoff if you choose the least-cost option.

 

[AchmatK]

Thanks for the info. I'd imagine having it around 30 degrees or so would result in better gains, but perhaps not that significant? What the installer mentioned - which I agree based on my searching - is that the brackets for the panels if mounted at an angle cost nearly as much as the panel itself, and so it's actually easier (and more aesthetically pleasing in this case) to just lay the panels flat and add more panels to compensate if needed.

That's exactly what I did. Added more panels instead of going with the brackets. Also not visible from the road.

 

[Praemon]

Your decision depends on whether you plan to run a stand-alone system, or grid tied. Flat panels in winter will be terrible, and extra panels will be a waste in summer, but are a tradeoff if you choose the least-cost option.

It's going to be grid-tied and supplement the power during the day to help reduce the bill each month. So I'm aiming for that balance between cost and production.

 

[Mike Hoxbig]

It's going to be grid-tied and supplement the power during the day to help reduce the bill each month. So I'm aiming for that balance between cost and production.

Just be cautious when using the term grid-tied, as you may end up getting something that you will later regret.

A grid tied system requires the grid to work. If grid goes down, your system goes down too.

What you're looking for is a hybrid inverter...

 

[Praemon]

Just be cautious when using the term grid-tied, as you may end up getting something that you will later regret.

A grid tied system requires the grid to work. If grid goes down, your system goes down too.

What you're looking for is a hybrid inverter...

Sorry, yes. You're correct. Hybrid I already have the inverter and battery installed, so it's just the solar panels now.

 

[HowTo]

See @Speedster Solar installation. You will get idea and if Body Corporate will allow?

 

[Speedster]

Here are some estimates for PV production based upon 1kWp at 5 degree and 30 degree inclination (north facing) for Cape Town.